Conservation on the Kalahari
A racially diverse Building Team uses the aesthetic qualities of brick to lend a distinctive flair to a sustainable, mixed-income condominium project in Harlem.
August 11, 2010
|Geometric brick patterns on the street-facing façade of the Kalahari condominium tower in Harlem were inspired by traditional African motifs. PHOTOS: DEBORAH GEIGER|
While New York City's Harlem is home to many ethnic groups, its character is largely drawn from its African-American population. The Kalahari mixed-use condominium development draws on decorative traditions of its namesake African region, including distinctive colors and patterns on its brick exterior walls. “This building could only be in Harlem,” said designer Fred Schwartz, FAIA, principal of New York-based design architect Frederic Schwartz Architects.
The development's two 12-story towers face, respectively, 115th and 116th Streets and contain 249 residential units. Geometric patterns of the brick on the towers' street-facing exteriors make a striking reference to Africa. Three Adinkra symbols from West Africa appear on the pilasters of the ground-level exterior. The two-story lobby connecting the towers features a collection of art on African and Harlem subjects. Earth-toned pavers allude to the Kalahari plain, while the shapes and patterns of the lobby's furniture and furnishings suggest the plain's wildlife, according to Jack Travis, FAIA, of Jack Travis Architects, an African-American consultant on urban and environmental design. At street level, the development houses retail stores as well as the African-American Film Center.
The towers' geometric decoration has much the same function as such decoration on the mud huts of the Kalahari, said Carlton Brown, chief operating officer of Full Spectrum of New York, which developed the project with L&M Development Partners, a New York firm. In Africa, huts are painted by their owners with distinctive decorations that provide identity in the absence of street addresses. The Kalahari's facades provide a similarly prominent feature, so much so, said Brown, that the development is known among locals by its name rather than its street address.
Given the prevalence of brick buildings in Harlem, Schwartz said that it was decided early to create the design by means of four colors of off-the-shelf bricks. Initially the Building Team planned to use a panelized system, but concerns about the fabricator's ability to meet the schedule resulted in laying the load-bearing brick by hand. The general contractor, First Avenue Builders, based nearby on 116th Street, delivered the hand-laid brick for the same cost as a panelized system, according to Brown.
Large pictorial drawings were supplied to the bricklayers to guide them in creating the African motif, said David E. Gross, AIA, of local design firm GF55 Partners, the project's executive architect. “The bricklayers enjoyed the challenge of an unusual project and took a lot of pride in their work,” he said. Walls that do not face the street were clad in EIFS.
Cutting energy consumption
The developers set a goal of LEED Silver certification, and energy consumption was designed to be 31% less than that mandated by the New York State Energy Code. Among the measures taken to achieve that reduction was computer analysis of thermal bridging in the building envelope. Consultant Stephen Winter Associates used the Lawrence Berkeley National Laboratory's THERM program to predict heat flow rates through the envelope's materials. The results enabled the design team to detail walls that avoid cold spots and condensation.
Five rooftop heat exchangers temper the development's fresh air with energy recovered (at 62% efficiency) from its exhaust. Asthma from urban pollution is a common condition in Harlem, especially among children, and the developers set high standards for low-VOC materials and indoor air quality. The buildings are positive pressurized, with duct-supplied outside air that passes through filters with a MERV 13 rating, according to John Rice, a partner in the MEP consultant firm AKF Engineers, Stamford, Conn.
About one-fourth of the Kalahari's electrical needs are met with off-site wind generators. The $114-million development also has a photovoltaic system consisting of 190W multi-crystal-type silicon panels connected to the main switchgear assembly. The panels, which are designed to produce about 27,000 kWh per year, are located on the tilted incline roof of the five mechanical penthouses. Additional energy-saving measures include low-e glazing, self-condensing hot-water heaters, and Energy Star appliances.
To further reduce its environmental footprint, the Kalahari has 25,000 sf of vegetated roof, largely over the lobby connector, Brown said. While some of the green roof adjacent to residential units is private, most is common area with benches, plantings, a fountain, and a children's play area. Rapidly renewable bamboo was used for the flooring in the residences. Zipcar, the national car-sharing service, houses several cars in the garage.
The developers had hoped to install a geothermal system, which Full Spectrum's Brown says would have reduced energy consumption 55% below the state energy code. The Building Team determined, however, that it would not have been financially feasible to construct the necessary underground wells, given the configuration of the building's foundation and parking garage, so the idea was scrapped.
The developers were committed to an integrated, mixed-income residential community. The Kalahari has 120 units of affordable housing and 129 market-rate residences; every floor has both unit types. The members of the Building Team were similarly diverse in racial and ethnic background, prompting Schwartz to call the project “an amazing multicultural collaboration.
Contributing editor Chris Olson, a former editor-in-chief of Building Design+Construction, is based in Traverse City, Mich.