A shade of residential green

Cob is a mixture of mud, sand and straw, which can be "moulded" in order to form walls, and indeed this is the material that one Romanian architect has decided to revert to. Ileana Mavrodin claims she started to build her first cob house as an experiment in 2004. Having just returned to Romania after twelve years of living in Canada, she bought the land needed for under USD 2,000 and spent the next year building her cottage. "The place was perfect for building a cob house," she explains. "It's a question of a southern exposure, with a clay sandy soil and a nearby river," she explained, adding that it is necessary to gather all the construction materials locally. Such traditional houses require no air conditioning, since they remain cool in the summer and retain their heat in the winter. Now she is helping to build similar houses throughout the country, with two under construction near Timişoara, two near Bucharest, one near Sângeorz-Băi and one near Curtea de Arge?. She urges those who want to build cob houses themselves to attend one of her seminars, where she demonstrates and explains not only traditional building techniques, but how to fill in all the required paperwork.

The Ozone player
Ozone Homes takes a very different approach. Instead of low-tech mud, the company has developed a new high-tech vegetable (canola) based building material, which Andrew Prelea, the CEO of Ozone Homes, states has proven stronger than concrete in load tests. The material is coated with Tyvek, a material developed by DuPont that allows water vapour to pass through it, but not liquid water, and so the building is able to breathe. Apartments built with this material require around 50 pct less energy to heat - providing the building is used correctly. The first such project, the Avalon residence in Pipera-Tunari, was completed in 2011 and offers a useable area of 840 sqm with 12 apartments. Andrew Prelea tells the story of one apartment owner who failed to realise the benefits of such insulation, because he left the windows wide open during one of the coldest winters on record in the country (with temperatures around -20?C). However, his neighbour in the same block kept his windows closed, set his thermostat to 23?C and paid no more than EUR 30 per month. "Everyone would like to buy a green home providing it doesn't cost more money," says Mr Prelea, when he was questioned about the demand for ecological homes and he claims Ozone can build such homes cheaper than more traditional builders. He explains that everything in Ozone's pre-fabricated design fits together "plumb square", resulting in almost no wastage and that almost all the materials used are recyclable. The company is soon to sign a contract with the ministry of defence to provide housing for servicemen (both serving and retired). Around 2,000 apartments could eventually be built around the country.

Here comes the sun
Prispa's Solar House lies somewhere between these high-tech and low-tech extremes. The designers have chosen only tried and tested solutions, but have managed to design a home that produces more electricity than it uses. "Traditional builders in Romania use a lot of passive strategies for energy conservation, which are quite underrated," claims Alexandra Petraru, the communication coordinator for the project. "What we tried to do was to build a house for under EUR 70,000 so that it qualified for the government's Prima Casa (first home) programme." The house produces around 9,501 kwh, while using app. 7,349 kwh per year. Unfortunately, most of this electricity is produced during the summer and consumed during the winter and there is no possibility in Romania of selling the excess back to the grid. The project was developed for the Solar Decathlon contest in Madrid, which was held in September 2012. The project is open source and, according to Alexandra Petraru, people in Spain are now building similar houses.

Alex Hayes