CHALLENGE Typically, renovating an urban parking structure allows limited opportunity for a strong architectural statement, never mind an innovative lighting solution. So when asked to expand a parking garage for the Minneapolis Community and Technical College (MCTC), the architect and lighting consultant recognized an opportunity to overcome this long-standing dilemma.

ARCHITECTURAL and LIGHTING SOLUTION The team of Bentz/Thompson/Rietow Architects of Min-neapolis, with lighting design firm Schuler Shook, also of Minneapolis, created user-friendly drama via a lighting effect that camouflages the existing parking ramp and emphasizes the site as a gateway to the area. (The campus is located in downtown Minneapolis on Hennepin Avenue, a major access thoroughfare for the city's theater district.)

To accommodate a growing student body, MCTC built a fourth level atop the parking structure, originally constructed in the 1970s, to provide 220 additional parking spaces. The school's administration also saw the expansion as an opportunity to link the facility visually with the adjacent campus. 'First, the exposed concrete spandrel panels, which had turned a mottled gray over the years, were stained to match the light yellow brick accent bands of the classroom and administrative building across the street,' says design principal R. Bruce Cornwall of Bentz/Thompson/Rietow. Painted steel, anodized aluminum, brick, and glass materials also recall details from other campus buildings.

Most parking garages are wrapped in solid opaque materials that give them a foreboding fortress-like appearance. 'Our solution was to use light in combination with building materials that would emphasize luminance and make the structure seem less bulky,' says Cornwall.

To achieve this, anodized-aluminum industrial grating was turned on its end to create the skin and row of 'light columns' that march down the front façade of the facility. The panels are fastened to painted steel brackets, and the light columns topped with frosted acrylic discs. Placed at the columns and gratings are 400W metal halide floodlights. Their glow reflects off the metal skin, giving it a silvery patina that spills onto the sidewalk.

Schuler Shook partner Michael DiBlasi says that the lighting plan was based on an overall design program to make the building look attractive both day and evening. The bar grating and the glass caps atop the columns are relatively common building materials that the designers used creatively. 'The bar grating acts like scrim on a theater stage,' DiBlasi points out. 'Depending on the angle of the source, its surface reflects the light in different ways.'

All former high-pressure sodium lamps were removed and the structure uniformly illuminated with metal halide lamps from Philips, housed in fixtures from BD Lighting and Kim. 'This transformed the structure in the evening to blend with two adjacent buildings that we had previously lit with metal halide-the Basilica of St. Mary and the library, creating a ribbon of pleasing white light along the streetscape,' DiBlasi notes. To accommodate changes in the building's elevations, four different wattage lamps are in use: 70, 175, 275, and 400, the latter as a tight spot for the columns.

'The discs capture the projected light from the base of the columns to create a halo,' explains Cornwall. He notes that the 'halo' reference works well with the nearby basilica, which the architect complemented in aspects of the structure's design: The curved form of the grillwork references the dome and stone detailing of the historic landmark, while its transparency both enables a view of the church and hides the mundane parking structure.

Anchoring the façade are stair towers topped with green channel glass. Inside, 175W metal halide uplight/downlight wall sconces are perceived as softly diffused beacons that establish the building's new contemporary presence in the surrounding cityscape. Pole lights, 25 feet tall and fitted with 400W metal halide, provide illumination for the open top level. At the entrance are coordinating 12-foot-high pole lights with 250W metal halide. Existing interior pendant-mount luminaires were refitted with 175W metal halide and feature a vandal-resistant acrylic lens. Decorative wall sconces provide accent illumination. To address the safety concerns associated with parking facilities, the design actually exceeded code requirements.

MCTC president Phil Davis praises the finished product. 'The project complements our new library and creates a striking gateway to the campus and downtown Minneapolis.' vilma barr