Keeping a good house.

Architects' houses have traditionally been a vehicle for critical self-development - in South Africa, even more so, given the scarcity of acceptable commissions. Here we present three houses that respond in very different ways to context and their architect owners' concerns.

Gabriel Fagan is the polymath architects aspire to be. After studying civil engineering prior to taking up architecture, he has an instinctual feeling for and knowledge of all things technical. Added to his skills as a designer are those of a craftsman who builds his own boats, plane and house. A legend as a sailor (in the oldest craft he won the Cape to Uruguay race outright) and pilot, he is a remarkable photographer, and a musician too. This house which Fagan, his wife and children built for themselves is one of an impressive series which would have brought him to wider attention if South African architects had not been banished from international publication during the apartheid years. Designed some 30 years ago, it reflects a concern then shared by a number of other architects: to create a regional vernacular rooted in historic Cape Dutch architecture, yet thoroughly modern. To this Fagan brought his own craft skills, which has allowed detailing no builder could execute, and a further concern with what is now called passive environmental controls.

High up in Camps Bay, a suburb close to central Cape Town, the site slopes down from the road to the main double-storied volume of the house. This looks out in the opposite direction across a nature reserve to where the fierce westerly sun reflects up from the Atlantic. Looming steeply behind the house is a corner of Table Mountain, down a cleft in which the wind buffets at speeds of up to 100mph. Coping with this challenging microclimate while opening up to the Cape's balmy Mediterranean-type climate are concerns that shaped the house, including the decision to build in heavyweight, high thermal inertia materials. Walls are thick brick, plastered and painted white. Ground and first floors are thick concrete slabs paved with quarry tiles and linoleum respectively. If shutters are left open, these absorb heat from the afternoon sun and radiate it during cool winter nights, minimising use of the underfloor heating. Where the first floor slab extends as a roof towards the street, it is grassed over to provide an increased level of insulation.

The house is subdued towards the street. The main block is set back across a sunken court where only two things catch the eye: the roof's wavy profile conjuring vague echoes of Cape Dutch gables, and the plastic forms of the projecting fireplace and chimney which recall those of farmhouse ovens: The entrance carries you forward, as if in a torrent. From the bottom of the narrowing cascade of stone steps, a floor paved in round river stones carries you past the copper-sheathed front door to ramp down to a widening eddy below a Skylight before emerging on a raised timber landing that projects into the living room. Here you are stopped short, by the hollow sound underfoot and the need to change direction of movement, but most especially by the immensity of the sun-basked space which extends to either side and the magnificent view across it and down to the Atlantic Ocean.

The landing Commands a pivotal position in a single, 60 ft long space. Level with it is the dining area which opens through sliding doors into a walled patio that is part of this space. Down a few steps is the living room. Inside the piers that form one long side of this (and between which is seen the sea) are four sliding screens, each a 11[feet] 6[inches] x 11[feet] 6[inches] glass sheet held in a U-shaped wooden frame. Each sheet is held at the top by only a diminutive aluminium channel, and the frame's bottom member is hidden in the larger channel in the floor that it slides in. So even when the screens are closed, the virtually uninterrupted continuity outwards of ceiling and floor gives the impression of the room being an open gallery perched above the sea. As an utter contrast to this expansive openness, the opposite side is dominated by the introverted enclosure of a huge fireplace that you can step down into sit on a ledge that folds around it as an extension of the hearth. A longer flight of suspended treads rises from the landing to the first floor. Here the four bedrooms are organised symmetrically so that a pair shares each of the two bathrooms, an arrangement exactly complemented by an ingenious vaulted roof. Partly inspired by Gaudi's workshop roof at Sagrada Familia this covers bedrooms with extroverted vaults and bathrooms with sagging valleys. Like the living room below, each bedroom can become a balcony open to sea and mountainside. Bathrooms enjoy the counter-view of the mountain top where cut-outs in the roof are covered by perspex hatch-covers. These slide open so that ablutions too can be enjoyed semi-outdoors.

Pared detail and harmonious proportions (many of them from Le Corbusier's Modulor), in conjunction with the sliding layers of the sea front, contribute to what is probably the most remarkable aspect of the house: the ever-changing moods which play across its serene repose. Shifts of sun and weather register intensely in these stark yet richly convivial rooms, where use can alter moment to moment with seemingly reciprocal changes in their character. Hence the living room combines built-in and lightweight movable furniture that is nomadic, always migrating as required. In a single evening the room might change from being the sunny balcony of a solitary reader, and then that of a chatty gathering, later to become the auditorium for a performance on the stage-like dining area, and lastly a soft-lit backdrop to the family tightly gathered around the fire. Here is a house of strong personal character and local resonance that is utterly responsive to climate and all those who built it and live there.