While Louis Kahn's wing of Yale University Art Gallery in Connecticut has been closed for restoration, a large banner has hung on the entrance facade with a quote from him: 'Every time a student walks past a really urgent, expressive piece of architecture that belongs to his college, it can help reassure him that he does have that mind, does have that soul.' Kahn was, of course, one of the great architectural educators - he taught primarily at Yale and Philadelphia - but the greatest lessons come from his buildings.
The Kahn addition, built in 1953, has been restored as part of the first phase of the masterplan for the Yale Arts Area.
Further phases include restoration of the infamous Art and Architecture building (Paul Rudolph, 1963); constructing a new History of Art department (Charles Gwathmey, now on site); remodelling the other existing gallery buildings (the Street Hall building, 1867, and the Swartwout building, 1926); decanting and reorganising the arts, architecture and history of art departments, and a complete overhaul of the library and arts storagemanagement systems.
The restored Kahn building opens this December, and all the masterplan works should be complete by late 2010.
The architect for both the masterplan and the Kahn restoration is the New York practice Polshek Partnership Architects.
The gallery was the first major project that Kahn completed. And while it reveals much about his work, and how he tested the prevailing Modernist thinking of the time, it is foremost an intelligent, humanly imperfect and extremely fine building.
It offers a simple yet strong face to the street - a solid brick facade with no openings, enlivened by stone string courses, that mark the locations of the floor slabs and give order to the plane of brick. It sits tight to the pavement line, so you do not get a flat-on elevational view, but you are aware that the height and proportions equate to its neighbours; although stylistically in contrast, it is extremely well mannered.
The connecting element to the Swartwout building, also elevated by a solid brick plane, is set back to allow for a small entrance area where there are wide steps at 90° to the facade, leading up to the main entrance. The entry sequence is modest, non axial and unassuming.
The plan, which is revealed in full when you enter, is rigorously proportioned and fully resolved, a feat made more impressive when you realise that this is not an object building on a greenfield site, but an extension which has to deal with the constraints of an existing building and a restricted, complex, urban site. The main body of the building is made up of two doublesquare spaces (40 x 80ft) separated by a smaller rectangular 'servant' space that contains a circular stair-tower and rectangular core areas (lift, stair and WCs). A smaller area (40ft square), behind the entry court, connects the main body to the Swartwout building.
The north and west walls, in contrast to the solid south and party wall to the east, are fully glazed.
The most dominant element is the ceiling, a concrete tetrahedral grid - a sort of solid space frame - which sets a triangular grid across the space; it is not surprising that Kahn used the reflected ceiling plan as the defining drawing of the building.
The gallery is humane in scale, with none of the monumentality that you get in later (admittedly larger) Kahn buildings. The floor-to-ceiling height of 10 feet 6 inches is low, and the pyramidal concrete voids are more in shadow than in light.
Fortunately, there is so much horizontal expansion, with the flow of space lit by the continuous expanse of glazing to the north and west, that there is no sense of oppression.
There is an intense visceral quality to the building, due to its concrete ceiling; the concrete columns with rough, timberplank shuttering marks; the cast drum of the stair; the pinkishbrown blockwork walls to the north and on the lift core (the blocks are small, hand-sized); the end-grain oak floor and the polished terrazzo strips marking the structural zone - a glut of materials with contrasting textures but unified by an earth-colour palette.
Your eye is drawn to the circular drum - it has a great presence in the space - but it is only when you are within it that you appreciate its beauty. The stair inside the drum is triangular and lit by clerestory windows, but the bright circular roof is disrupted by a triangular concrete slab, mirroring the plan of the stair, which both floats and looms down in the drum. The play of geometry, mass and light has a profound effect; it's a place of calm, where you feel far removed from the intensity of the gallery floors.
The building is gutsy, raw - yet incredibly controlled. You can clearly see the emergence of what we now think of as classic Kahnian ideas - the treatment of proportion and mass, the concept of served and servant spaces, and the expression of the making process, where the construction is the detail - which, although they were refined in later schemes, possibly have more impact here. You get the sense that Kahn was working things out; you can feel the intensity of the struggle. It is interesting to compare the gallery with his later building opposite - the Yale Center for British Art (1969-77) - which is less urgent but has more finesse.
Kahn's building was designed to be flexible, for gallery, studio and office use. The top floor was the architecture studio, before the architecture school moved to the purpose-built Art and Architecture building next door. For the gallery floors, Kahn developed a series of 'pogo' screens, which spring-fit between the ceiling and floor, with a 6-inch gap at top and bottom, to hang the pictures. These could be moved anywhere on the lines of the ceiling grid to suit the specifics of the exhibition hang.
However flexible in principle, the gallery had no tolerance, and after 50 years of heavy use, it needed a major overhaul. The conservation project has had three main objectives: to remove all the misplaced accretions (screens, partitions, covered-over external spaces) that had grown up over time; to upgrade services so that environmental conditions meet contemporary museum standards; and to replace the curtain wall, which had failed catastrophically.
Fortunately, the strip-out revealed that the accretions had not caused any major permanent damage and, after removal, the original finishes could be simply repaired, patched and cleaned.
Sounds simple, but, of course, difficult to achieve: for example, sourcing matching blocks was problematic (they were not a standard product), and it took time for the contractors, who were not experienced in 20th-century conservation techniques, to understand the philosophy behind the construction.
More complex was the overhaul of the services. A constant humidity/temperature of 50 per cent/68infinity fahrenheit has been achieved by replacing all the plant and doubling up the perimeter radiators. Extra lighting tracks, alarms, and a VESDA (very early smoke detection) system were installed. Most of the new plant is located in the servant area, where there is no tetrahedral grid, so it could be fixed in the ceiling behind the existing removable stainless-steel-mesh ceiling panels. Vertical risers were placed in the reorganised central core.
Threading new services through the tetrahedral grid was not straightforward. The air ducts did not have to be replaced (which was fortunate, seeing they were cast in situ), and the new lighting tracks and other wiring could be threaded through the open part of the diagonal ceiling structure with minimal drilling.
However, the lighting tracks had to be put together in 18-inch sections because of the geometry and lack of flex. This was slow, obsessive work.
In conservation terms, the most controversial part of the project was the replacement of the curtain wall. The original was a double-glazed steel section, welded on site, with no thermal break. Condensation streamed down the inner face, producing conditions wholly unsuitable for displaying art. The system had horizontal, but no vertical tolerance, and the expansion was putting pressure on the concrete floor slab. Repair or upgrading wasn't a realistic option, and the decision was made to replace the curtain wall.
The new system, which was tested with a full-scale mock-up and constructed off site, is a double-glazed, thermally broken aluminium section, with a baked, painted finish. The profile, colour and reflectance of the system match the original.
Replacement rather than repair is a pragmatic response essential in 20th-century conservation, where primacy is given to the idea over the actual fabric.
Strong side-light, even if predominantly north light, is not ideal for picture display. The light levels are controlled by scrims (sliding screens) and blinds, an upgraded version of the original blind system. Similarly, the pogo screens for picture display have been remade to match the original proportions. Light levels will be carefully monitored and modified to suit individual works.
Although Kahn's building is not landmarked (listed), so had no statutory conservation guidelines to follow, both client and architect were painfully aware of the intense scrutiny the works would receive. Overall, the quality is extremely high, the result of a successful relationship between a committed client and an experienced, intelligent architect, and high-quality workmanship.
But the project was a steep learning curve for the team; Steven Peppas, the project manager from Polshek, admits that the process was 'challenging and all consuming'. But none of the angst and compromise inevitable in a project of this type is visible in the finished building; everyone appears to have done an excellent job.
The building has a very strong character and is about as far from the concept of 'white cube' as you could get. It remains a challenge to inhabit; however, not only does Yale have a range of other exhibition spaces to complement it, but Jock Reynolds, the gallery's director, and his team of committed staff, clearly love the building and see it as a major exhibit in its own right.
The gallery reopens next month with a show entitled 'Responding to Kahn: A Sculptural Conversation', curated by the history of art, fine art and architecture students. Artworks from the extensive Yale collection have been chosen to form a dialogue with the building. The challenge for the students is to prove, through the curatorial decisions they make, that they have the mind and soul to match up to this urgent, expressive piece of architecture.
Yale University Art Gallery has its grand reopening on 10 December ( www. artgallery. yale. edu) Credits Client The Yale Corporation Architect Louis Kahn Renovation architect Polshek Partnership: Duncan Hazard, James Polshek, Richard Olcott, Steven Peppas, Lloyd DesBrisay, Robert Condon, Gary Anderson Construction manager Barr & Barr Builders Gallery and Yale University consultants Exhibition design Staples & Charles; wayfinding design Open; gallery & lobby lighting Hefferan Partnership; art storage Biblio Design; media lounge design Joel Sanders Architects; conservation/ environmental consulting Garrison/Lull Polshek Partnership consultants Structural engineer Robert Silman Associates; mechanical engineer Altieri Sebor Wieber; cost estimating Wolf & Co specifications Robert Schwartz & Associates; acoustics/AV/telecommunications Shen Milsom & Wilke; building code Hughes Associates elevators Van Deusen & Associates food service Romano Gatland landscape Towers/Golde preservation David DeLong; lighting Fisher Marantz Stone; security Ducibella Venter & Santore; exterior diagnostics/design James Gainfort; exterior wall consultant Gordon Smith Corp Barr & Barr subcontractors HVAC and plumbing Enterprise Plumbing & Heating; glass window wall Curtainwall & Windows Inc; electrical Paul Dinto Electrical Contractors; fire protection M J Daly & Sons; elevator Hontz Elevator Co; sitework Joseph Kelly Co; millwork Legere Group; masonry NER Construction; drywall S G Milazzo Co