Property: Architect's brownfield of dreams

The house that John built is a shining example of how derelict land can be exploited.

IMAGINE A rectangular hunk of Cheddar with one corner pared off. That's the best way to describe the awkward end-of-garden plot that John Hart discovered tucked behind the university boathouses on the River Cam.

In this narrow space, measuring a mere 150 square metres, this imaginative Cambridge architect has designed and built for his own use a spacious two-bedroom house with garden and garage.

With its low hanging eaves, courtyard garden and fulsome use of warm materials, such as honey-coloured brick and European redwood, the Hart house combines a Japanese feel with that of an English medieval building. By taking advantage of every available inch in a highly imaginative way, it inspires new standards in urban housing. And all for around pounds 90,000, excluding the cost of land.

For Mr Hart, the culmination of years of ingenuity and hard slog came in September 1998 when the Royal Institute of British Architects (Riba) gave the house one of its prestigious Architects Awards - a well deserved pat on the back, not only for its space-defying design but also for the quality of craftsmanship.

The wood finish throughout is so good that you can't help stroking it. Mr Hart's previous home was a 14th-century timbered house in Suffolk, and he acknowledges vernacular influences like exposed roof beams. None the less, his creation by the Cam is resolutely modern in its approach to layout - to quote the Riba prize jury: "For such a small building, the house has an interior of surprising generosity." If anything, this is an understatement. Modest in scale it may appear from the outside, but inside the effect produces a gasp of amazement.

The house itself occupies just 80 square metres, and to avoid dead corridor space Mr Hart has all but banished interior walls. Yet open plan turns out to be as open as you want it to be. Despite being open to the rafters, the house feels cosy throughout. By clever use of Japanese-style screens and room dividers doubling as storage systems, he has created spacious yet intimate living areas that flow into one another.

The sleek, practical kitchen cleverly colonises the thin end of the wedge- shaped frontage, and the bedrooms occupy the back of the house, which is at a higher level than the living spaces to give a greater sense of privacy and calm. The house is exceptionally light and airy, itself a triumph in the face of adversity.

To squeeze every inch out of the site, Mr Hart needed to build right up to the boundary walls. Neighbours did not want their gardens overlooked, so getting daylight to the interior became his greatest challenge.

While free to put in sliding glass doors linking the interior to the terrace and garden, his solution elsewhere was to install narrow bands of glazing running along between the eaves and the tops of the outside walls. Known as clerestory glazing, this throws light up into the roof void and on a sunny day allows shafts of light to move steadily through the interior turning it into an impromptu sundial.

Mr Hart was equally determined that the house should remain private. To make the most of the river view without being overlooked by passers- by, he raised the floor level by half a metre so that you gaze over the heads of even the loftiest rowing Blues.

All the more remarkable is the fact that Mr Hart constructed the house virtually single-handed. He has built traditional wooden boats, but when it came to house-building he admits to having been a novice.

It was not supposed to happen like this. The search for a house in central Cambridge produced nothing but despair and Mr Hart found himself looking for that rarity, a well-situated brownfield site on which to have a house constructed to his own design.

He planned to carry on working while project managing his own site. However, some builders that he had hired failed to live up to his exacting standards. They were firmly shown the door, and Mr Hart picked up where they left off.

But a diplomatic mission had to precede the elbow grease. Aware that two planning applications for the site had already failed, he went knocking on neighbours' doors. He presented them with two scale models, one of the dilapidated corrugated-iron repair shop that presently filled the site and the other of the proposed new house. Which would they rather have?

The neighbours were speedily won over, and what looked like the final hurdle - permission to run drains over adjoining private land - was overcome. However, at the 13th hour, neighbours (who have since moved) raised further objections.

For the whole year it took to conclude negotiations, Mr Hart worked on excavating a cellar Wooden Horse style, inside the existing structure. Once the derelict shed had been demolished, the project finally had lift- off. At first it was weekend working only but John eventually took the plunge and forsook architectural practice to labour day-in day-out on the house for 18 months. Five years slipped by from the time the site was bought to when the project was completed.

The marathon has paid off. The Hart house in Cambridge stands as a shining example of ingenious, accessible design. The current crusade is to make use of every scrap of urban brownfield land to build more homes. If only Mr Hart's contemporary haven could be cloned throughout our inner cities, people would be deserting the suburbs in droves.

John Hart, chartered architect, can be contacted on 01223 364000