Distanced in time and space by a little over one hundred years and the width of a street, the creative architectural practices of Steven Holl Architects and Charles Rennie Mackintosh engage on the slope of Garnethill. The original Glasgow School of Art building evidently has a new neighbour, the Reid Building.

Designed and won in competition by Steven Holl and his partner, Chris McVoy, of Steven Holl Architects (New York) in association with JM Architects (Glasgow) the new building accommodates a relocated Directorate, Design School studios, specialist workshops, auditorium, refectory, exhibition spaces, a new visitor centre and the Student Union.

The parallels and inverted contrasts between the two buildings are perhaps obvious and intriguing, not only in their respective programmes and geographically mirrored situations but also in their architects' ceaseless preoccupations with light, construction technique and spatial disposition which so emphatically inform the day to day experience of both buildings.

The exhibition chronologically charts the design development of the Reid Building and depicts the driven voids of light, the circuit of connection, the circulation which encourages the notion of creative abrasion and the reversed construction method of thick skin/thin bones as in Mackintosh against thin skin/thick bone of the Reid Building.

Steven Holl's use of watercolour sketches, or in his words 'drawings with a wet brush and charcoal', investigate and visualise the compositional form, appearance and spatial qualities of the interiors and the facades, in particular the sourcing and the controlled interplay of natural light. These concept sketches initiate model studies, which then inform new sketches, in an iterative cycle of critiques and discoveries within the studio.

Like Mackintosh before him, Holl exploits the expressive luminosity of this medium in small sketchbooks but unlike Mackintosh's gentle, geometric precision in his recording of flowers, interiors and landscapes, Holl's is a more vigorous, though highly considered, use of watercolour which is freer and obviously quick in evocatively capturing the intended coalescence of space, form and light.