Cousin to the dagga plant, hemp has101 uses – and could even prove

to be the perfect greenbuilding material!

The house thathemp built

By Beatrice Moore-Nöthnageland Shelly Bergh

Photographs: Francois Oberholster

Linear and contemporary,this ecofriendly houseappears larger thanits 187m².

LEFT Proud homeownerTony Budden.

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Practically everythingin the house isfrom a renewable orsustainable resource,from the hemp carpets(from Coirtex) to thecork floors and anashwood staircase. >>

If you thought hemp was just anotherword for marijuana, think again.While the two are related, it’s how they’re

cultivated that sets them apart. And notonly does hemp contain minimal THC – thepsychoactive compound found in marijuana– but it is also as incredibly versatile asbamboo, if not more so. With the soft,durable fibres of the Cannabis sativa plantyou can make anything from carpets,curtains and clothes to beauty and foodproducts such as hemp seed oil; the seedsare rich in omega 3, 6 and 9 fatty acids.You can even build a house with it.This is exactly what Tony Budden and

Duncan Parker of Hemporium did inNoordhoek, Cape Town, along with Erwinvan der Weerd of Perfect Places. Theywanted to prove that hemp is a successfulalternative building material and that youcan move away from mined materials andsynthetic materials to renewable resources.Apart from hemp, several other building

methods were used to ensure the house isas ecofriendly as possible.

StructuralsignificanceThe structure is completely modular – allthe panels are made in a factory withintwo-and-a-half weeks and brought to thesite to be put together. The walls consistof four layers: the outer part is made ofmagnesium oxide (mgo) panels, followed bya breathable foil membrane and a doublelayer of hemp insulation – hemp particleboard panels were used inside. ‘Ironically,the magnesium oxide comes from SouthAfrica, is exported to China to be processedand then the completed mgo panels arebought back! We really hope this practicewill be stopped in future,’ remarks Tony.Some of the walls have been built with

‘hempcrete’ – a natural cement madefrom the stalk of the plant and lime. Thewalls are ‘carbon negative’ and moreenvironmentally friendly than conventionalbuilding materials like brick and cement.And though they’re barely 20cm thick,

the walls breathe – so they keep cool insummer and warm in winter.Painted in a durable, water-resistant

non-toxic paint from B-earth, the wallsonly have to be repainted every four tofive years, as opposed to other ecofriendly

The house cost about R7 500/m² to build; R10 500/m² with finishes,which compares favourably with building costs in Tony’s neighbourhoodof about R12 000 to R15 000/m². Yet it was not intended to be a low costproject. ‘Building was quite stressful at times because our local builderswere not familiar with this method,’ says Tony. Fortunately, he hadregular email consultations with the experts he met at the InternationalHemp Building Symposium in Ireland two years ago.

Serious savings

Hemp predominates in thelounge: the built-in sofa ismade of hemp fibreboardwith a veneer layer and thecurtains and scatter coversare made of hemp material– as is the artwork!

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paints that have to be repainted annually.As the roof is flat, a special scaffold had to

be installed to accommodate the solar geyser.And a vygie garden on the roof also addsfurther to energy consumption savings.

The interior wallsThe interior walls were finished with a layerof hemp screed. This mixture, consisting ofchipped pieces of hemp stalk mixed withlime and sand, has thermal and humidityproperties that ensure it’s not nearly as coldas a cement wall. ‘Our electricity bill was onlyR450 per month in winter, as only one wall-mounted heater was necessary to heat thewhole house,’ says Tony who shares the housewith his partner Melanie Ravot. Other wallswere painted with paint from B-earth and asthe hemp screed is not suitable for kitchensand bathrooms, tiles were used there.

InnovativeviewpointsThe double-glazed windows are filled with gasthat prevents heat from escaping. ‘Initially itwas a big expense, but you definitely saveenergy with time,’ says Tony. In addition, thewindows are automated with a thermostat andthe temperature is regulated by opening thewindows on the cooler or warmer part of thehouse; this system was installed by Green WindPower Automation.

Floor finishesCork flooring was a logical choice because corkis a sustainable renewable source as only thestem is harvested. Cork is extremely durable,soft and anti-allergenic and has excellentinsulating properties. But as it has to beimported, the carbon footprint is quite high.

Light on trackAll the light bulbs in the house are energy-saving LED bulbs supplied by Earth Power.Large windows on the south side ensure abeautiful view of the Noordhoek beach whilesmall windows were used on the north side. >>

How doeshemp work?Insulation mats aremade of the stronglong hollow fibresof the hemp stalk(1), while the restof the chipped stalkis mixed with limeto make bricks (2)or compressed intoparticle boards (3and 4). The shavingsare also mixed with alime-based binder touse as screed.

2

3

4

1

Old Oregon pine ceiling panels were reusedas cupboards and sealed with a non-toxicproduct from B-earth to preserve their naturallook. The recycled counters are from Cannata,the hemp chandelier is from Moonbasket andthe tablecloth from Hemporium.

After muchdeliberation, good oldSA pine was used forthe deck as it’s not onthe endangered list.

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• Do not pressure yourself to be 100% green.Use what you have rather than not trying at all.As the industry grows, we will have more optionsand the costs will decrease.• Sustainability is more important thansimply following an ecofriendly trend – useenvironmentally friendly paint that has to bereapplied every three to five years rather than one

that has to be applied annually – it will cost you fivetimes more and uses more energy to manufacture.• The most sustainable thing you can do in yourhouse is to insulate it. About 20% of a home's heator coolness is lost through the roof.• Choose double glass for your windows.• Wood panels for interior walls will assist withinsulation and can be added later.

Tony and Erwin’s green tips

The bed is made ofbamboo and all thebedding, of hemp.

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The future of hemp‘More and more, hemp is being seen as the“better than zero carbon footprint” buildingmethod to consider,’ says Tony, ‘yet it is stillalmost impossible to grow commercially inSouth Africa – even though it’s being cultivatedin more than 40 countries worldwide.’All the hemp used to build this home hadto be imported from France.

The Department of Agriculture recogniseshemp as an agricultural crop, but legallythere is still no distinction between dagga andindustrial hemp. However, efforts are beingmade to have legislation amended in order tocreate a hemp industry. Hemp can be grownand harvested within four to five months; seedscan be harvested in six months. This is anannual plant and it uses a rotation system.No pesticides are used and it is only fertilisedonce. Hemp can be used as a renewablesource for paper, fuel, textiles, buildingmaterials, food, beauty products and more.

Tony’s study (above) havehemp particle boards veneeredwith a thin layer of wood onthe wools, ideal for insulation.The bath (below) is clad inbamboo, enhanced by water-saving fittings from Hansgrohe.

Great greencontacts

• Hemporium 021 762 4380,hemporium.com for hemp fabricand products.• Perfect Places 0861 002 025,perfect-places.co.za for modularecofriendly houses.• B-earth 079 900 0218,b-earth.co.za for ecofriendly paintsand sealers.• Massclusivity 076 290 7120,dgglass.co.za for double glasswindows.• Green Wind Power & Automation072 479 4215, greenwind.co.zafor automated windows.• Coirtex 021 762 2227,coirtex.co.za for hemp rugs.• Cannata 021 510 8553,cannatagranite.com for recycledkitchens and countertops.

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