An Eco-Friendly Self Build

It took just two hours to demolish the home Peter and Mhairi Taylor and their two sons had lived in for 17 years. But as the couple had plans to replace the 1950s chalet bungalow with something far more exciting, any feelings of nostalgia were replaced by the thrill of anticipation.

"The old house was poorly insulated and faced the wrong way anyway, so rather than spend money on it we decided to knock it down and build new - and we were keen to do it in an environmentally friendly way," explains Peter.

Located in the former grounds of a 19th century mansion house on a green belt site near Edinburgh, the Taylors' property included a small but separate lodge house, destined to be their home for the duration of the build. Living on site was particularly valuable as Peter and Mhairi were determined to manage the project themselves.

It's perhaps just as well the Taylors were living on site, as the man responsible for the design - Peter's brother-in-law and architect Lindsay Johnston - was on the other side of the world. An Irishman who studied in Scotland and now lives in Australia, Professor Johnston is internationally recognised in the field of low-energy, environmentally sustainable building design.

"We gave Lindsay our remit, which included lots of light, open spaces, and an indoor/outdoor lifestyle, and he sent back a model, along with a tape he'd recorded to explain his thinking behind the design," says Peter. He adds: "When we said we were delighted, Lindsay came over to talk in more detail and liaise with a local Edinburgh architect to submit planning etc."

Although the site is technically green belt, the project was a one-for-one replacement and on that basis, acquiring planning permission was straightforward - the only proviso being a height restriction to prevent the building overshadowing a nearby listed stone archway. It also helped that services, including sewerage, were already on site.

The design is both inspirational and deceptive: an elongated detached four bedroom bungalow with a predominantly open plan layout over three floors. From the outside, the design pays lip service to a traditional one-and-a-half storey style. But there's a contemporary twist in stainless steel gutters, dormer windows with glazed sides and flat roofs, decks that blur the distinction between the interior and the garden, and full-height windows with glass-to-glass corners, designed to maximise unobstructed views over open countryside to the Firth of Forth. Equally striking, the line of the steeply pitched roof extends to an adjoining conservatory at one end, where a doubleheight glazed ceiling incorporates photovoltaic cells to convert the sun's rays into electricity.

SIPs (structural insulated panels) construction forms the basis of Lindsay's design: a system chosen for its design flexibility, low wastage and superior insulating properties. Essentially a timber ‘sandwich' with an insulating, dense and non-permeable centre, a SIPs house can reduce heating bills by as much as 60 per cent. It's also stronger than a conventional timber frame, eliminates condensation, and, once completed, is indistinguishable from any other house.

By the time Lindsay Johnston arrived in Scotland, Peter and Mhairi were busy researching geothermal heat pumps and obtaining quotes for everything from solar panels and whole-house ventilation systems to a garden water harvester. "At the same time we were also trying to find a builder, but having approached nine companies, none were interested, mainly because the non-standard design featured long glass walls supported by a steel frame," says Peter.

When BPAC in Fife accepted the project, the couple broached the possibility of using geothermal heating. "We'd read about it in a self-build magazine and were keen to incorporate it until we heard horror stories about equipment that didn't work," he says. "Then we went skiing in Norway and met an architect who showed us a Swedish heat pump available from a UK distributor and that convinced us to go ahead."

Based on the fact that the temperature underground remains at a constant 10-13°C, geothermal heating systems are either based on pipes sunk several hundred feet into the ground linked to a heat exchanger to provide domestic hot water and feed central heating radiators (in the Taylors' case, underfloor heating), or use a ground-source heat pump and pipes laid horizontally closer to the surface to harness the sun's energy. Not having the large surface area required for the second option, the Taylors chose to sink geothermal pipes into a specially constructed borehole. "We were eligible for a grant to offset the cost of installing the solar system and ground-source heat pump, but the application process is complicated and needs to be simplified," Peter comments.

Living on site, Peter and Mhairi were hands-on from the start, clearing the ground in preparation for the concrete foundations. One contractor did the underbuild, basement, and beam and block floor, thereafter BPAC, the main contractor, took over. "There were so many decisions to make, it was never ending," says Mhairi. "In between sourcing products on the internet, going to specialist shows and exhibitions, and generally just talking to people, we cut and laid all the base insulation - 90mm thick and around 400m² of it - before the poured screed and underfloor heating could be laid. And we always made a point of tidying up the site at the end of each day, which gave us the chance to check progress."

All these things took a massive amount of energy. Mhairi and Peter also landscaped the garden themselves. "Like the house, it too evolved, depending on where the earth landed," she laughs. As the couple are keen gardeners, this challenge was one they relished, particularly as they managed to incorporate stone from their original home into the setting.

Gradually the house took shape. SIP exterior walls (1,670mm-wide panels) were strapped and sheeted with a 100mm cavity and 100mm blockwork. The roof is also SIPs, a system that doesn't require roof trusses or any other support that will reduce the amount of space. Spanish slate tiles give the roof a traditional finish. Steel framing was required in places to support vast, low-emissivity double glazed windows and sliding patio doors. "We did think about using self-cleaning glass for the atrium above the staircase, but the company needed three months to test the ceiling material and we couldn't wait that long," Peter explains. The German-designed Schüco conservatory was built by Northern Tectonics, who also installed the photovoltaic solar cells in three arrays, facing east, west and south. The electricity is sold directly to the grid, with every unit generated credited by Good Energy.

For the next three years the project became a fulltime occupation. "You do everything yourself because you know what you want," Peter reflects. "At times the builders were reluctant to try new things, but we always got there in the end. We were lucky in that we had relatively few problems overall. Some trades didn't turn up because they were too busy elsewhere, and the render company held us up for several months - but we're quite patient people really," he adds.

The Taylors' home is notable for its clean lines and a deceptively spacious interior that includes a basement, open plan ground floor with a dining hall, living room and kitchen/family room linked by huge sliding panelled doors, made from American white oak and designed by Mhairi. Upstairs are four bedrooms with coombed ceilings, and three bathrooms. Additional rooms have been worked into the design - a cloakroom off the hall, his and hers studies off the kitchen, and four stores, a washroom, laundry, plant room and hobby room, off the adjoining conservatory.

Equally impressive are the things you can't see, such as the loft-based Nuaire home ventilation system, which continuously inputs filtered fresh air from the outside. And the reams of cabling masterminded by their son Iain, a partner in Edinburgh-based Ezone Interactive (a website management system). Using ‘flood wired' cabling, which caters for every conceivable eventuality, the main AMX controller has the ability to control virtually everything, although at present it's only configured for home entertainment. Control panels in each room mean that different music can be selected as an alternative to whole-house listening. The house also has Wi-Fi internet access and wireless lighting, while three zones (basement, conservatory and living room) have been wired for home cinema. "Based on the amount of cable he bought and what he was left with, Iain recently calculated we have 7km of cabling in total," says Peter.

Most of the Taylors' other choices are more visible, including a gas-fired Aga in the kitchen, Phoenix multi-fuel stove in the living room, Philippe Starck bathroom fittings, and Caithness slate floors in the kitchen and adjoining conservatory. The couple appreciate good design but prefer simple, clean lines, and their home reflects a preference for quality over quantity.

There are some unusual features too, such as the angular staircase in the dining hall, with a clear glass balustrade and stainless steel support. "We'd initially wanted something less fussy," says Peter, "but the legalities meant it was not to be." Upstairs, the master bedroom has French doors leading onto a north-facing balcony that provides superb views of the Forth estuary, while two adjoining bedrooms at the other end of the house each have double doors out onto a shared balcony that overlooks the conservatory.

"This was a very non-standard house, so it took a long time to build and involved a lot of research. Now that we're actually living in it, we love it," says Peter. "It achieved what it set out to - it's an outside/inside house. There are cosy corners, but opened up, it can be a big hospitable space." Would they do it again? "Absolutely - but perhaps a smaller country version."

Further reading:

• Renovate or Rebuild: Which is Greener?
• A SIPs Self-build
• An Eco Friendly Riverside Home Built with SIPs