ADF08 Timber Supp Covers Layout 1 25/07/2018 15:44 Page 1 ... · a revolution in timber in architecture, as designers and specifiers increasingly embrace the material’s combination

TIMBER INARCHITECTURE08.18

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Timber in architecturesupplement

CONTENTS

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Industry news

COMMENT: The disruptive power of tall timberKevin Flanagan of PLP Architecture explains how the firm’s pioneeringresearch projects to build unprecedented tall engineered timber structures is driven by an agenda of increasing quality of life in ‘smart cities’ of the future

COMMENT: Why timber is the answerADF caught up with Jeremy English of Sӧdra to discuss why he feelstimber is the solution to the UK’s housing crisis, and how the material canhelp architects adopt less labour-intensive, offsite building techniques

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Swimming among the timbersA competition-level swimming pool has been constructed at a Surreyschool, integrating a high level of quality in the design of its timberelements while embracing its ancient woodland surroundings. AdamCossey from the project’s architects Hawkins\Brown, tells Jack Woolerhow it was achieved

Keeping the past in viewArchitect RO&AD’s timber watchtower project in the Netherlandsengaged the community in innovative ways to generate a new enthusiasmfor the area’s rich history. Sébastien Reed reports

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Going with the grainGregg Wright of Reliance Veneer explains how the demand for decorativetimbers combined with modern manufacturing techniques not only makesenvironmental sense, but can also enhance design

The membrane methodAdam Ford and John Mellor of Protect Membranes discuss how to achievelow U-values using membrane technology with low emissivity

The timber revolutionSarah Harding of Accsys Group reports on how the UK is experiencing a revolution in timber in architecture, as designers and specifiersincreasingly embrace the material’s combination of beauty andenvironmental advantages

The most sustainable material of them allSean Parnaby of West Port says that the timber industry is graduallywinning the war against misconceptions about what he claims is not onlythe oldest, but the best fenestration material

PROJECTS

FEATURES

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FROMTHE EDITORThere is a strong case to be made that timber has now become architects’ favourite material,

following a few decades when steel and glass (not to mention the perennial 20th centurycontender, concrete), dominated. Architects, driven by the twin desires to build more sustainably

and with wellbeing at the core, have always turned to timber. However with modular housing nowbecoming flavour of the month/year, the triple threat is going to lead to some waves breaking across thewhole construction industry.

The realities of embracing not only volume housebuilding, but a new construction approach in the form ofmodular timber, seem to have proved more daunting than expected for Legal & General. Notwithstanding,the insurer now looks to be ready to build its first modular timber homes, fresh from its new factory.Apparently, L&G Homes struggled to find CLT of the desired tolerances to do what it wanted, whichshows that while the CLT revolution is truly that, doing it in practice is far from simple.

L&G Homes aims to build between 10,000 and 15,000 homes a year within five years, and owning CalaHomes means that it has a foothold in sites, meaning it has at least some of the challenges covered. It isgoing to build 650 homes for rent on a brownfield site it has acquired next to a new Crossrail station inWoolwich, which sounds like the ideal showcase to present what modular CLT can do.

The big issue is that this kind of innovation is really going to put the cat among the pigeons in terms of theUK’s traditional (some might say moribund) adherence to brick-and-block house construction. Whileapartment blocks have embraced various alternative materials over the decades (and are arguably a betteruse of land), housing tends to be in the grip of the major volume builders, who prefer the supply chainsand methods (not to mention the density levels) they know, and can control.

Modular timber is of course an entirely different way of doing it, ensuring things are sorted pre-site, andwith minimal time and effort – comparatively – spent on site. The beam-and-post simplicity of theTallwood House project in Vancouver (which was reported in ADFMarch 2018), shows just what ispossible in tall buildings – an 18 storey timber structure, albeit with concrete cores. The question is,whether major UK builders will embrace, or resist, the rise of timber in housebuilding.

In this supplement devoted to design and construction using timber, we cover all bases, from awatchtower in the Netherlands, to PLP’s staggering proposals for tall urban towers constructed entirelyfrom wood. We hope you find it illuminating reading.

James ParkerEditor

ON THE COVER...Pompejus Tower by RO&AD Architecten is a structurebuilt from modified timber and steel in Halsteren, theNetherlands, and designed to lean at a sharp 60 degree angle, pointing towards a historic fort.

For the full report, go to page 18Cover image © Katja Effting

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At seven storeys, construction firm CCG(Scotland)’s recently completed EllerslieRoad development is being hailed asScotland’s tallest timber building. It is also Scotland's first multi-storey

domestic CLT building, and its BuildingWarrant approval has set a precedent inScotland as a result of evidence suppliedto Building Standards Scotland, GlasgowCity Council and Scottish Fire &Rescue Services.Built on the banks of the River Clyde at

Yoker, a town just west of Glasgow,Ellerslie Road provides 42 one, two andthree bed contemporary mid-market rentapartments for Sanctuary Homes, part ofSanctuary Group. The new building, whichwas designed by MAST Architects,optimises the efficiency of CLT with sixapartment modules arranged around onecentral stairway in a ‘T’ shaped form.Apartments are designed around a standard template used by CCG for allresidential units, however CLT’s ability toachieve long, uninterrupted spans allowedfor a flexibility in the layout of apartmentsfrom floor to floor which would havebeen more constrained with traditionalforms of construction. Engineer Smith and Wallwork were

responsible for the design of the CLT

superstructure, working collaborativelywith Eurban at detail design stage toensure a smooth offsite manufacture andonsite assembly process. The entiresuperstructure is built from Stora EnsoPEFC certified CLT including the commonareas and lift shaft. The lift shaft’sstructural walls are formed by 100 mmthick CLT panels tied together to form arigid tube with the shaft independent fromthe CLT separation wall between lobbyand apartment. The shaft is restrainedlaterally at each of the seven floor levels,with the panels forming the lobby slab andcapped with a 120 mm thick CLT ‘lid’ usedto fix the hooks to install the lift withoutthe need for any steel lifting beam.A bespoke platform is used to support

the superstructure due to the lightweightnature of CLT and the exposure to windloadings along the river. The superstructureincludes design features to provideenhanced resistance to disproportionatecollapse, and this has encouraged theInstitution of Structural Engineers(IStructE) to start a review process for PartA3 – ‘Building Regulation DisproportionateCollapse’ as it has recognised that there area number of forms of construction thatwould benefit from a review. 1240 m3 of CLT was used in the

construction of Ellerslie Road, whichequates to a total of 757 tonnes of CO2being removed from the earth’s atmosphere.Other key benefits of building with CLTinclude the material’s inherent air-tightnessand thermal properties, which mean thatresidents will benefit from energy savingswhen compared to traditional methods ofconstruction. Solar PV panels have alsobeen installed on the roof providinglong-term energy savings on residents’energy bills. Building with CLT resulted in reduced

construction time thus minimising impacton the surrounding community, with theentire seven-storey superstructure installedand wind and watertight in just 16 weeks. Ellerslie Road is the subject of two

academic research programmes looking atfactors including CLT’s airtightness,acoustics, thermal performance,productivity, LCA/whole life costing, andthe building’s interaction with wind.

Edinburgh Napier University hasintroduced an MSc on TimberArchitectural Design and Technology –thought to be the first of its kind in the UK.The programme is designed for

graduates in architecture, architecturaltechnology and other constructionprofessions who want to become partof the growing international movetowards innovative and high-performancetimber building.The MSc will equip students to work as

a design professional within the timbersector – one of the fastest growing parts ofthe building industry in many countriesaround the world.The programme has been developed

by Edinburgh Napier’s Institute forSustainable Construction in consultationwith professional bodies and the timber industry.Institute director Professor Sean Smith

said: “Our market research shows thatemployers in the UK timber building

sector are facing severe skillsshortages and similar gaps exist in manycountries overseas.”He added: “These employers are

looking for graduates with a combinationof technical know-how and commercialawareness in the design, manufacture andassembly of timber buildings and struc-tural systems. We have designed theprogramme to address this demand.”The university said that graduates of the

programme will be “equipped for employ-ment in design-build firms, fabricators,builders and developers; along withprofessional and technical roles in theassociated architectural and engineeringconsultancies”.

MSc on timber architecture launchedEDUCATION

Scottish CLT scheme sets a precedent

RESIDENTIAL

© CCG (Scotland)


The essence of our firm’s design is innovation, be it the world'ssmartest and most sustainable building yet, The Edge inAmsterdam, research proposals to improve urban movement

(SkyPod and CarTube), or to build taller than ever before in timber– the Oakwood Timber Tower series. All have at their core the aimof making our quality of urban living and wellbeing better. By 2050 the residential population of 150 of the world’s great

cities are projected to double. The existing challenges of insufficienthousing in London will become more acute. With populationincreases, cities will naturally densify, high-rise solutions willpredominate, and the CO2 footprint will increase massively withoutmitigation and active intervention. Can we meet the challenge?Our goal should be to improve the quality of life and freedom of

choice, allowing cities to thrive. The provision of housing seems anintractable urban challenge however. Cost seems to be driving awaythe best and most innovative idea makers – the millennials – as thecity gentrifies. The younger innovators on which the city ultimatelydepends are dispersed and forced away.Can we advance a new paradigm, reducing the seeming disruption

and extortionate costs of residential housing development throughthe harnessing of innovations such as robotics, Big Data,crowdsourcing, and the latest materials?

In support of smart citiesSmart cities of the future will be incubators that hatch innovativeideas, such as the new logistics apps, like Blockchain, that arecreating a more direct and responsive global marketplace. Londonneeds to rethink and realign its urban economic imperatives, toinclude greater influence of millennials in transforming the design ofour cities to meet their needs, incorporating 5G networks.As The Edge illustrates, ‘smart’ buildings flourish within smart

cities, and 5G will drive technology, from AI to health benefits inoffices from WELL Standard-like research and city design initiatives. Can we make daily life in our future cities a healthy experience,

reducing stress while increasing stimulation? Can design,architecture and materials be used to promote this healthfulness andde-stressing? Based on science and anecdotal evidence, the answerseems to be that engineered mass timber looks to have terrificpotential to improve urban dwellers’ quality of life.

Provocative proposalsPLP Architecture, with University of Cambridge Centre for NaturalMaterial Innovation, and structural engineers Smith and Wallwork,are collaborating on provocative feasibility research into mixed-useengineered mass timber/CLT high-rise towers for 21st century cities.The Oakwood Timber Tower proposals – one in London, and twoin the Netherlands – have been designed to improve our sense ofurban wellbeing, while being a response to anticipated future needs.Oakwood Timber Tower 1, a feasibility study for an 80-storey,

315 metre engineered mass timber and CLT tower at London’sBarbican, was hugely provocative for the construction industry. Itcontains a total of 1,000 ‘micro-housing’ units, in a 1 million ft2

mixed use tower, with new low-rise terraced accommodation aboveexisting structures. For the second iteration, Oakwood Timber Tower 2, ‘The Lodge’

was put forward with innovative Netherlands-based developerProvast NL. This project extended our knowledge of the potentialof engineered timber technology with a 130 metre centralised ovaldesign, as a more ‘real-world’ initiative. A series of ‘straight’

Kevin Flanagan of PLP Architecture explains how the firm’s pioneering researchprojects to build unprecedented tall engineered timber structures is driven by a wideragenda of increasing quality of life in ‘smart cities’ of the future

The disruptive power of tall timber

COMMENT

Courtesy of PLP Architecturefor developer Provast NL

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This project extended our knowledge of the potential

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www.storaenso.com/buildingsystems

three-storey glulam columns rise up within the hyperboloid towerform, this slender basket weave grid shell creating a dynamic‘airframe’ silhouette (see image below). Oakwood Timber Towers 3 is the most recent investigation and a

further iteration of the concept. The Lodge 2/Treehuis, again in theNetherlands, employs a cellular ‘tube within a tube’ construction.

Timber benefitsOur team has long been investigating the myriad benefits ofengineered mass timber. As a tower, engineered mass timberhas the potential to create an architecturally more pleasing, relaxed,sociable and creative urban experience; free, abundant, renewableand sustainable. Beyond the engineering and the sequestering of CO2, we as

humans have an affinity for nature, and timber. We are calmer andmore sociable when this natural material is in sight, our heart rateslows, we are less stressed, and apparently, more sociable; suchsettings evidently promote healing.People naturally associate timber interiors with the out of doors,

and some believe that the ‘phytoncide’ VOCs produced by timberare similar to the benefits of walking in a forest glade, claiming theyboost our immune system. Tests have shown that it lead to increasedconcentration in children of all abilities. Claims have also beenmade that in timber buildings one half of our brain gets ‘smarter’,we recover faster from surgery or illness (perhaps related to timberinteriors’ restfulness), energy levels increase, and sleep improves. As a harvested natural material, mass timber has a high visual

appeal to the human psyche, encouraging a sense of wellbeingamong residents. Modular cross-laminated timber (CLT) establishesa new level of precision, quality control and fire protection; bringinga new structural aesthetic and elegance in form. As well as being faster in construction, and less disruptive to

the local neighbourhood, modular CLT construction is quieter, socould also conceivably be used to extend many existing concretebuildings upwards substantially. For example, we understand that arecent feasibility study was done in Toronto to double the height ofan existing Four Seasons Hotel. As a provocation to the industry, we are stretching the

theoretical limits of plant-based materials with our tall timberconcepts, nearing, or going just beyond the easily feasible. Thisrequires further collaborative study including establishing ongoingtesting programmes.

Mixed-use residential high-riseThe use of timber as a structural material in tall buildings is an areaof emerging interest for a variety of potential benefits; the most

obvious being that it is a renewable resource, unlike prevailingconstruction methods using concrete and steel. The research is alsoinvestigating other potential benefits, such as reduced costs andimproved construction timescales, increased fire resistance, andsignificant reduction in the overall weight of buildings. There is 40per cent less waste immediately, and greater potential for secondand third use for the material.Our disruptive research into tall engineered timber buildings

also looks towards creating new design opportunities. Timberconstruction may have a wider positive impact on urbanenvironments and built form than we have currently envisioned,and offers opportunities not only to rethink the aesthetics ofbuildings, but also the logistics and cost; in light of this newtechnology and potential savings of production based fromcomputer-driven precision – BIM, GC, and Blockchain – androbotic staged construction methods. Building faster, lighter, atbetter quality, with improved resilience, and in a significantly moreenvironmentally responsible way.The light and high precision prefab components lead inevitably

to automated and robotic construction methodology and ‘flatpack’ cost efficiency. In Canada, which uses a high degree ofmodular timber, construction is 10-15 per cent cheaper now – onecan well imagine with a far greater sourcing and a great volumeand potentially doubling of product perhaps a 50 per centreduction could be achieved. The 20 per cent time savingsshould be possible to be reduced as well to say 50 cent with fullerproduction take up.

Housing futureThe average home in London is £540,747, thats £135,000 or 25per cent higher than say Boston in the US. One wonders can all thepromised efficiencies of Big Data be brought to bear on to meet anoncoming demand. Can the market achieve new efficiencies in thehousing market, what would happen to the London market if theprice were halved, and construction times were significantlyreduced, would London see a renaissance as a vibrant home ofyoung new ideas post-Brexit ? Despite harnessing new technology and new forms of

shared financing like crowd-sharing, and with Big Data andBlockchain logistics brought to bear, we can only streamline analready overly complex and burdensome methodology. We arebetter to invest the notion of people and cities, and harnessingtheir new ideas for the future, than to promote older, laboriousand uneconomical methodologies. We need to look again with neweyes at established methods which are now lacking. One new idea, crowd-sharing debt for new micro-housing

developments, can make the broader populace direct investors inthe quality of their cities. This could be part of the solution toestablishing new housing models better suited to young urbanprofessionals in idea industries, and key workers.Similarly, we are finding engineered mass timber to be a

truly 21st century material, as a response to several challengesincluding increasing CO2, and growing high residential demand,globally. As our society moves by necessity towards the creation ofsmart cities and valuing idea creation, this ‘New’ 21st centurymaterial seems to also answer future potential by making ourcities better places to live together; better places to think a newand act anew.

Kevin P. Flanagan is senior partner at PLP ArchitectureInternational

Courtesy of PLP Architecturefor developer Provast NL

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What do you see as the main challenges facing theUK housing industry?Government commitments, underpinned by the prospect of Brexitdepleting the labour force and an ever-increasing necessity forsustainability, means the housing industry cannot possibly deliver300,000 new homes a year using traditional building methodsalone. The coming years will inevitably see scrutiny turn towardhow these houses will be built, how quickly they can be built, andhow much money they’re likely to cost. Timber may prove to bethe answer that is needed.

So, what’s so special about timber?First and foremost, timber is the ultimate sustainable buildingmaterial, which is an important asset given this government’s plansto reduce carbon emissions by 3 per cent each year up until 2050.

As trees grow, they naturally absorb harmful carbon dioxide,locking CO2 into the wood rather than releasing it into theatmosphere. Timber’s overall embodied energy is also the lowest ofany mainstream building material. This factors in energy expended

through building, production and transportation, typicallyaccounting for around 30-50 per cent of a project’s entire carbonfootprint. It takes very little energy to convert trees into timber forconstruction, for example, while the building process typicallyrequires a fifth of the vehicle deliveries demanded by concrete.Aside from this, its insulating properties make buildings cheaper,greener and easier to heat post-construction.

Timber is also lightweight, versatile and easy to handle andinstall – all of which helps reduce construction time by around athird and typically result in less-expensive building. It doessometimes mean that timber is thought of as a weaker form ofconstruction, but that certainly isn’t true. Timber is remarkablystrong and durable, guaranteeing that regardless of speedyconstruction, there’s no compromise in quality.

How do these qualities help facilitate offsite modular housing?At a time when the construction industry is under increasedpressure to build quickly and sustainably, timber offers an often

ADF caught up with Jeremy English of Sӧdra to discuss why he feels timber is the solution to the UK’s housing crisis, and how the material can help architects adoptless labour-intensive, offsite building techniques

Why timber is the answer

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https://www.sodra.com/en/

inspirational alternative construction solution. The material’sability to streamline the offsite manufacturing process can help cutbuild time by as much as 50 per cent and a timber frame can beprecisely pre-cut and easily put together with less manpower, fewerdeliveries to site, and minimal debris left behind.Manufacturing in a controlled factory environment also means

that the great British weather is never a problem! It’s less likelythere will be any defects, risk of injury is reduced, and with greaterpotential to automate more steps of the manufacturing process,dependence on traditional skilled labour is reduced. All thesefactors help to cut costs, making timber construction adramatically more cost-effective form of construction thantraditional building methods.

Are we seeing people’s perceptions of timberconstruction changing in the UK?Here in the UK timber construction is making great strides. Legal& General, for example, took over 9,000 homes from RichmondCouncil and committed to building thousands of timber-framedflats and houses offsite for Richmond Housing Partnership (RHP).RHP bought them for at least 15 per cent below the standard costfor onsite construction and is set to rent them out for just £600-£700 per month. This is staggering considering rent for a single-bedflat in the Richmond area typically costs upwards of £1,000. It’s agreat example of timber construction being used to help delivertruly affordable homes.We’ve also very recently seen Mayor Sadiq Khan agree to

contribute £50,000 to fund a ‘developers’ toolkit’ to help simplifythe construction of offsite homes in London. It’s a significant stepforward for modular housing in London and representsrecognition that modular housing truly can help fix the UK’s‘broken’ housing market.The case for timber outside the capital is also strong. Lovell,

Morgan Sindall’s housebuilding arm, has recently signed a £45mmodular housing deal with Homes England under theGovernment’s Accelerated Construction initiative. 200 homes willbe built with modular closed panel, pre-insulated timber framesand roof cassettes in Leyland, Lancashire. Lovell has said that thismethod could double the speed of construction.There is, however, still work to be done. Timber frame

construction currently accounts for a massive 76 per cent ofhousebuilding in Scotland, but just a quarter of housebuilding in

England and Wales. Factory-based construction was up 15 per centin Germany and Japan last year and structural timber exports tothe US are expected to continue increasing. With timber alreadyleading the way in other parts of the world, the UK must step up itsuse of timber to help achieve its own housebuilding objectives.

What potential obstacles are there to the progress ofmodular homes?Although modular homes are typically less expensive thantraditional building methods, acquiring sites and constructingthe factories to put them together can be costly, which maymean we see a somewhat slower uptake from certain housebuildersand developers.Legal & General (L&G), however, spurred on from last year’s

Autumn Budget, has looked to accelerate its housebuilding havingalready launched a £55m offsite housing factory in Yorkshire in2016. It is the largest housebuilding factory in Europe andsubsequently delivered homes to the Richmond HousingPartnership discussed earlier.James Lidgate, L&G Homes CEO commented that its

multi-tenure approach to housebuilding could help them“achieve a 50 per cent improvement in delivery,” suggesting thateventual housebuilding capability more than makes up for theinitial expense.

What benefits does timber offer architects?Timber’s natural beauty and versatility is hard to replicate, and atimber-framed building can provide a highly desirable aesthetic.Timber naturally grows more slowly in colder climates, resultingin a tighter grain and growth rings, which not only signifies betterstability and greater strength, it also provides an additionalaesthetic feature. And, if you’re working with timber that will be exposed and on

show, it offers a wide range of aesthetics that give great designflexibility. It can vary in colour and texture, be painted in anycolour, waxed and varnished, carved, cut, glued and nailed – or justleft as it is. It can also be clad in external materials, allowing it tocomplement specific local regulations and planning requirements.It’s no surprise that we’re seeing more and more timber

structures being built. It’s a great selling point for eventualoccupants to know that their home or office has not damaged theenvironment but has in fact locked in and helped mitigate theeffects of otherwise potentially harmful carbon dioxide.Speed and ease of construction are also two key benefits. Waugh

Thistleton Architects, for example, has long championedsustainable timber construction and put together Murray Groveand Dalston Lane – two landmark projects. Nine-storey MurrayGrove was the first tall urban housing project to be constructedentirely from pre-fabricated solid timber and was put up by a teamof four in just 27 days. Dalston Lane required just 111 deliveries ofmaterials during construction, compared with over 700 deliverieson a typical concrete and steel project. And earlier this year,Sumitomo Forestry revealed plans to build W350 – a 70-storey,350-metre timber skyscraper in Tokyo. W350 would become theworld’s tallest timber structure and the tallest building in Japan.Projects like these not only help raise the profile of timber

construction, but also offer all the evidence and reassurance peopleneed that timber is the building material of the future.

Jeremy English is sales director at Sӧdra – Sweden’s largest forest-owner association

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www.warmcel.co.uk

www.primeoak.co.uk


https://www.hawkinsbrown.com/

The new pool for City of LondonFreemen’s School, in Ashtead,Surrey, uses state-of-the-art timber

construction and offsite fabricationmethods to create a sustainable buildingthat sits gently within its context. Designedby architects Hawkins\Brown, the 25 metre,six-lane competition-standard pool includesa multipurpose teaching and events space,as well as a panoramic view connecting theusers with the surrounding woodland.Freemen’s School is a co-educational

private school for day and boarding pupils,situated in Ashtead Park. Founded in 1854in Brixton by the Corporation of London,its original purpose was to educate orphansof the ‘Freemen of the City.’ Having moved to Ashtead in 1926, the

school is now set in 57 acres of parklandin the heart of Surrey. As part of amasterplan which included the renovationof several buildings across the school, thearchitects have created a new facility thatblends well with this historic property,matching the site’s educational prestigeand natural beauty. Mole Valley District Council granted

outline planning permission for themasterplan in 2011. The new pool was akey part of the application, replacing itsformer iteration. Although originallyplanned for a later phase, priorities shiftedwhen the old pool was destroyed by a firein 2014.

The architects utilised innovative offsitefabrication techniques to create the newbuilding’s timber frame. The materialpalette complements the external setting –the building wrapped in zinc, creating astriking environment internally andexternally for users and spectators alike.

New beginningsHawkins\Brown architects were appointedin 2011 to undertake the masterplan for the school. Phase one was the design anddelivery of the new music block andboarding accommodation, which wascompleted in 2014.The swimming pool marks the second

phase, and further phases move onto thelarge, Grade II listed main house, a newplayground, and enhancements to thelandscaping of the school grounds.This was not always the plan, however,

as Adam Cossey, partner at the firm,explains: “The masterplan originally hadfour phases; the boarding accommodationand music school was to be phase one, themain house and dining area phase two,three was going to be the provision of anenergy centre and a swimming pool, andphase four was going to be landscaping forthe entire campus.”He continues: “However, the fire in their

existing pool area, which was very close tothe main house, catalysed the school tomove on with the development of the

A competition-level swimming pool has been constructedat a Surrey school, integrating a high level of quality in thedesign of its timber elements while embracing ancientwoodland surroundings. Adam Cossey from the project’sarchitects Hawkins\Brown tells Jack Wooler how it was achieved

Swimming amongthe timbers

CITY OF LONDON FREEMEN’S SCHOOL POOLASHTEAD, SURREY

BUILDINGPROJECTS

All photographs © Jack Hobhouse

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Even if they’re just visiting,they can really understandthe structure – it’s a veryhonest buildingAdam Cossey, partner, Hawkins\Brown

swimming pool faster than planned, and sothat became phase two.”

Following this change, along with a newheadmaster coming in, the masterplan wasrevisited: “The priority for the school wasto replace the swimming pool as soon aspossible. This provided an opportunity tore-evaluate the proposed location withinthe original masterplan and to consolidatethe school’s sports facilities.”

Another factor in the move was access.“If you’ve got a swimming gala youwant to move vehicle traffic away fromthe academic heart, and encouragemore pedestrianisation.”

Working on a sensitive site, thearchitects and school had to thinkcarefully about how to integrate the poolinto the landscape once it was relocated.The building is positioned to minimise itsimpact upon the landscape and itsvisibility from the school’s main house. Apartially submerged lower ground floornestles the building into the landscape,while hand formed standing seam claddingin a dark copper colour responds tohistoric features of the main house,addressing issues raised by boththe local planning authority and the

conservation officer.“On paper, the conversation with the

planning department seemed challenging,but after taking both the conservationofficer and the chief planner around thebuilding post completion, they weredelighted with it.”

The sloping gradient on one side ofthe site gave the architects “a fantasticopportunity to effectively give the pool an‘upper ground’ and ‘lower ground,’” saysCossey. “By extending the pool at lowerground level, we were able to havewrap-around extended glazing on thenorth-east side of the building, producingan amazing view from the pool to themature ancient oak woodland.”

Also, on the upper level, and tying inwith the main entrance on the upperground where the property increases inheight, they included an event space andclassroom that overlooks the lower level ofthe pool.

Inside & outInside the finished building, the architectsdesigned a clear circulation, from the mainentrance space and reception area on theupper level, following through to the

14 CITY OF LONDON FREEMEN’S SCHOOL POOL, ASHTEAD, SURREY





classroom and event space. Views fromboth the event reception and event spaceinto the pool are framed by deep windowseats, along with blinds to achieve visualseparation if necessary. A staircase leads down towards the pool,

with doors on one side leading to thechanging rooms and then the pool, andanother door which leads into the spectatorseating area.Glazing has been used around all four

walls to flood the structure with light.“When it came to daylighting, we had to becautious,” says Cossey, however. “We didn’twant glare on the water surface, becausethat would impede competitionswimming.” The south facing glazing hasan opaque finish, so there’s no chance ofany direct sunlight onto the water.“What we can have, however, is

indirect sunlight, i.e. from the north eastfacing elevations. We’ve got floor to ceilingglass on the lower level, and that allowsplenty of daylight into the building.” On the upper levels, glazing wraps theevent space, as well as the building’s mainreception area.Swimming pools are frequently heavily

serviced and environmentally controlledbuildings. The final design of the Freemen’sSchool pool was developed to remainrelatively free of services and the associatedclutter. All of the environmental controlsystems, as well as the water treatmentplant, are located around the perimeter of asubterranean base, which at its centrehouses the pool itself. To introduce airflow into the hall,

discreet slots are located in the floorbeneath the glazing, reducing the condensation risk and evaporative heat lossfrom the pool.The design achieved a BREEAM Very

Good rating – the building’s carbonemissions are reduced by 10 per centthanks to roof PVs. Further carbon savingsare planned later in the project, with thenext phase of works on the main house toinclude a CHP energy centre that willutilise the pool as a heat sink. Environmentally-conscious products

have been specified such as Foamglasinsulation, which is made of recycled glass. To minimise the building’s impact on the

landscape, the swimming pool’s lowerground floor is partially submerged. This‘beds’ the structure to some degree into thesurrounding scenery, and preserves a largenumber of the existing trees, with thehighest point of the gently pitched roofidentifying the main entrance.

15CITY OF LONDON FREEMEN’S SCHOOL POOL, ASHTEAD, SURREY


This provided an opportunity tor



A box of two trianglesThe pool has an interesting geometry withslightly uneven elevations and a roofcomprised of two triangular zinc sections. It resembles a rectangular box which hasbeen slightly squashed at two corners andfolded along its top. The ridge junctionbetween the two triangles runs diagonallyacross the space, creating an offset, dynamic rhythm externally and internally,expressed in the CLT ‘ribs’ that hold up the structure. Adam explains how the building’s form

was developed during the design process:“We began with the end requirements ofthe buildings. Then, we took a rectangleand extruded it, and you’ve got quite aconventional box, we then simply pusheddown two adjacent corners of that box, andpicked up the remaining two corners.”A standing seam zinc cladding in a dark

copper colour was chosen to cover thebuilding’s unconventional exterior, withseams forming vertical ribs which areintended to help the structure blend intothe landscape. Another reason standingseam cladding was used is because it is amore traditional material, responding tokey features of the school’s main house.

Off-site timberLed by contractor Gilbert-Ash, theconstruction of the pool is centred arounda glulam portal frame braced with CLTpanels. The use of engineered timberprovides a fast, efficient, carbon neutralmethod of construction that provides bothstructure and internal finish.The all-timber construction also has a

number of advantages in dealing with thechallenges of a pool environment – it isresilient, a thermal insulator and corrosionresistant. On site, the erection of theglulam portal frame and cross-laminatedtimber walls and roof took just over threeweeks. This allowed the detailed designand full construction of the building to bedelivered in one year.The natural internal surface of the

structural timber roof and walls is leftexposed, and has been stained white.Here, the material acts as a complemen-tary feature to the external setting andhelps to create a special environment toswim in.This is enhanced by the structurally

expressive roof geometry with its series ofshifting glulam frames, the result being avisually dynamic space. Cossey comments: “The design

allows students and spectators to really

understand how the building has been puttogether. Even if they’re just visiting,they can really understand the structure.”He adds: Structurally, it is a very honestbuilding.” A softwood spruce is used throughout –

in the CLT panels and glulam beams –which, as Cossey says, “ties in nicely withthe surrounding woodland.” The elementswere formed offsite, with all panels, beamsand columns prefabricated by Wiehag inAustria, then assembled on site. The wholesuperstructure was erected in just undertwo weeks.Cossey says CLT is being used

increasingly on a wide range of projects:“People are starting to see the potential ofCLT. A little over a decade ago it was amethod of construction that was widelydisregarded in the UK, whereas todaycontractors are increasingly suggesting thisas the principal method of construction.”BIM software helped optimise the

process. “Using BIM technology we cangenerate 3D models with relative ease,”says Cossey. “This allows us to create avery complex geometry, which can beimaged on a computer, then sent straightto factory to be manufactured.”

CollaborationCossey notes the “fantasticallycollaborative” experience between theclient, design team and contractor. Hecontinues: “Where there were challenges,they were dealt with swiftly. From day one,there was a very positive, can-do mentality.It was an absolute pleasure to work witheveryone involved.”Roland Martin, headmaster of the

school, gave a glowing testimonial on thefinished building: “We are overwhelmed by the beauty and quality of the newswimming pool – it is a fantastic new assetfor the school and the local community. “We were impressed by the swift

construction of the pool, and how it fits inthe woodland space and complements theschool as a whole.”It is not often that fires are a blessing in

disguise, but it appears to be the case here,with the school now having a strikingarchitectural asset for its students.Relocated to its proper location as one ofthe school’s sports facilities, and takingadvantage of, as well as enhancing, itswoodland location, it’s not hard to seewhy it has picked up RIBA South East andnational awards. Lucky students andvisitors will be able to ‘swim among thetrees’ for decades to come. �

PROJECT FACTFILE

Architect: Hawkins\BrownStructural engineer: Eckersley O’CallaghanServices: Skelly and CouchContractor: Gilbert-AshLandscape designer: BD LandscapeTransport engineer: MotionEcology advisor: AspectArboriculturalist: TreeLineBREEAM assessor: SRLProject management: Pick Everard

We have been trulyimpressed by the swiftconstruction of the pool,and how it fits in thewoodland space andcomplements the school as a wholeRoland Martin, headmaster, Freemen’s School

16 CITY OF LONDON FREEMEN’S SCHOOL POOL, ASHTEAD, SURREY




www.jamesjones.co.uk/ewp

All Images © Katja Effting


https://www.ro-ad.org/

Construction of the defensive WestBrabant Water Line was started in1627 by the Dutch states of Zeeland

and South Holland as a series of forts,protecting the then main water navigationfrom Middelburg to Dordrecht againstattack from the Spanish Armada. Over thecenturies, the Line has repeatedly comeunder attack from foreign aggressors. Fortde Roovere north of Bergen op Zoom andoriginally located near the water before landreclamation, was largest of the forts. Over the decades, it fell into major

disrepair, to the point that it was almostcompletely hidden, until 2010 when localauthorities initiated a gradual project ofregeneration. Starting by re-excavatingcanals and trenches to restore the fort’sfrontiers, the programme has switched todeveloping playfully symbolic architectureacross the site to celebrate its past.Pompejus Tower in Halsteren is the latestaddition – a seemingly gravity-defyingwatchtower with extra functions built-in.RO&AD’s involvement in the project

emerged from its local connections, asfounder and architect Ad Kil recalls: “I’djust finished a small job on the then mayor’shouse, and she asked me to make up somesketches for a watch tower and a bridge forthe site. We then slowly got involved.” Since then, the practice has secured

the role of resident architect on the fort,with enviable creative freedom overfuture additions.

Functional growthFort de Roovere was an important focalpoint in the landscape for the Dutch.Separating saltwater and freshwater, it was

at the middle of the dyke line, overseen bythe fort towards Bergen op Zoom to thesouth and Steenbergen to the north.Pompejus Tower, taking its name from thefirst commander of the fort, rises 34 metresabove the surrounding land, and 26 metresabove its immediate foundations, thedifference made up by the fort’s banksfrom which the tower protrudes.The steel-framed structure is enveloped inmodified timber, and leans at a sharp 60degree angle towards the outer edges of thefort, inverting the slopes and reflecting theangles of the banks beneath. Formally, thetower loosely resembles the shape of atriangular prism, wider at its base, taperingtowards its upper extremity. The brief simply required “a watchtowerthat can see the waterline – that was theonly condition,” Kil explains. Its genericnature gave the architects freedom to throwideas around. “It had to be more than that,”says Kil. RO&AD devised a provision thatweaves an open-air theatre and visitorcentre into the scheme. “We saw thepotential of Fort de Roovere being a basefor local theatre groups and buildingconnection with the cities nearby.” The two outward-facing facadeelevations are clad in timber panels, plus athird inner side – host to a series ofobservation platforms at incrementalheights – left open. A central doorway atground-level provides access to a visitorcentre nestled into the base of the tower,while another doorway one level up leadsto storage facilities for theatre groupscoming to perform at the fort.A square of concrete slabs at the foot ofthe tower’s open elevation functions as a

Architect RO&AD’s timber watchtower project in the Netherlands engaged thecommunity in innovative ways to generate a new enthusiasm for the area’s rich history. Sébastien Reed reports

Keeping an eye on the past

POMPEJUS TOWERHALSTEREN, THE NETHERLANDS

BUILDINGPROJECTS

INSPIRED BY NATUREA Voronoi pattern emphasising radial growth from‘seed points’ outwards was used on the exterior

19





A SUBMERGED BRIDGEConstructed before the adjacent tower and using thesame modified timber is a submerged ‘Moses Bridge’

theatre stage which is observable from eachof the platforms ahead. Multiple sets oftimber stairs within the tower double up asbenches at the lower levels, and providevertical access to each of the observationplatforms both to watch theatreproductions, and at the top level – andechoing the ancient fort’s original purpose,to watch the waterline.

Timber rationaleExplaining why timber was used as theprimary material for the tower, Kil says:“The original fort was built from sand,which is soft but durable at the same time.We wanted to replicate that, and use a softermaterial for the tower. Plus, all of thehistorical military buildings were made fromwood.” There was also the desire to alignthe tower’s design with the language of theexisting Moses Bridge, located just 150metres to the south.Like its submerged neighbour, PompejusTower features Accoya wood throughout – aNew Zealand grown Radiata Pine which

has undergone Accsys Group’s proprietaryacetylation process, whereby planks of thewood are placed into a pressurised tank ofacetic anhydride (high-strength vinegar) andare, essentially, pickled. The result is anon-toxic softwood with structuralproperties which rival and exceed eventropical hardwoods. Acetylation changesthe free hydroxyls within the wood intoacetyl groups. When the free hydroxylgroup is transformed to an acetyl group, theability of the wood to absorb water isgreatly reduced, rendering the wood moredimensionally stable and extremely durable,making it much more resilient to water, andless susceptible to rot; a crucial factor giventhe Dutch climate’s perennial wind and rain.“Tropical hardwoods were the onlyother choice, really,” explains Kil, whofavoured Accoya for its sustainablysourced fast-growing properties. “Therewas no doubt that we had to work with it,”says Kil.It was originally intended that thestructure be made entirely from wood, but

The timber and steelstructure leans at a 60degree angle towards theouter edges of the fort,inverting the slopes andreflecting the angles of the banks beneath

20 POMPEJUS TOWER, HALSTEREN, THE NETHERLANDS




to achieve sufficient structural integrity, amassive quantity of wood would have beenrequired, adding to existing budgetaryconcerns, so RO&AD resorted to atriangular steel framework – regulating costsand pleasing the structural engineers, whosupported the leaning structure with pilesdriving deep into the banks’ soil.

Sourcing stakeholdersInitial designs conceived a tower 21 metreshigh. However, after surveying the site usingdrones, the architects realised that thetower’s scale had to be increased to better seeover trees blocking views of the waterlinefrom ground level. With the extra functionsdesigned-in, and the height requirementincreased, the initial budget of €600,000 wasno longer enough to finance the project.

“We needed to get people more connectedto the tower. And we did that by crowd-funding and building the tower with localvolunteers both companies and individuals,”says Kil.

Using crowdsourcing, the project team

was able to raise an additional €70,000 incash for the scheme, as well as more than€300,000 in kind – in the form of expertisefrom local construction companies, labour,and building materials.

To foster closer ties with the landscapeand its history, the architects also wantedto get the local community involved in theconstruction process itself, however thetower’s complexity meant this was an evengreater challenge, as Kil explains: “Thedesign was really, really complicated,but we wanted to make it possible forvolunteers to screw the tower together. Sofirst, we went to a local school to get themput together a miniature model of thetower that we had designed – and theyweren’t able to. How could we expect themto assemble the real building?”

The fix came to RO&AD almost bychance. Kil recounts the story of a trip heand his fellow design partner, Ro Koster,took to a conference in St. Petersburg,Russia to present on various past projects.Also presenting was Toni Österlund from

21POMPEJUS TOWER, HALSTEREN, THE NETHERLANDS


much more resilient to water, and

l



Geometria Architecture, a Finnish digitaldesign practice, discussing a solution thatthey had devised that the RO&AD architectsrealised could be applied to the constructionconundrum at Pompejus Tower.Using a set of algorithms, Geometriatransformed the tower’s digital 3D modelinto factory-friendly blueprints which wereused to fabricate a full set of flat-packedtimber elements with matching instructions,allowing virtually anyone to assemble themby hand. This method not only reducedlabour costs, it inspired a sense of ownershipof the tower and a consciousness of thelocale’s rich heritage among volunteers. Part of the tower’s complexity rests in thecombination of a steel frame made up oftriangles overlaid by timber cladding panelsforming a ‘Voronoi’ pattern (similar to agiraffe’s spots). The fragmented design madefor components which could more easily bemanufactured, shipped and mountedtogether by unskilled volunteers. The patternobscures the triangular framework beneath,signalling timber as the key material, andslits between the facade panels naturallyilluminate the tower’s interior while allowingusers to observe the surrounding sceneryfrom varying heights.These panels are glazed at the levels of thevisitor centre and storage area, shielding theinteriors from the weather. As well as themore practical benefits, Kil also liked the

idea of using a design that “established anaesthetic link with nature”.

From local to globalThe new tower had its official opening inMarch 2018, with a christening of theopen-air theatre featuring live traditionalmusic, and an audience from the localcommunity unanimous in their praise of thenew, somewhat defiant monument. Themunicipality have since been busy curating asteady programme of performances fromregional theatre groups for the summer, withthe intention of further cementing the fort’splace in the future local cultural scene.Carved into the steps of the tower for allto see are the names of individual donorsand businesses who contributed help andexpertise to the project, which is likely toreceive visitors from across the globe, in thesame way the Moses Bridge has, as Kilexplains. “The bridge is featured in theChinese ‘Top 10 sights to see in theNetherlands’ guide” – leading to significantnumbers of Chinese tourists coming toHalsteren each year.The family of additions at Fort de Rooverecontinues to grow, with a new timberentrance bridge currently under constructionwhich will recreate the bridge access of theoriginal defences. Kil says that, comparedwith its counterparts, “this one won’t be aspecial thing – just a nice wooden bridge.” However modest it is, with sensitiveplacement into its historical context and thearchitects’ embracing of innovative andinclusive methods, it’s sure to be a keycomponent of the ongoing success of thissite. That success is largely down tocarefully-conceived timber buildingsre-energising a community’s connection withtheir built environment, and its past. �

Using a set of algorithms,Geometria transformed thedigital 3D model intofactory-friendly blueprintswhich were used tofabricate a full set of flat-packed timber elementswith instructions

PROJECT FACTFILE

Wood: Accoya (acetylated Radiata Pine)Location: Fort de Roovere, Halsteren, the NetherlandsWood engineering: Geometria, FinlandConstruction date: December 2017Opening date: March 2018Client: Municipality of Bergen op ZoomBuilder: Adviesbureau LüningContractors: Berghbouw, De KokBouwgroep, De News SoffersCarpentry: VKP BouwCost: €1.4m

22 POMPEJUS TOWER, HALSTEREN, THE NETHERLANDS





Have you ever looked at a beautifulpiece of furniture and wonderedhow the distinctive patterns and

figuring repeats are achieved, chances areit’s through the use of wood veneer.Veneer is typically produced from the

highest quality woods available andalthough production methods haveadvanced the basic technique has been usedfor thousands of years.Many people perceive solid wood to be

of higher quality than a product made usingveneered panels, but veneered panels havemany benefits over solid timber which canbe exceptionally heavy, can expand andcontract with moisture changes in theair, and even warp if the surroundingconditions are extreme enough. By contrast,manmade panels have wood fibres and gluecrossing in so many directions that thepanels are able to remain stable in some ofthe harshest conditions.The use of wood veneer in conjunction

with the advancements in laminated andfibre panels, such as MDF or plywood, givearchitects and designers exceptionalcreative opportunities. As well as being anenvironmentally sound choice, reducing thedemand on natural wood resources andhelping to limit deforestation, use of veneeralso makes sound economic sense, allowingdesigners to enhance furniture with unusualor exotic woods, the use of which would beprohibitively expensive in their solid form.Currently there are in excess of 120

natural species available for veneerproduction in Europe. Timber is a naturalresource and as such, no two logs areidentical, and even within the same species,logs will vary in grain pattern, colour andmarkings. There are many environmentalfactors that will determine the suitability oflogs for veneer production. Weatherpatterns in Europe are different to thosein North America and this gives rise todifferent grain structures. European timber

species often show more colour variationand the texture can be more course andbrittle than the equivalent American species.Veneer logs have to be carefully selected forquality, as manufacturing is an expensiveand exacting process.In Europe and the Americas, veneer is

typically cut into three standard thicknessesdepending on the application for which itwill be used, most commonly 0.6 mm withonly about 16 species being commerciallyavailable thicker. Timbers cut more than2.5 mm thick are normally classified as

Here, Gregg Wright of Reliance Veneer explains how thedemand for decorative timbers combined with modernmanufacturing techniques not only makes environmentalsense, but can also enhance design

Going with the grain

Veneer is typically produced from the highest qualitywoods available, and although production methods have advanced the basic technique has been used for thousands of years

23



http://www.relianceveneer.com/


sawn lumber rather than veneer.In order to reveal different grain patterns

logs can be sliced in a number of differentways; crown or flat cut, quarter cut, rift,and rotary cut. Unless rotary cut, veneerleaves are often relatively narrow, to coverlarge area. The leaves are matched andjoined to form larger sheets called layons.There are many different ways the leaves

can be matched using the grain pattern toyour advantage, some creating uniqueeffects and designs.Book matching is a traditional method

of matching the veneers by turning overevery other leaf, mirroring the leaf adjacentto it. Using this method, it is possible tocreate the most amazing ‘star bursts’ oncircular table tops or a pleasing matchacross wall panelling.Slip matching is much a more

contemporary method, as each leaf of veneer remains facing the same direction and is jointed next to each other to create an asymmetrical butuniform pattern.Random matching is possibly the

most natural of all the matching methods.

This involves taking leaves of veneer where the grain pattern, colour tone, width and grain structure vary and joining them producing a planked, morerustic look.As trends and fashions evolve,

veneer once thought of as traditional or old fashioned, such as oak, sycamore and beech can be transformed and brought up to date using natural or chemical dyes. Almost any type of woodcan be transformed into almost any colour or tone imaginable. This enables the production of veneers for specificrequirements and can provide a consistentuniform colour.The dyeing process combined with

modern technology means that it is nowpossible to engineer veneers to replicate rarenatural species that are becoming lesscommercially available, and consequentlyincreasingly expensive.There are truly endless possibilities when

choosing natural wood veneer.

A leading UK wood veneer specialist, GreggWright is sales director at Reliance

There are truly endlesspossibilities whenchoosing natural wood veneer

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The use of timber in construction isnow seen as a key route to addressthe UK’s housing shortage. The

Government’s target of 300,000 homeshas recently been increased to 340,000properties to be built in England alone,annually until 2031, to keep on track withdemand, according to a 2018 reportcommissioned by The National HousingFederation. With greater emphasis onmeeting this shortfall using alternativeconstruction methods, offsite timber framemanufacture is increasingly seen as aproven method to reduce build programmesand improve cost efficiencies, and, with aprecision in design that can be controlledwithin factory conditions, is currentlythe fastest paced sector within UKhousebuilding. Construction of timberbuildings is set to top 60,000 units in 2018,up from around 52,000 in 2016.

What is the challenge?Set against the backdrop of high demand,the need for efficient manufacture andmaximisation of build space to maintainaffordability, today’s specifier has toensure that materials for timber frameconstruction can meet fabric energyefficiency requirements by delivering lowoverall U-values for the structure. Current Building Regulations Part L1A

set upper limit U-values for each keyconstruction element (roofs, walls andfloors) as well as airtightness requirementswithin a structure. As the drive for energyefficiency continues, the Regulations alsodetail a Notional Dwelling specification,which is more onerous and demanding interms of U-values. In the case of a wall, atleast a 40 per cent improvement against theupper limit value is required. With the needto minimise energy loss from a propertyto lower the environmental impact, thearchitect needs to consider innovative waysto design a dwelling to ensure the notionalspecification is met yet is affordable to theend client. Using low emissivity, reflective membrane

technology with insulating propertieswithin the wall structure is ideally suited to

timber frame panel construction and is agood way to achieve these objectives.

How can the challenge beovercome with productspecification?The thermal efficiency of the structure must be optimised so that low U-valuescan be achieved for each constructionelement to meet the low Notional Dwellingspecification requirements. Taking the wallconstruction as an example, the use ofinternal breather membranes within thetimber frame panel facing two still airspacecavities either side of the insulation, can deliver added thermal benefits whenused with a reflective, vapour permeablebreather membrane fitted on the outer faceof the sheathing board on the cold side of the construction and a reflective air and vapour control layer (AVCL) on thewarm side.This combination of products ensures

thermal efficiency if installed with thereflective surfaces facing into the cavities,reducing the insulation needed within atimber frame panel while still achieving low U-values. This could mean a reductionin the thickness of rigid, high density PIRinsulation boards or a move to fibrous orEPS insulation without impacting on thewall’s footprint, thereby maximising landspace and affordability, yet deliveringstrong thermal performance. Designing airspaces within a timber frame wall panel

Adam Ford and John Mellor of Protect Membranes discuss how to achieve low U-valuesusing membrane technology with low emissivity

The membrane method

ABOVEProtect TF InterFoil used in a timber frame wallconstruction with cavity trays, mineral wool insulation,and internal/external reflective membranes

BELOWProtect TF InterFoil insulating breather membranewith reflective technology

25



http://www.protectmembranes.com/



enables developers to meet stringent targetswithout impacting on the timber frameconstruction process or significantlyincreasing the cost of manufacture.

To the owner and occupier, the long term integrity of the AVCL and theinternal/external breather membranes willensure that the full design benefits of athermally efficient envelope are achievedand ultimately enhanced due to the use of reflective technology.

How does a low emissivity cavitywork?When using reflective membranetechnology, the use of high purity, solidaluminium foil on the surface ensures themembrane forms a radiant barrier whenfacing at least a 20 mm unventilatedairspace within a wall construction. Thiscreates a low emissivity cavity, whichsignificantly reduces heat loss and raises thethermal resistance of the airspace whenfixed as per standard timber frame/studpractice and rafter centres. The correct use of internal and externalreflective membranes will effectively blockinfrared radiation and increase the thermalperformance of the airspace, allowing lowtarget U-values to be met.

How can manufacturers help?To ensure that the right product is usedappropriately within a timber frame panelto provide the required performance, anexperienced manufacturer should beconsulted – one which offers a full range of wall construction membranes and canensure a solution based approach. Somemanufacturers offer a free U-valuecalculation and condensation risk analysisservice using membranes as part of thebuild-up to assist specifiers with theiroverall design.

Adam Ford is head of technical and John Mellor is product manager at Protect Membranes

The correct use of internaland external reflectivemembranes will effectivelyblock infrared radiationand increase the thermalperformance of theairspace, allowing lowtarget U-values to be met

Low emissivity, reflective membrane technology is ideally suited to timber panel construction

26





Running earlier this year at the RocaLondon Gallery, ‘Timber Rising:Vertical Visions for the Cities of

Tomorrow’ presented an intriguingglimpse into the future of architecturaltimber solutions. With engaging andin-depth discussions from industry-leadingexperts throughout the public exhibition,topics such as ‘Forests and SustainableCities’ and ‘A Revolution in Construction:Hand in Hand with Nature’ were exploredin depth.The panellists – Dr Layla McCay

(Centre of Urban Design and MentalHealth), Michael Ramage (Centre forNatural Material Innovation at TheUniversity of Cambridge), Kevin Flanagan(PLP Architecture) and Elina Grigoriou(Grigoriou Interiors) – have all utilisedcross laminated timber (CLT) extensivelyin their latest projects and research.

Urban practicality combines withaesthetic beautyCommenting on the context of urbandensification and the associated need tobuild upwards, Clare Farrow, co-curator ofthe exhibition, pinpointed a key issue:“New luxury towers built of concrete,steel and glass present exciting andsymbolic visions of this future, but there isalso a flip-side. The problem is that citiesalready account for 75 per cent of globalpollution and consumption ofnon-renewable resources. In the UK forexample, the energy consumed in theconstruction and operation of the builtenvironment accounts for almost half ofthe country's carbon dioxide emissions.”Timber offers a direct solution to

this problem; its carbon credentials areunparalleled; it is five times lighter thanconcrete; and its thermal properties makeit an ideal material for both interior andexterior applications. In particular,modified timber provides compellingenvironmental advantages overnon-renewable carbon-intensive materialssuch as plastics, steel and concrete. The

environmental impact of this timber can beassessed at all stages of its life cycle, fromcradle to grave.

Industry commentsKevin Flanagan, partner at PLP Architects,is just one of the many who has recognisedthe outstanding potential that timber canoffer. He has designed a conceptual timberskyscraper at London’s Barbican (alsodiscussed on page 6 of this supplement),which was originally intended to beprovocative, to test both public andindustry reaction.At the event, Kevin Flanagan discussed

the key construction benefits: “Timberis very light and extremely easy tomanoeuvre and because of this, structurescan be built inside a factory and thenshipped to site in ready-to-assemblecomponents, meaning much shorter buildtimes on-site.”Furthermore, due to its lightness,

timber can also be used to add to existingstructures, which may be of paramount

Sarah Harding of Accsys Group reports on how the UK is experiencing a revolution intimber in architecture, as designers and specifiers increasingly embrace the material’scombination of beauty and environmental advantages

The timber revolution27



https://www.accsysplc.com/


importance in an era where overcrowdingis becoming an increasing issue. Withnewfound vertical layering possibilities,architects may now be looking atadding density to existing structuresinstead of requiring new land. This is adirect benefit of a recent building buildingcode provision that allows for greatersoil load-bearing of old foundationsonce compacted.Flanagan enthused about the future

potential: “Within the next five to 10years, it is extremely likely that there willactually be someone who wants to buildone of these. Our clients are wanting atimber structure because it has a specialappeal to the market that they are goingafter and, in this, the final look of abuilding can be very market-driven.” In this context Flanagan remarked how

“products like Accoya wood open up anew world of cladding possibilities – as ithas been modified to protect against wateringress and other elements.” It ismanufactured using an acetylation processso that even when it is cut or jointed, theability of the wood’s cell walls to absorbwater is reduced by approximately 80 percent. This structural change greatlyimproves the wood’s dimensional stabilityand results in a stronger, more durableproduct while reducing coatingmaintenance requirements, making it anideal solution for cladding applications. Throughout the exhibition, quotes

adorned the walls of the Roca Gallery inpraise of timber and the progress it hasmade. One in particular – from Michael

Green of MGA (Michael GreenArchitecture) – truly resonated with thethemes of the evening’s conversation.“Buildings of late have become

increasingly sculptural in form, largelydriven by an aesthetic preference. Innature, beauty is driven by natural forces.In living organisms, beauty and form arenot an accident but rather an evolutionarymeans to propagate and survive. The shapeof a tree’s branch is not a rectilinear form,instead it has grown to satisfy the complexstructural needs of supporting its leaves,managing wind and reaching for daylight.The branches’ fibres align and thickenwhere needed, they slim down where not. “Buildings of the future will use these

same principles to make forms driven bypure structural need, using less materialwhile creative sculptural forms with trueengineering meaning. Only then willarchitecture truly evolve.”It would seem that architecture is now

truly in the midst of such an evolution.As heard in the panel discussion, it istrue that increasingly more architects,interior designers and psychologists arerecognising the potential and, indeed, theimportance of this material. In creatinghighly functional masterpieces all over theworld which will allow people to live andwork more freely and happily, they areenabling people to experience the worldthrough a different medium.

Sarah Harding is head of corporatemarketing & communications at theAccsys Group

The environmental impactof this timber can beassessed at all stages ofits life cycle, from cradleto grave

28





There’s a growing awareness thattimber isn’t the expensive,maintenance-heavy material many

people think it is – and that its poorreputation in some quarters has nothing todo with timber itself, but stems insteadfrom the cheap and shoddy mass-producedwood windows of the mid-20th century.

But one of the most stubborn timbermyths concerns sustainability. Many peoplestill incorrectly assume timber windows anddoors are bad for the environment, butthat’s not true. Timber, when it’s ethicallysourced, is the greenest fenestrationmaterial of them all.

Increasingly, you hear claims that PVCuis the most eco-friendly and thermallyefficient fenestration option on the market –understandable given growing publicinterest in minimising their environmentalimpact, and ever-rising heating bills.

But they’re false. A unit’s energyefficiency is determined by the glass, not theframe – and far from being the greenestoption available; PVCu is actually the worstpolluter among window materials.

Making a PVCu window pumps 160 kgmore carbon dioxide into the atmospherethan making a timber one does. Andrecycled PVCu windows can contain lead,cadmium and mercury, all of which arereleased as toxic gases when exposed toextreme heat, making them highlydangerous in fires.

Many people associate timber withdeforestation – people irresponsibly cuttingdown sections of forest, and never replacingthe trees that are removed. But ethicaltimber is a different phenomenon entirely.

Sustainable timber products come fromwell-managed forests, where new trees areplanted to replace those that are harvested.

Sean Parnaby of West Port says that the timber industry is graduallywinning the war against misconceptions about what he claims is notonly the oldest, but the best fenestration material

The most sustainable material of them all

29



https://www.west-port.co.uk/


Planting new trees means that even moreCO2 is stored, making sustainable timberproducts better than carbon neutral.

Academics from Heriot Watt University,renowned worldwide for its constructionexpertise, conducted a comprehensiveLife-Cycle Analysis on a variety oftimber windows and compared them withPVCu alternatives.

They found that using timber to makewindows could make ‘a significantcontribution to low-carbon building’. Thisis for two key reasons. The first is thattimber itself is a low-carbon material, andthe second is that timber offers lowthermal transmittance, meaning timberwindows offer excellent thermal efficiencyand allow homeowners to use less energyto heat their homes.

Wood was also found to have‘significantly lower’ environmental impactthan PVCu alternatives. In fact, all thewood windows tested as part of the studywere concluded to have negative globalwarming potential and be carbon negativeover their entire 60-year average lifespan.

These outstanding ecological credentialsare reflected in the fact that the BuildingResearch Establishment’s Green Guide rateswood windows as A or A+ for theirminimal environmental impact.

Timber is also highly durable, with somewell-made wooden structures lasting forcenturies. It also helps to meet increasinglystrict government regulations aimed atreducing the construction sector’senvironmental impact. With timber, youdon’t just ensure you meet today’slegislative requirements, you future-proofyour project against measures that couldbe introduced in future, and increaseyour chances of getting through theplanning process.

In fact, timber is without a doubt one ofthe most environmentally friendly, highperformance building materials availabletoday and for the future.

Sean Parnaby is managing director of West Port

Sustainable timberproducts come from well-managed forests,where new trees areplanted to replace thosethat are harvested

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www.sashwindow.com

www.sioox.org.uk

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ahmarra.co.uk

www.owatroldirect.co.uk

www.osmouk.com

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Osmo revives aged wood with power gelOsmo UK brings aged wood back to lifewith its powerful cleaning agent, OsmoWood Reviver Power Gel. This product hasbeen especially developed to restoreexterior wood, including wooden decking,timber cladding and garden furniture, back to its original colour and character.Made from environmentally friendly and

biodegradable ingredients, it is free from harmful solvents, chlorinecompounds, amines and harmful odours. One coat is sufficient torevive external wood back to its natural colour and appearance.

www.osmouk.com

PYC Group’s most ambitious projectIn 2016, PYC Group started planning themost ambitious project they’d done; a newoffsite manufacturing facility and Passivhaus(designed) offices in Welshpool, Wales. Twoyears later, The House Building Factory andoffices are fully operational. The main designchallenges for the offices were heating

methods and overheating risks. The timber frame structure is heavilyinsulated with Warmcel, so the decrement delay is as good as it gets,and with Welsh temperatures rising to 32oC, the upstairs officeaverages 25oC, downstairs 22oC; not too bad at all.

www.pycgroup.co.uk

Speedy building with CaberShieldPlusNorbord’s flooring product, CaberShieldPlus,is being used by Sylva Design & BuildSolutions at Graven Hill, Bicester where theyare creating new affordable homes. SylvaDesign & Build Solutions, who offer low-risksustainable turnkey home solutions, usedCaberShieldPlus on their timber framefast-track build project. Norbord’s tough P5

chipboard flooring has a permanent waterproof coating on both sides.CaberShieldPlus is designed with the ever-changing and unpredictableBritish weather in mind.

www.norbord.co.uk

Artisan Panel doors for luxury homesSpecialist door manufacturer, Ahmarra havesupplied bespoke panel doors for a number ofstriking high-end residential properties fromtheir Artisan Panel Door Collection. The Artisanrange has been designed specifically forarchitects, developers and interior designersworking in the luxury residential sector andoffers a wide choice of door and panel designsand additional joinery components. Proud to fly

the flag for British craftsmanship, the Artisan Panel Door Collectionoffers the very best quality in terms of design and materials.

www.ahmarra.co.uk

Piveteaubois launch HEXAPLIWhen the 10,000m2, €15 million plantcomes on stream in September it will bethe first integrated, large-scale crosslaminated timber (CLT) productionoperation on French soil, with start-upoutput of 50,000m3 a year and capacity

to go up to 100,000m3. HEXAPLI, from Piveteaubois, is available inPine, Douglas Fir and Spruce in three to nine-ply variants. Floor andwall panels come in max 3.5m wide and 16m long. They can betreated to UC2 against insects and fungi, or, where specified suppliedin UC3.2 sapfree Douglas fir or UC4 autoclaved pine.

[email protected] www.piveteaubois.com

Bespoke, traditional timber windowsThe Sash Window Workshop recently carried outwork on a period property in Hertfordshire,manufacturing and installing timber windows.The company manufacture windows and doors attheir workshops in Berkshire, allowing them toensure the new joinery meets the high standardsthey expect. The materials are chosen to give thebest possible performance, combining minimummaintenance with maximum lifespan. They have

over 20 years’ experience replacing and repairing timber windowsand doors across London and the South.

[email protected]

Connecting Cross-Laminated TimberTo support the growing use of cross-laminated timber (CLT) in theUK and Europe, connector manufacturer Simpson Strong-Tie hasreleased an updated version of its ‘Connectors for CLT’ catalogue.Featuring a host of new products including heavy duty angle brackets,hold-down connectors and structural screws, this edition representsa complete set of solutions for the assembly of CLT buildings, as wellas steel and chemical mortar products designed specifically to connectthe entire structure to concrete. To further support the design and construction of CLT structures, Simpson Strong-Tie also has ateam of engineers based at its manufacturing plant in Tamworth,offering technical support and assistance. The new brochure can bedownloaded from the Simpson Strong-Tie UK website.

01827 255600 www.strongtie.co.uk


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A£140 million development to create anext generation shopping and leisurepark in Northamptonshire is using

JB Antislip Plus Smooth from Marley Eternitto provide a durable and effective externalanti-slip surface for visitors. Rushden Lakes, at Nene Valley in

Northamptonshire, opened in Summer 2017,and offers over 400,000 sq.ft of new retailand restaurant accommodation, together withleisure activities which are all set against thebackdrop of a lake.The unique project, which comprises a

30-acre development, will also link up fourexisting nature reserves, identified as Sites ofSpecial Scientific Interest (SSSI), to create theNene Wetlands, a one mile square naturalspace for visitors and wildlife to enjoy. As part of the project, more than 500,000

sq.ft of JB Antislip Plus Smooth decking wasused at the retail park development, creatinga linear length of around 40km.Gary Wilburn, director of design and

sustainability at HPW Architecture, which led the design and development of themasterplan for the 244-acre site, explainswhy, when selecting a decking solution tomeet the bespoke needs of the project, JB Antislip Plus Smooth, was the obvious choice. He says: “The unique nature of the RushdenLakes development is setting an entirely new

standard for the retail and leisure experience,and as such, we required a decking solutionwhich would not only deliver enduring antislip properties, but one which would also seamlessly fit in with the wider natural surroundings.“Having used JB Antislip Plus Smooth

previously, we were already reassured thatthe product could meet our bespoke needs

but furthermore, meet the wider objective of the development project to ensure we used the highest quality specialised materials throughout.”The timber decking boards are specifically

designed to provide a durable and effectiveexternal anti-slip surface to minimiseany risk of slipping – even in adverseweather conditions.JB Antislip Plus uses a unique formula of

resin-based aggregate inserts, which areinjected into the deck board grooves. For thesmooth boards required by this project,grooves are specially machined into theboards to receive the inserts. They are treatedto either Use Class 3 (MicroPro®) or UseClass 4 (Naturewood®) to protect the deckingand suit the project requirements. Emily Dix, Marketing Executive at Marley

Eternit, adds: “For a project, such asRushden Lakes, where huge numbers ofvisitors are expected, JB Antislip Plus Smoothdecking is an ideal solution, as it offersanti-slip properties which exceed HSLguidelines, but also seamlessly blends with thesurrounding environment, making it theperfect choice for retail and conservationareas alike.”

01283 722588www.marleyeternit.co.uk/decking

Multi-million pound development projectputs best foot forward with anti-slip decking


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Val-U-Therm PLUS® wall panelsachieve 0.08 W/m2K – probably thebest U-value wall in the world.

Couple this with Scotframe’s expertise &track record and the sky really is the limitwhen it comes to design of buildings that tick all the boxes on your clients’ wishlists. Key to achieving this extraordinaryperformance is that the insulation is injectedin off-site, quality-controlled factoryconditions. The foam expands into everynook and cranny, providing a best-in-classBR443 U-value correction factor of zero.As well as excellent thermal insulationperformance, details are available to minimisethermal bridging and give excellent airtightfabric levels.The Scotframe Val-U-Therm® building systemwas originally launched in 2011 and has beenused in over 8,500 homes with an excellenttrack record. A UK market leader in fulltimber frame packages for new housing andcommercial projects, Scotframe exclusivelyoffers the Val-U-Therm PLUS® closed panelbuilding system. This is accepted by financialinstitutions, NHBC, Premier Guarantee andCheckmate – the panels have a 60-yearminimum service life.Because it’s a hybrid of the best aspects ofSIPS and timber frame technology, coupledwith the latest advances in material science, itoffers much flexibility and innovation in the design and build process. The uniquecombination of design opportunities includes:• Can be used for walls, roofs and floors• All types of design and architecture, evencurved walls and roofs

• Can be thermally engineered to performas an optimum combination

• Unrestricted elevational treatments –brick, stone, render, cladding, tile,timber, etc.

• All interior finishes and treatments• Large-span roofs with vaulted ceilings,if required

• Dramatic open-plan layouts offeringlifestyle flexibility

• Extensive glazed features anduninterrupted roof-space living areas

• BBA accredited building system, includingin-fill panels in other building systemsCouple this with its exceptional thermal

performance and sustainability, Val-U-ThermPLUS® provides a straightforward and

cost-effective way for architects to hit energyefficiency, air permeability and otherenvironmental targets. It offers a fit-and-forget, future-proof solution, whatever levelof environmental specifications are required– for example, ‘A’ rated Energy PerformanceCertificates, PassivHaus or the highest levelsof energy saving and carbon neutrality.The patented Val-U-Therm PLUS® is

also inherently sustainable due to carefulsourcing of raw materials with a minimalenvironmental impact. Scotframe’s timber issourced from FSC and PEFC sustainablymanaged forests and the insulation in Val-U-Therm PLUS® panels is based on renewablevegetable oil, has zero ozone depletionpotential and is CFC, HFC and HCFC-freewith a Global Warming Potential of less than5. This means it has a BRE Green GuideA/A+ Rating – the same as straw balesor sheep wool yet is hydrophobic offeringflood mitigation.From the UK’s first PassivHaus for rent

(which won a Green Apple Award) toexamples that significantly exceed thePassivHaus standard, Scotframe hasbeen leading the way using Val-U-Therm®

technology in energy efficient building formany years. The Maryville PassivHaus delivered a total

primary energy demand of 69 kWh/m2a(exceeding the PassivHaus requirement of120 kWh/m2a). This ‘Fabric First’ approachis also suitable for commercial buildings – the

Rocking Horse Nursery at the University ofAberdeen, which caters for 78 pre-schoolchildren. achieved an air tightness of0.475 ACH.Hence Scotframe homes and buildings are

warm and draught-proof in winter, cool andwell ventilated in summer, healthy for all thefamily and enjoy remarkably low energy bills. Scotframe Val-U-Therm PLUS® allowsthe construction of typical family homes thatcan cost less than £95 a year to heat. The great news is that building to these

high standards is not necessarily more expensive or time consuming using ScotframeVal-U-Therm PLUS®. Edinburgh NapierUniversity compared the cost per squaremetre of superstructure using 10 differentbuilding systems. Scotframe Val-U-Therm® cost £1092 when

built to PassivHaus standards, whilst theother nine systems ranged from £711 to£1138 when built only to existing BuildingRegulations. It took 65 days to build aScotframe home to PassivHaus standards; theother 26 homes ranged from 49 to 126 daysto build, again only to Building Regulations. So, if you are looking to design a dream

home or superlative building – thinkScotframe Val-U-Therm PLUS®.Scotframe Timber Engineering and Val-U-

Therm are proud to be part of the SaintGobain Group of Companies.

01467 624 440 www.scotframe.co.uk

Design Flexibility & Performance from Scotframe

Denwell Cottage



www.piveteaubois.com/en/

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ADF08 Timber Supp Covers Layout 1 25/07/2018 15:44 Page 1 ... · a revolution in timber in architecture, as designers and specifiers increasingly embrace the material’s combination