A view of the Innovation park Photo: Photo: Peter White/BRE
A house to call a home
Rosemary Hartill looks at eco-friendly developments in the market for new-build houses
What sort of house would you really like as your future home? One with minimal heating bills, airtight and with controlled ventilation? Made of responsibly sourced sustainable materials? With good day lighting, sound insulation and rainwater harvesting? Adjustable to changing living patterns? The challenge currently facing the building industry is how to turn that dream into reality. In a normal house built to today’s building regulations, the average area of air leakage is about a square metre. By 2016, leakage allowed will be reduced to the size of a business card. Government regulations say that by that year (certainly by 2020) every newly built home should have a net zero carbon footprint – that means almost no energy bills at all. No wonder that the recent eco-build fair at Earls Court Exhibition Centre was packed out with thousands of people in the building and design industry searching for effective and practical new eco-concepts, developments, products and materials. They ranged from straw-bale building blocks, to wallpaper that emits light, to water-saving taps turned on by waving a hand, to porous paving made of shredded recycled aircraft tyres. But which ideas are really cost-effective? Which really work? And what might an eco-house built with the latest ideas actually look like?
At the Building Research Establishment (BRE) Innovation Park at Watford, six prototype eco-houses and a model health centre are being rigorously and scientifically tested for efficiency and practicality. Two more eco-homes will open soon. Officially opened in June 2005 by John Prescott, then deputy prime minister, the park has attracted over 20,000 visitors.
The best known eco-house on display is the three-storey Barratt Green House, which won the 2007 Home for the Future Design Award run by the Mail on Sunday. To reach the zero carbon level, it includes triple glazed windows, large areas of photovoltaic and solar thermal panels, computerised window shutters, and a 3000-litre underground tank.
Its design, with striking board and copper cladding, balcony, internal gallery and flexible layout, is particularly popular with younger people. The prototype is said to have cost £1.2 million. The wood and metal staircase alone is rumoured to have cost £40,000.
More practical for social housing is the three-bedroom Renewable House, which can be built for only £75,000, excluding the cost of land, groundworks and installing utilities. Low carbon rather than zero carbon, with heating costs between only £150 and £250 a year, it’s built with a timber frame and hemcrete walls – hemcrete is a mix of hemp and lime mortar. As demand for rape crops diminishes, hemp could become a licensed alternative non-food crop for farmers.
This house is built for ‘lifetime’ living. In other words, it is flexible to changing needs. Given the ageing of our population, the care system is likely to be under increasing pressure, and more and more of us may have to remain in our own homes. This house has a staircase wide enough to install a stair lift, and a space large enough to install a wheelchair lift at a later date.
Arguably, the most exciting internal (and least boxy) design displayed is the Hanson Eco-house, whose open-plan first floor, rising to a ventilating kiln-shaped roof lantern, creates a glorious light-filled living space. It is not currently available in kit form.
Inspirational as the ideas in the Innovation Park are, questions abound. I found myself wondering how I could open that high window? Or reach that high lightbulb? Was a gallery really a sensible design, given children’s delight in throwing things over? Could the technology controls be made simpler? Was the water-saving washing machine really big enough for a family load?
But the really significant question marks are about the capacity of the UK building trade and customer communication. The tight specifications of a new eco-house need precise work. BRE’s training courses have taken up the challenge of ‘turning white van men into green van men’, as they cheerfully put it. But in the meantime, the Scandinavians and Germans are rather further ahead.
Another improvement for the customer would be kite-mark-approved materials and eco-builders. Also, an official body overseeing the issuing of post-production certificates confirming what level of sustainability a new eco-home has achieved.
The search is clearly on for greater simplicity as well as sustainability. The Renewable House’s simple design avoids the costly ‘eco-bling’ of some of the other houses – like the solar thermal, photovoltaic and micro-wind technologies. Micro-wind turbines don’t always perform that well in urban environments like Watford. However, recent changes in energy rates make selling spare electricity to the national grid more cost-effective.
Other approaches cut costs by eliminating corridors, or by a single core central service unit providing kitchen, bathroom, electricity and other services.
Later this year, another simpler eco-house, The Natural House, is to open at Watford. Developed by the Prince’s Trust for the Built Environment, and in a more traditional style, it relies on natural materials either grown or taken from the ground. Its low-energy structure is aerated clay blocks with lime-based plasters and renders.
Lessons learned through these prototypes and other experiments are filtering down to the building trade and to the eco-towns that the government is commissioning.
But given the present gulf between theory and practice, and between inspirational show buildings and consumer cost-effectiveness, it’s hard to believe that in a mere six years every new build will be able to say goodbye to energy bills.
Visit www.bre.co.uk to learn more about the BRE innovation park.
