Beyond the fringe: The design of a pool house built in the grounds of a historic house in a quintessential English setting challenges familiar perceptions. (ar house).

Dense and immaculately trimmed, the massive thatched roof of the pool house floats above sheer glass walls fringed by delicate grasses. Along the ridge, a feathery hedgerow grows against the glass of a long skylight. Set in an English garden against a sixteenth-century stone wall, the building gently subverts the familiar and introduces a surreal element into a quintessentially English setting.

This is familiar Ushida Findlay territory. All their structures -- Truss Wall, Soft and Hairy House, 1009 Footpath (an equally hairy, undulating sculpture in an Adelaide park), Kasahara Amenity Hall (AR March 2001) -- are products of a quicksilver originality. Drawing inspiration from place, as most architects do, this practice seems able to design by drawing on dream-like, poetic impulses to unsettle and delight without sacrificing efficiency.

The building is an addition to a listed country mansion in the south of England. Originally Tudor, with Queen Anne and Arts and Crafts accretions, the house has a Gertrude Jekyll garden, and land which, surrounded by a protected sixteenth-century wall, provided the site for the new swimming pool. Its sensitivity was plainly going to be a constraint on new building, but in approaching Ushida Findlay, whose work they had seen in Japan, the clients were seeking the unexpected.

This practice has a habit of borrowing familiar ordinary materials and using them in ways that challenge perception of them. In the heavily polluted tile-making town of Kasahara, the glimmering, curving mosaic-clad carapace that contains Ushida Findlay's new hall celebrates the industry and lends it a fleeting visionary glamour. Similarly in Adelaide, in the midst of quintessentially suburban Australia, their brushwood sculpture picks up on the familiar garden fences and turns the material into art.

Curiously, given the familiarity of thatch in the context, Kathryn Findlay's use of the material in this south of England garden was suggested by earlier research into the lost art of shibamune -- Japanese thatch (literally 'green ridge') -- when teaching at the University of Tokyo. Ando Kunihiro's Traditional Crafts for Houses depicts a vernacular reed-covered roof with flowers planted along the ridge. (The same practice is followed in Normandy where ridges are secured by being planted with irises.) Findlay's adaptation of and enlargement upon the idea splits the denseness of the thatch with light and at the same time eliminates possible waterlogging in a damp climate. Instead of ridge planting she has inserted the glazed top light and surrounded it with planters buried in the thatch. Bamboo rods, instead of traditional English hazel, hold down the neatly combed wheat reed of the ridge. More or less invisible to the casual eye, they nevertheless mark provenance of the roof's design.

Backed up against the old stone wall, the building adjoins the main house and faces south across a newly planted garden. Seen from the south, from behind beds of tall plants which obscure the glass walls, the roof is at first almost familiar making revelation of the whole building all the more surreal. But in spite of surreality, the gabled structure is straightforward. The roof rests on a glulam substructure supported on concrete posts with glass panels fixed to hollow steel sections.

A more ethereal, almost transient, experience is provided by the interior of the building. Light bounced down from the skylight, and transmitted by the transparent walls, reflects off the water and pale limestone paving, and off the curves of a tented ceiling made of Barisol - stretched rubber fabric from France and painted luminous white. On the south side, the curved rim of the thatched roof casts a dark shadow and forms a canopy over the stone walkway outside.