Published in The Scotsman, 20 December 2008
If you travel to Unst in Shetland you may come across a worldwide eco-phenomenon. A self built zero-carbon house has been built on this remote, windy island.
It has been designed, constructed and powered to minimise its impact on the environment. Even the food eaten by its residents is considered.
The story of the zero-carbon house is being followed by thousands of people, some of them very influential.
It is the brainchild and retirement project of an English couple, Michael and Dorothy Rea, who moved to Unst in 2002.
Initially, the idea had a mixed reception from the community, according to Mrs Rea: “People found it difficult to grasp what was being planned, and reserved judgement,” she recalled.
The house is timber framed and clad, using wood from sustainable forests. Soil, paving slabs and stones were reclaimed where possible. Mrs Rea said: “We built using the traditions of a croft house, upgraded to the 21st century. We wanted it to be harmonious in its surroundings yet instantly recognisable.”
There was no precedent, so a team of experts from around the world was assembled from scratch.
The challenges, including travel distances and weather, were significant. Red tape was an issue too. “So new were the ideas and concepts to planners that it took three and a half years to obtain permissions and warrants,” Mr Rea said.
Building was painstakingly planned, but swift. “Four men, put up our frame up in four and a half days in strong gales,” Mr Rea said. This was the only time outside contractors were used during its construction. Local plasterers, plumbers, electricians and roofers were used. Mr Rea did much of the labouring.
Key to the success of the house is its extraordinary insulation, which keeps heating to a minimum. An air source heat pump feeds warm water to an adapted tank, which works an underfloor system.
The building cost just over £ 200,000. Sponsorship came from the Scottish government, a bank, and an incredible 35 businesses and organisations keen to promote their building and energy efficiency products.
The couple moved in last January. “It is far better than I expected,” said Mrs Rea. “With an open plan design and many windows taking the sun, it is very warm.”
After almost a year in the house, the Reas have learnt vital energy facts for the next phase. In spring, a wind turbine will be installed to meet all electricity needs. On a windy day (Force 10 gales are common in Shetland), this will generate more than the house’s entire monthly requirement of 95 kilowatt hours. Additional power will heat the greenhouse and supply neighbours. This will avoid the emission of five tonnes of CO2 a year.
Fresh food, particularly fruit and vegetables, is in short supply on Shetland, with only one weekly delivery from the mainland. Mr and Mrs Rea aim to grow as much as possible, and provide what they do not eat to the community.
A high-tech greenhouse, with hydroponic growing system and LED lights for the winter months, will be installed. Aubergines, peppers, runner beans, raspberries and strawberries are being considered.
Perhaps the greatest environmental benefit is the house’s ability to inspire others. “We are helping people look at how they can install heat pumps and keep greenhouses warm using wind power,” said Mr Rea. A secondary school is using the house as an case study, helped by Mrs Rea.
Academics at the University of Dundee and the Scottish Crop Research Institute are in touch about energy and growing food hydroponically, and 13 postgraduate students are using the zero carbon house for their research.
Its example has created media interest worldwide.
Hundreds of emails have been received. The Chinese and Canadian governments are watching progress.
A leading green energy company plans to distribute a book about the project to millions of customers. The toy company, Hasbro, wants the house to feature in its new “Game of Life”.
The Reas are considering B&B as well as their energy and food projects. But it could go further. As Mrs Rea said, “Watch this space.”

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