ARCTIC ARTHOUSE.

Reusing buildings is a vital part of the green agenda and one that needs encouragement. Inventively inserted into an old harbourside warehouse, this new art museum creates an important cultural and social focus for Reykjavik.

Since the virtually unknown partnership of Studio Granda won an international competition for Reykjavik city hail in the late 1980s, their progress through a series of major Icelandic civic buildings has been quietly assured. Both the City Hall (AR October 1992) and the later Supreme Court (AR August 1998) are remarkably mature reflections of local concerns about civic identity and the imposition of law in a small community, combined with an incisive approach to materials and context. The result is a rigorous yet romantic Nordic Modernism, paradoxically grandiose in form and painstaking in detail. As Steve Christer, the English half of Studio Granda, observes 'there are only two scales in Iceland: the massive and the tiny'.

The practice's latest building, a new art museum in Reykjavik, differs in important respects from its predecessors, although the architectural outcome is equally intriguing. First, the programme is a cultural one, suggesting a freer rein compared with the proscriptions of lawyers and civil servants; and second, the building already exists, providing a framework for intervention and dialogue. It also advances, to some extent, an understated (but important) conception of ecological awareness, since reusing existing buildings is inherently less wasteful in terms of energy and resources than new construction.

Studio Granda's competition-winning proposal occupies two floors of the south wing and three floors of the north wing of a large harbourside warehouse, originally built between 1933 and 1939. Made of concrete with a distinctive mushroom headed column structure, the warehouse has a robust dignity and

solidity, typical of the best industrial functionalism. Icelanders were enthusiastic converts to concrete following its introduction in the early part of the twentieth century. It succeeded turf and indigenous basalt rock which is notoriously difficult to work. The harsh volcanic geology of the Island also lacks naturally occurring clay for making bricks and mortar.

The two wings of the warehouse are arranged around a long thin central courtyard. Studio Granda's main move bisects the two wings in plan with an angular spine that follows the line of the original pier for the port of Reykjavik. Discovered by the architects after studying historic maps of the harbour, the pier was the umbilical cord that linked Iceland with the outside world, channelling resources, culture, artefacts and supplies. Its archaeological imprint now underscores the physical and metaphorical evolution of the new museum. The spine/pier leads from the entrance hall in the south wing through the courtyard, terminating in a tall glazed opening overlooking the harbour. It also links two sets of staircases that lead to the upper floors in each wing. Along the length of the spine, a sumptuous black walnut floor and hot-rolled steel sheets tightly bolted to walls and columns (like a fetishistic metal corset) introduce an Intentional air of Stygian gloom into the predominantly white, luminous spaces.

Externally, the warehouse has been simply spruced up and painted in what the architects describe as 'Fishery Protection Vessel Grey', with the museum parts demarcated in white. An implausibly angular concrete canopy shafts in to the south flank to denote the main public entrance. Cunningly, the canopy also reflects light into the double-height entrance hall, illuminating its black floor and steel plate walls that mark the beginning of the spine/pier route.

The parti is both elegant and economical. Flanking the entrance hall are the museum shop made of raw concrete and cloakrooms enclosed in a delicately crystalline glass box. Galleries are distributed through both wings, with the museum cafe and library housed in the north wing at the end of the spine. Delivery, workshop and storage occupy the ground floor of the north wing, connected to a service entrance on the harbour side. Offices and the museum's architectural archive are located on the second floor of the north wing.

Cutting through the courtyard, the sping/pier defines a large external exhibition space on the east side and double-height white room on the west that can be adapted for various uses. Two hefty steel doors open up the spine to the court, and further sets of folding doors reveal the white room beyond. A skylit box illuminates the spine (in the manner of Herzog and de Meuron's light beam at Tate Modern, AR April 2000) and at night its softly palpitating glow washes through the court.

The sextet of galleries share an ascetic palette of concrete and white wall planes, but subtle variations in form, scale and the play of light gives each a particular character. Daylight is admitted indirectly to each gallery space and arrangements of sliding or folding screens can create totally artificially-lit conditions when required. The antiseptically white walls of the new galleries contrast with murkier spaces where the original concrete structure and chunky octagonal columns have been retained.

Studio Granda's meticulous use of materials and spare detailing has a clear kinship with Caruso St John's recent Walsall Art Gallery (AR May 2000); interestingly, Christer was a contemporary of Peter St John at the Architectural Association (where he met his Icelandic partner Margret Hardardottir.) The two buildings also have programmatic resonances, in trying to provide small, regional urban centres (despite being a European capital city, Reyknavik's population is only around 100 000) with a transcending sense of culture and identity. In a quiet yet determined way, both buildings succeed, enlivening the rational through sheer sensuality and an absolute delight in design.