Light spirits.

A scheme for a lighting showroom and offices on an unremarkable site in provincial Germany extemporises on the theme of light and transforms a blank box into a lyrical and functional work space.

Generally speaking, lighting design in Germany is dominated by high-tech sophistication, found at its most elevated in the products of Erco Lighting. As part of an attempt to establish a separate, distinctive image for itself in the market, ZumtobelStaff commissioned Bolles Wilson & Partner to design new offices in Lemgo, south-west of Hanover.

Zumtobel is an Austrian firm with refined, somewhat offbeat architectural sensibilities, evinced in the past by its commissioning Hans Hollein to design a showroom in Vienna, and Ettore Sottsass to design lights. Zumtobel's acquisition of Staff, which is a German firm, has breathed new life into the latter. Staff was famous in the '50s for the futuristic exuberance of its lighting designs, and blown up images from '50s catalogues have been used by the architects to decorate the walls of the new offices.

Bolles-Wilson's skill at drawing a narrative out of unpromising material - expressed abstractly and with architectural rigour, but recognisably narrative - was remarkable in its ingenious design of the Suzuki House fitted onto a tiny site in Tokyo (AR December 1995). The practice seems to revel in coping with awkward sites. In Lemgo, the problem was not so much awkwardness as blank anonymity. For the site was an amorphous black box, an industrial shed in undistinguished surroundings. It stirred, said Peter Wilson, a digitalised imagination in which islands of exoticism rise out of a bland computerised landscape.

Necessarily self-contained and divorced from a context of any significance, except the one of purpose, such essays can be distillations of an architectural approach; just as the design of an essential piece of furniture, a chair, a table, often is. This is so here. As in past schemes, like the Church House in Munster (AR October 1993) and again the Suzuki House, the practice has used boxes-within-boxes to establish islands of privacy and generate strange left-over bits of space. Such volumetric eccentricities have their own appeal, which the orthogonal cell - often the blight of conventional Modernist interiors - cannot.

Within its anonymous container, the scheme provides a large lighting gallery, conference room, offices and meeting rooms. The main space is the gallery marked out by free-standing walls for displaying lighting and enclosed by a white wall. This is an inner skin set away from the walls of the building to create the series of odd-shaped spaces used for the offices and meeting rooms.

With characteristic abstraction, Bolles-Wilson has extemporised on the theme of light, so that it is the lyricism of light rather than the technical performance of the objects that produced it that seduces you first. This is surely the right approach.

Metaphorical allusions are easily inferred in these circumstances. Overhead for instance, a constellation of geometric planes of light, called Technical Clouds by the architects, float underneath existing ceiling trusses, blacked out to simulate a dark void. As the name suggests, these planes are display panels for the firm's lighting, as are the free-standing walls. One wall cut by geometric pools of light stands opposite the reception desk and is an appropriately luminous introduction to the place.

A pattern of light curves, known to lighting engineers as the cd/klm distribution diagram, is traced out over the floor of the gallery. One curve projected vertically delineated the form of the substantial core of the scheme, the conference hall for 80 people at the centre of the diffuse light-filled space. The shell is clad inside and out with sheets of burnished cherrywood, the material and colour seeming all the more rich and sumptuous in the immaterial circumstances. Once inside the hall, you see these solid walls are floating, separated visually from floor and ceiling by continuous ribbons of light. Light installations, including eight computer-controlled light settings, are accommodated by recessed ceiling coffers.

The architects' pleasure in counterpoising materials, which they do most delicately, and in manipulating light, is encapsulated particularly well in this small scheme; and their habit of detailing inexpensive materials carefully is constantly pleasing.