Couple share their green credentials; A couple are sharing their experience of building their own eco-home. Environment Editor Tony Henderson reports.

Byline: Tony Henderson

BUILDING their own eco-home is a juggling act for self-employed architects Duncan Roberts and Mary Kelly. "It's a question of money and time, and there is never enough of either," says Duncan, who studied architecture at Newcastle University.

The couple began building their home in West Back Lane, Belford in Northumberland eight years ago. Five years ago they had completed enough of phase one of the house to move in.

Now they have started digging the foundations for phase two - and today and tomorrow they will be welcoming visitors who can check on their progress as part of the Heritage Open Days programme in Northumberland.

For the single-storey first phase, the couple used Douglas Fir from the Borders in a post and beam structure.

This involves bolting the timber frame of the house together while flat on the ground and then hauling it upright.

Larch wood was used for the external weather boarding, and sheep wool from Cumbria was installed as insulation, while the flat roof is coated with earth and gravel and planted with sedum to compensate for the area of land the building takes up. The effectiveness of the wool insulation, triple-glazed north-facing windows and solar gain from larger south-facing windows, means the house does not need central heating.

The couple only use a pot-bellied wood stove, burning just half a tonne of wood each winter.

The completed phase consists of one bedroom, a living room, bathroom and kitchen.

The second phase will see another two bedrooms, office, kitchen-dining room, shower room, a rainwater harvesting system for flushing toilets, solar water-heating panels, and recycled paper providing the insulation.

The foundations will use limecrete - a mixture of salvaged stone and lime mortar.

Duncan and Mary must fit in their building operations with other work they undertake to pay the living bills and provide funds for the construction.

But they hope to have the second phase of their home completed within the next three years.

Duncan has been devoting time to a project in which he has designed four affordable, rented homes on Lindisfarne.

The timber-frame homes, for the Holy Island of Lindisfarne Community Development Trust, should be ready by the New Year.

They are intended as lifetime homes in which walls and space can be easily adapted to meet the changing needs of the occupants.

He also runs an annual course on self-build timber frame homes and Mary works part time for the Scottish Ecological Design Association.

Duncan is also working on a project in Norfolk where a family are self-building.

He says that one of the advantages of the system is that outlay is minimised and controlled in the early stages and homes can be added to as families grow. "For our own home we are not borrowing any money. We are building for cash and everything depends on income and the time devoted to the building work.

" It takes as long as it takes. "But you can create a place to your own requirements, in your own time, and you can make it as environmentally-friendly as you want."

The open days, from noon to 4pm today and tomorrow, will help raise the profile of eco self-build.

Duncan estimates that only around 8% of new homes in Britain are self-build.

"Elsewhere it is a lot higher and in Belgium, for example, it makes up a third of homes," he says.

STRATEGY Architects Duncan Roberts and Mary Kelly who are self-building their eco