Up on the Roof
Along with the complete renovation of the existing buildings, the new apartments at 1247 Wisconsin Avenue are part of a small mixed-use development in the historic Georgetown neighborhood of Washington by McInturff Architects of Bethesda, Maryland.
In many ways the model is not unique; housing over commercial spaces is certainly not a new idea. Developing an existing roofscape to extend that model for housing, however, is a new approach.
The existing buildings consisted of two 19th-century townhouses facing Wisconsin Avenue with a footprint 45 feet (14 meters) wide and 180 feet (55 meters) deep between the avenue on the front and a usable alley at the rear.
The buildings were originally only 60 feet (18 meters) deep, but over time, the additional 120-foot- (36.6-meter-) deep space running to the alley behind had become a warren of small spaces with little or no architectural merit.
With approvals from the local historical commission, McInturff was able to preserve and upgrade the two existing townhouses, which consisted of a first-floor commercial space and four upper units.
This work also included completely renovating the remaining 20-foot-high-by-120-foot-deep (six-meter-high-by-37-meter-deep) portion off the alley side, creating, in effect, a new platform or elevated garden on which three additional side-by-side units and a smaller stand-alone house were built.
More space — a new site really — was thus created in this dense neighborhood for two of the existing apartments and four new units without increasing the built footprint. Many rooftops in cities and towns across the country could be transformed like this project, which is an example of real sustainability.
The new rooftop site was conceived as an urban oasis for all of the units. Placement on the roof high above the street level provided both good light and good cross ventilation for the hot, muggy summer days that the Washington, D.C., area is known for. All six roof units now have their own private terrace with individual bamboo gardens that provide shaded areas to sit.
Mark McInturff probably could have packed the roof with more units; instead, he placed three new units a few feet back from the edge of the alley parapet. This provided a small deck area and more privacy for two of those apartments, lessened the apparent height of the new construction, and also made a clear distinction between what is old and what is new.
At the same time, concentrating the newer apartments at the far end of the roof also increased the usable recreational area of the new roofscape.
One of the more interesting design decisions he made was to divide the mechanical equipment for the entire building into three parts and place them over the three new apartments.
This breaks their scale down into more manageable visual divisions and prevented what would have been one much larger chiller from occupying the rooftop area shared by all the units.
The new, two-story, 960-square-foot (89-square-meter) stand-alone house divides that roofscape in half. The developer thought a unit in the middle of the roof might clog up the new garden space, but McInturff argued that besides the attraction of another unit to sell, inserting it in the middle of the roofscape would have a number of distinct benefits for this unique site.
Most importantly, its side walls defined boundaries for all the other units and their outside spaces, separating all the individual gardens in ways that wouldn't have been possible if it had been left as one large space.
This small house is also an upside-down house with a piano nobile, meaning that the main living space occupies the second floor. Elevating the open-plan kitchen, dining, and sitting area to the second floor allowed for better cross-ventilation, light, and views looking out over the city. It also gave the lower-level bedroom the privacy of a south-facing terrace.
This small house, along with the other apartments in the development, clearly shows the potential of existing rooftops as new building sites in dense urban locations.
From a sustainable point of view, the units created for these spaces can also help discourage automobile use in favor of walking or mass transit, and reusing the existing building fabric can create new sites and communities without actually increasing the built footprint. This alternative may foretell the future for our cities and towns.
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Jeremiah Eck, FAIA, is the senior partner of Eck MacNeely Architects of Boston, Massachusetts, which specializes in residential and private school work. He is a former lecturer in architecture at the Harvard Graduate School of Design, a landscape painter, and the author of two previous books, The Distinctive Home: A Vision of Timeless Design and The Face of Home: A New Way to Look at the Outside of Your Home. Eck has built or renovated every home he has ever lived in.
This article is excerpted from House in the Landscape: Siting Your Home Naturally by Jeremiah Eck, copyright © 2011, with permission of the publisher, Princeton Architectural Press.