The Barratt Green House

In 2007, via Gaunt Francis, we entered a national competition with a radical proposition: that a genuinely zero-carbon family home could be solidly constructed, stylish, modern, and replicable. The scheme won — with 22,000 public votes — and the prize was to build the design. In stepped Barratt, and the hard work to translate innovation into a housing first began!

The Competition

The National Centre for Excellence in Housing, working with the Mail on Sunday and NHBC, launched a competition in early 2007 to design a "Home for the Future" — one that could realistically be delivered by a volume housebuilder. Thirty-five practices entered. A panel led by Michael Manser, past President of RIBA, shortlisted nine designs on the basis of aesthetics, buildability, sustainability approach, and public appeal.

The shortlisted nine were then put to a public vote through the Mail on Sunday and the Think 07 sustainability exhibition. The Gaunt Francis design received 22,000 votes. Barratt Developments — one of the UK's largest housebuilders — was subsequently engaged by the National Centre to build the winning design as a full prototype at the BRE's headquarters at Garston, near Watford.

The design set out to prove that sustainability could be mainstream — not a niche aspiration, but something a volume housebuilder could build at scale, without it looking like a statement.

The Design

The Green House is a three-storey, three/four-bedroom family home. It includes a through living-dining-kitchen space, a games and play room, home office, family bathroom, and ensuite to the main bedroom. All rooms are generously proportioned and served from a central hallway, which runs from the front door and covered carport through to an external terrace at second-floor level.

During the pre-construction phase, the target was raised from the original competition brief to Code for Sustainable Homes Level 6 — the maximum, meaning zero net carbon emissions from operation across a full year. It also achieved the Treasury's Stamp Duty Exemption definition of zero carbon — making it the first home by a mainstream volume housebuilder to be exempt from stamp duty on environmental grounds. The home achieved an EPC rating of A and met both Lifetime Homes and Secured by Design standards.

The external form was deliberately familiar: rendered walls and pre-patinated copper cladding gave the house a contemporary but replicable character. The design was conceived so that alternative external treatments — brick, timber, stone — could be applied to suit local vernacular, making it genuinely deployable across Barratt's regional portfolio.

Technical Performance

The structure was built from storey-height aircrete panels with thin-joint mortar and concrete floor slabs — providing a robust, high-thermal-mass frame. A continuous envelope of approximately 180mm of high-performance phenolic insulation ran from the concrete raft foundation up through the walls and into the timber SIPs butterfly roof, achieving U-values of 0.11 W/m²K or better throughout.

The decision to avoid biomass was deliberate. District heating via air-source heat pump was chosen as more replicable across the typical Barratt site, where a biomass fuel supply chain could not be guaranteed. Automated external shutters provided solar control in summer and security at night, managed by the home's building management system.

Press Coverage and Recognition

The Green House attracted national press coverage across a wide range of publications on opening in May 2008, including the Financial Times, the Daily Telegraph, the Evening Standard, the Guardian, the Daily Mail, the Mail on Sunday, Building, Building Design, the Architects' Journal, Property Week, and Showhouse. Coverage spanned both the specialist construction press and the mainstream national media, reaching a combined audience in the millions.

An article in Building magazine described the project as the second CSH Level 6 home in the UK, and the first by a volume housebuilder. Germaine Greer contributed a commentary to the Architects' Journal on the wider significance of the project. The project was also written up in the Architects' Journal in a feature accompanied by photography by Peter White.

Legacy

The Green House was conceived not as an end in itself, but as a working proof of concept. Its seven-strand legacy — as identified at the time — included: engaging the public in the real possibility of sustainable housebuilding; supporting government policy on the route to zero carbon by 2016; building the relationship between the volume housebuilder sector and the sustainability research community; generating real build experience at Barratt that could be applied to live projects; and providing a focal point for the next wave of innovation.

It demonstrated, concretely, that a family home built by one of the UK's largest housebuilders could meet the highest sustainability standard, be exempt from stamp duty, be photographed with a wide-angle lens without apology, and be something a family would actually want to live in.