Just inside the Design Museum's current 'Bauhaus Dessau' exhibition are three pristine architectural models. Surrounded by archive photographs and drawings, they represent the Bauhaus' first buildings in Dessau, then quite a small industrial town, where it had moved to from Weimar in 1925.
One, naturally, is of the pinwheel-plan Bauhaus complex itself, whose architect and director was Walter Gropius. A second is of the detached house which Gropius designed and occupied on nearby Burgkuhnauer Allee (now Ebertallee), while the third shows one of the three Masters' Houses, which formed a row on that same street (1925-26). These were flat-roofed semi-detached dwellings for Bauhaus teaching staff - not quite what 'semis' conjure up in the uk. They were occupied initially by Laszlo Moholy-Nagy and Lyonel Feininger; Georg Muche and Oskar Schlemmer;Wassily Kandinsky and Paul Klee.
The subsequent history of these buildings has certainly been chequered. Appropriated by the National Socialists in 1932, bomb-damaged at the end of the Second World War, and first restored in 1976, the Bauhaus complex is now the home of the Bauhaus Dessau Foundation - 'more than a museum ... a place for research, teaching and design', says one of its brochures. Gropius' house was largely destroyed in the war, and on its foundations there sits an incongruous pitched-roof 1950s replacement.
Of Moholy-Nagy's semi, also a casualty of the war, no trace remains, but Feininger's survived; restored in 1994 and open to the public, it is now a centre devoted to Dessau composer Kurt Weill. Muche and Schlemmer's house is currently empty, sealed and scarred. But at the end of the row, No 69-71 - Kandinsky and Klee's house - looks as pristine as that Design Museum model. Under the aegis of the city of Dessau, its owner since 1932, it has just been restored by Berlin architect Ralf Pfeiffer (with Dessau engineer Codema International) to serve as a museum to those two celebrated artists.
Ebertallee is still a residential street on which stolid hipped-roof houses predominate. In these conservative surroundings, it is hard to believe that No 69-71 is now 75 years old. From the roadside, seen through pine trees, it presents blank white walls but for two substantial areas of glazing. One, reinforcing the horizontal emphasis of the house, belongs to the two adjacent, north-lit, first-floor studios projecting over the storey below; the other, the only real counterpoint to the horizontality, is the broad strip window running up the height of the building in Kandinsky's stairwell. Even at a distance the colours of the staircase - red, yellow and white - are conspicuous. It is apparent already that this is no ordinary interior.
Despite their prestigious first inhabitants, and their prominent studios, these three semi-detached houses shouldn't just be treated as well-appointed rarities for a small minority. To Gropius, they were bound up with a continuing pursuit of industrialised building methods, of forms of standardisation in design and construction that would not discount individual choice.
As early as 1910, while he was still employed in Peter Behrens' Berlin office, Gropius sent a memorandum to the president of the aeg electricity company - belatedly translated in The Architectural Review (July 1961) as a 'Programme for the Establishment of a Company for the Provision of Housing on Aesthetically Consistent Principles'. In this he extolled the multiple ways in which standard, mass-produced elements could be combined: 'Each house is in the end its own self by means of form, material and colour.'
A more direct precursor of the Masters' Houses was the 'Giant Building Blocks' proposal which Gropius made in 1923. A related drawing shows six separate spatial units in combinations of increasing complexity. These cubic components have a stark, introspective, rather Loosian look. At the Masters' Houses the fenestration is more generous, and connections between inside and out more integral to the design, but the 'building blocks' principle of interlocking standard volumes still applies.
The two L-shaped halves of these dwellings are, in plan, essentially a mirror-image of each other, rotated by 90degrees; so the staircase window in Kandinsky's part faces north and, in Klee's, west. Each has a ground floor terrace and first floor balcony (also L-shaped), whose long side in Kandinsky's case faces east and, in Klee's, south.
Structurally, the Kandinsky-Klee house is something of a hybrid, incorporating a reinforced concrete frame with (sometimes loadbearing) walls of Jurkosteine - a block formed of cement, sand and slag. Inspection of Klee's cellar shows that brick was also used in places. Built at a time of experimental methods and materials, the house was roofed with a peat-based product, Torfoleum - unsuccessfully, for the roof began leaking soon after completion. (In an exhibition in the basement of the Bauhaus workshop wing, there is a sample of Torfoleum on display; it looks like a chunk of cracked earth after a disastrous drought.)
The restoration, however, has had to address later alterations to the house as much as faults in its construction. From 1932 it was used by the local Junkers factory for middle-management accommodation. By the close of that decade the continuous steel-framed studio and staircase windows had all been replaced by wood-framed substitutes in traditional format, while brick chimneystacks were added to the house. As a newspaper cutting from 1939 proclaims, it was now fit again for decent German citizens. During the post-war period of the German Democratic Republic (GDR) it continued in rental use, without further major changes.
Gerhard Lambrecht, head of Dessau's department of culture, oversaw the restoration. 'We wanted to return the building as far as possible to its original appearance. This meant removing the chimneystacks andtaking out later subdivisions which had altered the interior spaces. Above all it meant reinstating the staircase and studio windows which were so integral to the house.'
As all the original elements of those windows were lost, this required a search of documents in the Busch-Reisinger Museum at Harvard University, where Gropius' archive is now held. The windows were reconstructed from drawings located there and, on the insistence of the monuments conservation authority of Sachsen-Anhalt (the province in which Dessau is situated), they were not adapted to accommodate double glazing.
'Otherwise the philosophy was to retain the original work wherever we could,' adds Lambrecht. 'We didn't take off all the rendering, for instance, but just repaired it in places.' Less than 40 per cent was renewed, and though the older work is not so even, the overall consistency is hardly impaired.
Structurally, there was localised corrosion of the concrete reinforcement, and about 10 per cent of it was cut out and replaced. In just one area - the cantilevered balcony of Kandinsky's house - this corrosion demanded an additional response. The balcony, unstable and sagging, is now supported by three slender steel columns (see front cover); a better option, it was felt, than to damage the original fabric by total renewal of the concrete slab.
On the whole, says Lambrecht, the shell was in good condition: 'The people who lived here may not have been great fans of the house, but they looked after it.'