20 January 2010
Deffaa Residence -- stair
The consequences of creating this almost arbitrary cut into the brick masonry shell could hardly be more surprising. From the outside, the uninterrupted column of glass blocks spanning the first and second floors suggests the presence of a relatively large space with a high ceiling.
In truth, the house contains no such high, open airy space. Rather the slot admits light to the narrow stair beginning at the far side of the living room and climbing steeply toward the center of the house where it is surrounded by sleeping quarters, bathroom and an outdoor terrace.
The house's interior isn't particularly flooded with natural light although a grouping of windows at the southwest corner of the living room does admit a healthy dose of light.
Nevertheless, the visceral shock of the vertical slash at the stairs is all the more gratifying for being unexpected. The light admitted in this corner penetrates to the core of the house, lighting and orienting the staircase as a primary organizational feature within the home.
Armstrong's desire to keep the glass blocks clear of any structural or visual interruption from the interior results in some unusual cantilevering of a second floor bedrooom, held up over the point of maximum tension where the stair turns ninety degrees and a support post would normally be encountered.
In fact, the original construction drawings for the house (in plan, interior elevations and stair details) Armstrong indicates the use of a round wood post at this location. Perhaps he realized once the framing was underway that the post was not structurally necessary given the rigid framing of the floor diaphram (including 14" and 7" high steel 'I' beams to maintain the open column free areas of the living and dining rooms.
Instead, a curious sense of open lightness appears where it would be least expected. Far from being a generic white International Style cube, the house creates a spatial and structural puzzle of interlocking rooms and elements.
The use of a simple bent bar of solid aluminum provides just the right contrast, complementing the unusual cut out of the wall and overhanging unsupported ceiling.
Photographs by Andrew Raimist. Architectural drawings courtesy of the Harris Armstrong Archives, Special Collections, Washington University in Saint Louis.