North Shropshire District Council

Conservation Section, North Shropshire District Council,Edinburgh House, New Street, Wem, Shropshire, SY4 5DB.

T: 01939 238433/434/429 F: 01939 238422www.northshropshiredc.gov.uk

TRADITIONAL WINDOWS INNORTH SHROPSHIRE

A practical guide to repair and upgrading

2005

CONTENTS

Types of windowwindow glasswindow frames

Window detailsside –hung casement windowssliding sash windowsglazing barswindow ironmongeryshutters

Repair or replacement?

Methods of repairrecognising defectsoverhauling timber windowsrepairing timber windowssaving historic glass

Upgrading old windowsstopping draughts and rattles

Replacement windows

Painting windows

Do I need permission?

Where to get advice andinformation

INTRODUCTION

Windows are the ‘eyes’ of a building – theylet in light and give views out. And like eyesthey have a profound effect on theappearance and character of a building’s‘face’. Original windows are an integralpart of the design of a historic building andcan be important artefacts in their ownright, made with as much skill and ingenuityas a piece of antique furniture.

When it becomes necessary to repair orreplace windows in a listed building, or abuilding in a conservation area, it isimportant that the work is carried out in asympathetic and appropriate way to avoidspoiling the appearance of the building andreducing its value.

This booklet gives examples of the types ofwindow commonly found in traditionalbuildings in North Shropshire and explainstheir design and construction. Advice isgiven on appropriate methods of repairingand upgrading timber windows, and on theissues to be taken into account whenconsidering replacement.

TRADITIONAL WINDOWS IN NORTH SHROPSHIREA practical guide to repair and upgrading

This booklet has been produced byThe Conservation Section,Planning Services Department,North Shrophire District Council,Edinburgh House, New Street, Wem,Shropshire SY4 5DB

TYPES OF WINDOW

The evolution of domestic windowdesign from the late 1500s was closelyrelated to developments in glassmaking. Before this time windows in allbut the grandest houses consisted ofsimple openings formed in masonrywalls or as an integral part of thestructural frame in a timber-framedbuilding. Wider openings were oftensub-divided by vertical mullions into twoor more lights. Taller openings werefurther subdivided by horizontaltransoms. Windows would sometimesbe fitted with vertical wood or iron barsfor security and covered with oiled clothor sliding or folding timber shutters toreduce draughts.

Window glass

Towards the end of the 1500s windowglass became more readily available,although it was probably not in commonuse in smaller houses until well into the1600s. At this time window glass was inthe form of leaded lights - smalldiamond or square-shaped panes orquarries held together by a lattice oflead cames. The quarries were madeby blowing molten glass into a hollowsphere which was then cut open andspun rapidly until a thin disc or crownwas produced. When cool the disc wascut up into regular panes which,because of the limited size of the crown,were small to reduce the amount ofwaste around the edge.

As glassmaking skills developed itbecame possible to produce largercrowns – up to 1.6m in diameter – fromwhich larger panes could be cut. Theselarger panes gradually took the place ofleaded lights from the end of the 1600s.The familiar bull’s-eye occurred at thecentre of the crown where it wasattached to the iron rod or pontil whichwas used to spin it. Panes containingbull’s-eyes were regarded as waste andonly ever used in inferior situations suchas glazing in service rooms. Crownglass was the finest quality windowglass and prized for its sparkling, fire-polished appearance. It continued to bemade in much the same way until the1930s.

Another technique for making windowglass began to be used in the 1700s.Cylinder glass was produced by blowinga long cylinder which was slit along itslength then opened out and flattened.The quality of polish of cylinder glasswas inferior to crown glass but largerpanes could be made. By the early1800s glassmakers in America and onthe Continent had developed thisprocess to produce much largercylinders and it was this method whichlead to the large-scale industrialproduction of window glass. Nearly allwindow glass was produced by one ofthese two methods until the later 1800swhen more modern and mechanisedproduction processes replaced them.

The sparkling and distortedreflections in crown glassadd to a building’s visualinterest

Top: leaded light withdiamond-shaped panes

Above: a stage in themaking of crown glass

An unglazed medieval two-mullionwindow with wooden bars (only onesurvives) to keep out intruders

Window frames

The two main types of traditionalwindow are side-hung casementwindows and sliding sash windows.Within these groups there areconsiderable variations in design anddetail which depend to some extent onthe date of the window.

It is not uncommon to find more thanone type of window in the samebuilding. This may be because thebuilding has been altered or extendedbut often it relates to the varying levelsof importance given to different parts ofthe building. For example, the front ofthe building might have vertical slidingsash windows whilst the back hassimple side-hung casements orhorizontal sliding sash windows.Service wings usually have simpler,less costly windows than the higherstatus parts of houses.

WINDOW DETAILSSide-hung casement windows

The use of side-hung casement windowsin ordinary houses increased in the1600s, as window glass became moregenerally available and affordable.Sometimes it is possible to see wheregrooves or rebates for glazing andopening casements have been cut intothe frame of an earlier window. Openingcasements made of wrought iron werehung on simple pin hinges spiked into

wood, usually oak, frames and wereoften fitted with delicately forgedfasteners and stays. Leaded lights werefixed to the iron casements with leadrivets and wire. As larger panes of glassbecame available during the 1700sglazing fitted directly into rebatedcasements gradually superseded leadedlights. Older flat iron casements wereadapted to provide a rebate, sometimesmade from zinc, to support the glass andputty.

Left: vertical slidingsash window

Right: side hungcasement window

Right: Restored 3-lightmullion and transomwindow with leadedlights, iron casements andoak frame.Probably late 1600s.

1600 1700

1. 2.

3. 4.

Below: “Time line” showing the evolution of window design.1.Unglazed mullioned window. 2.Oak-framed window with iron casements and leadedlights. 3. Classically proportioned oak-framed window with iron casements andleaded lights. 4. Oak-framed vertical sliding sash window with thick glazing bars.5. Oak-framed window with iron casement. 6. Softwood vertical sliding sash with thinglazing bars. 7. Cast iron window. 8. Softwood casement window. 9. Vertical slidingsoftwood windows with ‘horned’ sashes. 10. Steel casement window

Although by the early 1700s this type ofwindow had become unfashionable itcontinued to be used in lower statusbuildings well into the 1800s. It enjoyeda revival from the late 1800s in buildingsinspired by the Arts and Craftsmovement.

Windows with side hung woodencasements were popular in small housesand rural buildings throughout the 1800sand early 1900s. There are also manyexamples of older window frames whichhave had wooden casements insertedduring this period.

Above left: 2-light oakframe window, late 1600sor early 1700s. Theleaded lights wereprobably replaced in the1800s. Zinc glazing barsand rebates have beenadded to support theglass.

Above right: 3-lightsoftwood window withmullions, mid-1800s

Left: classicallyproportioned mullion andtransom window, late1600s. Leaded lightshave been replaced withwooden casements

Left:2-lightwoodencasementwindowwithoutmullions,mid 1800s

1800 1900

5.

6.

7.

8.

9.

10.

Cast iron windows started to bemanufactured at the end of the 1700sand continued in use throughout the1800s. Although the majority of thesewere used in industrial buildings thereare occasional examples of cast ironcasement windows in houses.

During the 1920s and 30s the firm W FCrittall first produced casement windowsmade from hot-rolled steel sections.Widely used by the pioneering architectsof the Modern Movement these windowswere in keeping with the vogue forhealthy outdoor living which sweptEurope in the 1930s. Their use in newhousing and as replacements in existingbuildings became widespread duringthis period and they remained popularwell into the 1960s. They can still beobtained from specialist manufacturers.

Proportions and arrangement oflights

In smaller houses from the 1600s to themid-1800s the characteristic casementwindow was square or a horizontalrectangle divided into two or three lights,with or without mullions.

Opening casements and fixed lightswere usually sub-divided by glazing barsinto a number of panes. As techniquesfor making window glass developedthrough the 1700s and 1800s panesizes tended to increase. In earlierwindows the lights might be divided intosix, eight or even more panes, accordingto the size of the opening. Lights in laterwindows might typically be divided intotwo or three panes.

Vertical sliding sash windows

Vertical sliding sash windows wereintroduced from the Low Countries in thelate 1600s and took the place of mullionand transom windows in high statusclassical facades. The fashion quicklyspread to more humble buildings andsash windows continued to be used inall types of building until the early 1900s.Although the basic mechanism of sash

Above right:industrial pattern castiron window with acentre pivotedopening section, late1800s. Earlierwindows of this typetend to have smallerpanes.

Below left: cast ironlattice window with aside hung casementand friction stay, mid1800s

Right:steel casementwindows, probably1930s

Far right: verticalsliding sash window,about 1720. Early sashwindows, which areare often made of oak,have thick glazing barsand exposed pulleyboxes. Note the recessfor external shutters

windows remained the same during thisperiod, some details evolved as fashionschanged and as glass became availablein larger sizes. These details can helpto date sash windows and have asignificant effect on their appearance.

Vertical sliding sash windows consist oftwo glazed sections or sashes whichslide in recesses in box frames whichhouse lead or cast iron counterbalanceweights. The weights are attached tothe sashes by cords or, in the case ofvery large windows, chains. In earlyexamples the upper sash is sometimesfixed or held by wedges with only thelower sash balanced by weights.

Sashes dating from the late 1600s orearly 1700s usually have thick glazingbars (unless the sashes have beenreplaced) and exposed box frames.From the late 1700s until the mid 1800sthe fashion was for larger panes of glassand thinner glazing bars. During this

period the ‘six-over-six’ type windows(with six panes of glass in each sash)became commonplace and sash boxeswere often recessed and concealedbehind the walling leaving only a thinstrip of wood visible on each side.From about the 1860s larger and thickerpanes of glass were used in sashwindows. With heavier glass and fewerglazing bars ‘horns’ were introduced inupper sashes to increase the strength ofthe joints between the meeting rail andstiles. The existence or otherwise ofhorned sashes gives a helpful clueabout the age of a window.

Proportions and arrangement oflights

Sash windows were particularly suited tothe vertical window shape characteristicof classical styles of architecture. Thebasic proportion for window openingswas the ‘double square’ i.e. the heightbeing twice the breadth. However, thisrule was not always strictly adhered to,particularly in vernacular buildings. Amethod for determining the idealproportions of individual window panesis shown opposite Although this methodwas not always followed, the shape ofwindow panes is usually a verticalrectangle.

The proportions of the window panesand openings determined thearrangement of lights. The usual patternuntil the end of the 19th century was forboth the upper and lower sashes to bedivided into three, four, six (three-over-three) or sometimes eight (four-over-four) lights although other arrangementsare sometimes seen. From the end ofthe 19th century larger panes of glasswere available and it was common forupper and lower sashes to be dividedinto two lights each.

Where a large square or horizontalrectangular opening was wanted a‘tripartite’ window could be used. Thisconsisted of a central sash windowflanked by two narrow sidelights.

Above: vertical sliding sash window,about 1820. The glazing bars andmeeting rails are very thin and the pullyboxes are concealed behind the brickwork

Above: vertical slidingsash window, about1890. Note large panesof glass. Inset: ‘horns’ tostrengthen joint

Below: determining ‘ideal’proportions for windowpane

Horizontal sliding sash windows

Horizontal sliding sash windows usuallyhave one fixed and one horizontallysliding sash and are the ‘poor relations’of vertical sliding sash windows. As thesashes do not need to be counter-balanced by weights and pulleys thistype of window was easier and cheaperto make. Its proportions made itparticularly suitable for the square orhorizontal rectangular window shapeoften found in buildings lower down thesocial scale and in the less importantparts of higher statusbuildings.

Glazing bars

The thickness of timber glazing barswas gradually reduced from over 25mmin the early 18th century to about 12 mmby the early 19th century when, havingbecome almost too thin for stability, theywere sometimes replaced with cast ironor copper in larger windows. Goodquality and inexpensive sheet glass inlarge sizes became available from about1840 and meant that fewer glazing barswere required or that they could beomitted altogether. Sheet glass isheavier and thicker than crown orcylinder glass so glazing bars tended tobecome thicker again at this time.

Glazing bar profiles ranged from plainand simple to elaborately mouldedaccording to the status of the roomwhich the window served. In 18th andearly 19 th century houses it is notuncommon to find two or three differentprofiles used in the same building with,for example, plain glazing bars inservice rooms and servants quartersand moulded ones in reception rooms.

Window ironmongery

Original ironmongery such as hinges,fasteners, stays and counterbalancingmechanisms contribute to the characterand interest of a window.

Shutters

Wooden shutters were sometimesprovided, either internally or externally,for security, privacy and warmth.External shutters, either of board orpanelled construction, fold flat againstthe wall beside the window opening.Sometimes the presence of a recess/rebate in the face of a window frame,usually at ground floor level, indicatesthat there were once external shutters.

Internal wooden shutters were popularin the C18 and C19 and were oftenarranged to fold away into boxes eitherside of the window. Sometimes internalshutters were hung on counterbalancedcords, like sashes, and slid vertically intoa compartment beneath the window.

Every effort should be made to retainexisting shutters and associatedironmongery.

Above: horizontalsliding sash window,about 1840

Left: iron casement fastener, probablylate 1600s

(temporary)

Above: externalshutters, early1700s. Thewindow sasheswere replaced inabout 1880.

Left: internalfolding shutters,about 1725

Thick, early 18th century type

Thin, late 18th century type

Ovolo and fillet

Bevelled or ‘rustic’

Lamb’s tongue

Below: typical glazingbar profiles

REPAIR OR REPLACEMENT?

Traditional windows contribute greatly tothe character and special interest of oldbuildings. They should be retained andtheir working lives extended whereverpossible. Although maintaining woodenwindows may seem burdensome, recentresearch carried out by English Heritageshows that in the long term it often costsless to regularly repair and redecorateexisting windows than it does to replacethem.

The demand for higher standards ofinsulation and draught-proofing isanother reason often given for wantingto replace windows, but there aremethods for upgrading existing windowswhich can be equally effective. Some ofthese are described in the followingsection.

The opening parts of windows oftenbecome jammed because of a build-upof paint. Distortion of the frame andmissing, worn or damaged beads can

Recognising defects

Examine windows carefully before redecoration. It is important to identify the precisenature and causes of defects so that the correct treatments can be selected.Check that opening sashes or casements are operable and that ironmongery is inworking order. Vulnerable areas should be probed with the point of a sharp knife orbradawl. Typical defects are shown below - moisture is the main enemy:

failure of joints caused by timber decay

breakdown of paintwork and putty caused by lack ofregular maintenance - this allows water to penetratecausing timber decay

deformation of window caused by structuralmovement in wall

broken sash cords

decay of base of stiles or jambs at junction with cill

decay of cill caused by water penetration afterbrekdown of paint. Water may also creep intothe joint between the timber sill and themasonry sub-sill

also cause jamming as well as rattlesand draughts. Sash cords may becomebrittle with age or rot and break; windowironmongery, including hinges, pulleysand fasteners, may not operate properlyif it is worn or corroded. Dealing withthese kinds of defects is relativelysimple and well within the scope of thecompetent do-it-yourselfer.

Water penetration and the resultingfungal decay of timber can cause moreserious problems. Sills and the lowerparts of frames, casements and sashesare often affected. However, a skilledjoiner will be able to cut out the rottentimber and splice in replacementsections. If the damage is moreextensive the replacement of a completesash or casement may be justified butthis is better than replacing the entirewindow.

There are many examples of traditionalwooden windows in North Shropshirewhich are over 100 years old. They arestill serviceable and will remain so ifregularly maintained.

METHODS OF REPAIR ANDUPGRADING

Overhauling timber windows

The purpose of overhauling timberwindows is to correct defects caused bygeneral wear and tear. Typically, worksinclude -

• freeing jammed casements orsashes and removing build-ups ofpaint which interfere with theiroperation;

• replacing broken sash cords andlubricating pulleys;

• replacing broken glass anddefective putties (panes of antiqueglass which are cracked but notadmitting rainwater should not bereplaced);

• cleaning and repairingironmongery to leave in workingorder and replacing missing items;

• easing sticking sashes andcasements;

• replacing missing or worn beads;

• preparation of previously paintedsurfaces and redecoration.

Repairing wooden windows

The purpose of repair is to replace orreinforce elements which have decayedto the extent that they can no longerfunction as intended. The basicprinciple governing repair is that theworks carried out should be theminimum required to correct the defect.

Wherever possible, repairs to windowframes should be carried out in situparticularly when the frame is built inand cannot be easily removed withoutdamaging either the window or thesurrounding wall. Sashes andcasements can usually be removedwithout damage for repair either on siteor in the joiner’s workshop.

Where several windows have to be Ifdismantled in the course of repair, it isimportant always to mark and record theidentity of the components beforedismantling.

Spliced repairs

Spliced repairs should be made bycutting out rotten wood and piecing-intimber inserts which are shaped toobtain the maximum strength and tomatch the existing profiles. The newtimber should always be worked to theline of the existing and should follow

any existing deformations in the line ofthe window. Excessive trimming of theexisting timber should be avoided.Where possible, spliced repairs shouldbe designed so that water is directedtowards the outer face of the timber andcannot lie on or enter the repair joint.

Inserts should be made from goodquality timber of similar species andmoisture content to the parent timberand fitted with the grain orientated tomatch the existing. This reduces therisk of the insert and the parent timbermoving at different rates during dampand dry conditions which could causefailure of the repair joint or splitting. Aswith all joinery work, timber with defectssuch as shakes, resin pockets, knots,

I

heartwood or sapwood should beavoided for use in repairs. Modernsoftwood has poor inherent resistanceto decay and should be double-vacuumimpregnated with preservative by thesupplier.

Inserts should be glued with a suitableexterior grade adhesive and screwed orpinned with brass or stainless steelfixings, ideally from the inner face of thewindow.

Loose joints

Loose joints in otherwise sound joineryshould be reassembled, glued andwedged or dowelled as appropriate.

Fungal decay

Treatment of fungal decay in windowsshould generally follow therecommendations of the BuildingResearch Establishment:-

• Locate and eliminate the sourcesof moisture

• Promote rapid drying of theaffected area

• Remove decayed timber as far asis necessary to carry out repairs

• Treat remaining timber which maybe at risk with preservative

Saving historic glazing

Many windows retain original hand-made crown or cylinder glass. Crownand cylinder glass windowpanes arevery thin - typically 1.5 – 2 mm – highlypolished and, unlike panes of modernfloat glass, are not perfectly flat. Thisproduces brilliant, distorted reflectionswhich contribute greatly to theappearance of a building.Crown and cylinder glass can beidentified by looking at the shadows castby the panes on a flat surface when thesun shines through them.

These types of glass are now virtuallyunobtainable and every effort should bemade to retain panes of antique glasseven if they are cracked. Because thepanes are thin and fragile problemsarise when they have to be removed toallow repairs to casements or sashes tobe carried out. Old putty can besoftened by prolonged and repeatedapplications of solvent-based paintremover (e.g. “Nitromors”). A better wayis to use an infrared heat strip lampspecially designed for this purpose.

Replacement crown and cylinderglasses are available from a specialistsupplier but they are very expensive.Horticultural quality glass cansometimes be used as a substitute withthe agreement of the ConservationOfficer. It is thicker and heavier socounterbalance weights in sashwindows may have to be adjusted.

Reglazing in timber sashes orcasements should always be carried outusing linseed oil putty.

Weathering the window/walljuction

Traditionally the junction between thewindow frame and wall was filled withhaired lime mortar. Modern masticsealants should only be used wherethey can be applied unobtrusively (e.g.behind a planted moulding). Aerosolfoam fillers should never be used asthese are unsightly and can trapmoisture. If frames have been removedfor repair it may be possible to insert adamp proof membrane or a proprietaryfungicide impregnated building paper toisolate the frame from the masonry.

UPGRADING THEPERFORMANCE OF OLDWINDOWS

Stopping draughts and rattles

Old windows are often criticised forbeing draughty and rattling and this is areason commonly given for wanting toreplace them. However, theperformance of old windows can beimproved significantly by carrying outrepairs and installing draft seals. A widerange of seals is available which can befitted unobtrusively to both casementand sash windows. A number ofcompanies offer a nation-wide repairand upgrading service for wood andmetal windows. Gaskets, seals andother draftproofing components canalso be purchased for DIY installation.Good quality draftstrips can last formore than 20 years provided they arenot painted over.

Studies carried out by English Heritagehave shown that the cost of repairingand upgrading windows is significantlyless than replacing them and thefinancial investment is quicklycompensated for in terms of energysaving, comfort, and noise and dustexclusion.

Right: A specialistinfrared lamp beingused to soften oldputty. Radiant heat isabsorbed by the puttybut passes through theglass which remainsrelatively cool and doesnot crack. Oncesoftened by heatingputty can be carefulltyremoved

Above: Distorted andbrilliant reflectionsare characteristic ofhandmade crown andcylinder glass.

Timber windows, if properly maintained,can last for over 50 years and after thattime can be overhauled. There aremany examples of traditional woodenwindows in North Shropshire which areover 100 years old and still serviceable.

Double glazing

Installing double-glazing has been oneof the most fashionable homeimprovements over the past 20 years.However, in old buildings it is rarelyeconomical and studies by EnglishHeritage have shown that it can take atleast 60 years for energy savings tocover the cost of double-glazing.

It is seldom possible to install sealeddouble glazed units into old casementsand sashes as the glazing rebates areusually too shallow, particularly inwindows with very fine glazing bars. Ifdouble-glazing is required it should be inthe form of secondary glazing.Secondary glazing is relatively easy toinstall and can be reasonablyunobtrusive if the divisions in thesecondary glazed panels correspondwith those in the window itself.

Windows with internal shutters are notusually capable of being secondaryglazed but if the shutters can be used orheavy curtains provided the need fordouble-glazing is significantly reduced.

REPLACEMENT WINDOWS

Design and materials

An existing traditional window shouldonly be replaced after it has beenagreed with the Conservation Officerthat it is truly beyond practical repair.The replacement window should matchthe form, detailing and operation of theoriginal window in all respects. It will benecessary for the maker of the new

Above: draught sealsfor sash windows(from “Draught-proofing andsecondary glazing”English Heritage“Framing Opinions”Leaflet 1)

Left: Brush typedraught seal in sashwindow

window to accurately copy the profilesof all the window components includinghead, jambs and cill of the frame andthe stiles, rails and glazing bars of thesashes or casements. Old glass shouldbe carefully salvaged and reused.Where practicable ironmongery shouldalso be overhauled and reused.

Counterbalancing springs should not beused in replacement sliding sashwindows as a substitute for pulleys andweights as this significantly alters thedetailing and appearance of the window.

New leaded lights should always bemade in the traditional manner. Stripsof lead stuck over a single sheet ofglass look nothing like the real thing andis not an acceptable substitute.

Where an historically inappropriatewindow is to be replaced the newwindow must be carefully designed anddetailed to be in keeping with the periodand architectural style of the building. Itmay be possible to base the design onold windows which survive elsewhere inthe building or it may be necessary to

look for examples in other buildings ofthe same style and period. TheConservation Officer will be happy toadvise you and can provide you withdetailed drawings of typical types oftraditional windows.

Above: Historicallyinappropriate windowsin an early 19thcentury terreacedhouse.

Above right: Detailedworking drawing forreplacement windows.The design and detailshave been taken fromsurviving originalwindows in the sameterrace.

Right: Appropriatewindows reinstated.

It is important to remember that modernsoftwoods are far less durable thanthose used in the past. Replacementsoftwood windows should therefore betreated with preservative before paintingusing a double vacuum impregnationsystem (“Vac-Vac”). When hardwood isused for cills or for complete windows itimportant to ensure that a durablespecies such as English oak or iroko isspecified. Many types of hardwoodsused in the joinery trade are no moredurable than softwood (e.g. meranti)

PVCu windows

The appearance and character of PVCuwindows always makes them unsuitablefor use as replacements in ListedBuildings and in Conservation Areas.PVCu windows are assembled fromfactory-made components designed forrigidity, thermal performance and easeof production. Their design, detailing

and operation make them lookcompletely different to traditional timberwindows.

In addition, there are significantenvironmental and human healthhazards associated with themanufacture, use and disposal of PVCproducts.

Far left: Traditionaltimber vertical slidingsash window. Note theslender glazing bars,narrow meeting railsand the similarlyproportioned panes ofglass. Compare thiswith-

Left: a PVCureplacement window.Framing componentsare disproportionatelyfat and unmoulded;glazing bars aredummies inside thedouble-glazed units.

An argument often used in favour ofPVCu windows is that they require nomaintenance. Recent research carriedout by Building magazine indicates thatthe long-term maintenance costs ofPVCu are only about 25% less than forsoftwood windows. Exposed plasticsurfaces become dull and discolouredafter a time and special paints are nowproduced to re-decorate weatheredPVCu. It will also be necessary toreplace gaskets and seals during thelifetime of the window.

PAINTING WINDOWS

With the exception of early unpaintedoak-framed windows, traditionalwindows were always painted to protectthe timber and for aesthetic reasons. Ifpaintwork is allowed to deteriorate it isnot only the appearance of the windowswhich suffers; water pentrating the paintfilm can cause the underlying timber to

decay. Putty also becomes brittle andprone to cracking after a time. Theseproblems are best avoided by regularinspection and redecoration of thepainted surfaces.

Modern timber windows are oftencoated with wood stains. However, theappearance and character of this typeof finish make it unsuitable for use on

traditional joinery in listed buildings andconservation areas. High performancepaints designed specifically for use onexterior woodwork are now widelyavailable and are more durable thangeneral purpose house paints.

DO I NEED PERMISSION?

Listed building consent

Listed building consent is required toalter the design, material or colour of anywindows in a listed building. If windowrepair or replacement is beingconsidered please consult theConservation Section, Planning ServicesDepartment at North Shropshire DistrictCouncil as soon as possible beforeundertaking any works.

Planning permission

Planning permission is normally requiredto alter windows in all buildings which arenot single dwelling houses. Planningpermission is also required to alterwindows in a single dwelling house if it isin a conservation area where an“Article 4 Direction” has been made.The Planning Services Department willadvise you if you need to apply forplanning permission and/or listed buildingconsent. Please check before carryingout any works.

Building regulations

Approval under the Building Regulationsmust be obtained for replacementwindows. To comply with the BuildingRegulations replacement windows mayhave to incorporate features, such asegress hinges, double glazing and trickleventilation, which can affect theappearance and character of traditionalwindows. The visual impact of thesefeatures can be minimised by carefuldesign and detailing. In listed buildings amore flexible approach to meetingBuilding Regulation requirements ispermitted so that the appearance oforiginal windows need not be altered.

WHERE TO GET ADVICEAND INFORMATION

Advice

Practical advice on all aspects of buildingconservation is available from theConservation Section, Planning ServicesDepartment at North Shropshire DistrictCouncil. Tel 01939 238433 or 238434.

For advice about the BuildingRegulations please contact the BuildingControl Section at North ShropshireDistrict Council. Tel 01939 238423.

Useful publications

Living and working with old buildings inNorth Shropshire.North Shropshire District Council.Tel 01939 238429www.northshropshiredc.gov.uk

Andrew Townsend and Martyn Clarke.Repair of wood windows. Technicalpamphlet 13.Society for the Protection of AncientBuildings, 37 Spital Square, London E16DY.Tel 0207 377 1644.www.spab.org.uk

Framing Opinions leaflets.English Heritage, 23 Savile Row, LondonW1X 1AB.Tel 0207 973 3000.www.english-heritage.org.uk

The Georgian Group Guides:No1 Windows.The Georgian Group, 6 Fitzroy Square,London W1T 5DX.Tel 0207 377 1644.www.georgiangroup.org.uk

Care for Victorian Houses: No 9 TimberWindows.The Victorian Society, 1 Priory Gardens,Bedford Park, London W4 1TT.Tel 0870 774 3698.www.victorian-society.org.uk