General Services Administration Regional Field OfficeEdit profile
The design of the new 275,000-square-foot General Services Administration (GSA) Office Building in Houston, Texas, is generated by careful integration of concerns for security, sustainability, and appropriate image into a thoroughly synthesized design solution. Rather than viewing these as independent design parameters, this project addresses multiple issues concurrently and accomplishes a broad range of goals seamlessly and economically. A lightweight metal frame was hung off of the very capable concrete walls to carry a “second skin` for the building. Heavily fritted laminated glass is attached to the lightweight frame with stainless steel clips. The almost opaque glass, which is placed away from the actual thermal wall of the building, shades the structure substantially from direct heat gain from the hot Texas sun. The space between the two skins becomes a significantly cooled microclimate reducing the load requirements for air conditioning systems. Apertures in the glass skin, sized somewhat smaller than the actual windows, are carefully placed to provide excellent day-lighting with reduced glare for interior work spaces. The concrete walls are sheathed in aluminum shingles that both reflect heat and allow the high thermal mass of the concrete to benefit the temperature stability of the structure. The high performance skin of the building is also employed as a major image generator. Because of the depth and richness of the building’s surface its massing could be kept very simple and economical. The aluminum shingles provide a bright, neutral backdrop on which to project the constantly changing light and shadow patterns from the glass skin. Colored a deep, rich green, the glass mutes the bright sun and lends it a subtle hue. In the lush green context of suburban Houston the color of the building feels natural and integral. Tall cottonweed trees near the building on the south side complement the colors and delicate articulation of its surface. The north side of the building, where no sun protection is necessary, has no “second skin.` The aluminum surface is fully revealed and is animated by varied window patterns reflecting the extremely divergent view and lighting requirements of functions on this face of the building. Sustainable Design Aspects Targeting LEED certification, the GSA building has been carefully designed to maximize environmental sensitivity, promote daylighting and views, and provide for the potential of solar energy capture. • The buildings and paved areas are carefully located to preserve several stands of existing trees. • Cut and fill of earthwork has been balanced; swales and berms are located in such a way as to minimize erosion and runoff. • The office building maximizes daylighting by design: o The plan is purposefully narrow, presenting broad faces to the south and north, and thin faces to the east and west. o The windows are oversized, nearly 9’ high. • Other sustainable design elements and building strategies that this project employs include: o Site selection adjacent to mass transit facilities and above the 500-year floodplain o Bicycle storage and changing facilities o Reduction of heat islands via the use of covered parking o Elimination of visual light pollution by careful specification and location of light fixtures o Water efficiency through the selection and use of drought-hardy landscaping, rainwater harvesting, low-usage plumbing fixtures and cooling tower water recycling o Reduction of energy costs through the use of high-performance glass, high insulation values, dedicated energy recovery units, and special selection and design integration of energy efficient HVAC systems, including a full building under-floor HVAC system o Specification and design that integrate a high percentage of recycled and locally harvested materials o Exceptional indoor environmental quality that includes CO2 monitoring and low VOCs for all interior materials o Daylighting and views provided to nearly all work areas through careful design of building floor plate, window size, high floor-to-ceiling height, and careful interior space planning o Substrate for future thin-film photovoltaic application (at the discretion of the owner) provided by the screenwall system By integrating concerns for function, technical performance, and mission-specific requirements into well-synthesized holistic design solutions, the GSA office building creates a simple, elegant, and economical building well-suited to its specific purpose and the goals of its agency. Microclimate Created by “Second Skin` Conceptually dual-layered glass facades allow natural ventilation airflow between the primary building and exoskeleton where warmer air rises up and out the top opening between facades. The large space between the primary face and the exoskeleton also constitutes a shading device for punched vision windows. During schematic design sun angles were analyzed optimizing distance between facades. The exoskeleton dual façade concept is extensively used in Europe and assists in controlling work environment temperatures which can eliminate "sick-building syndrome," that may result from over use of air-conditioning. In winter, the glass layers enhance the heat-insulating functions of the facade owing to the comparatively higher surface temperatures of the inner surface of the facade. Studies estimated by environmental engineers, indicate some ventilated facades show energy savings of 30 to 50 percent and improve urban sound insulation. This green floating glazed facade aesthetically conveys a sense of weightlessness that a conventional solid wall cannot. For building occupants, vision glazing admits copious quantities of light and a broader sense of the outdoor landscape, providing a safe and healthy working environment and blending into surrounding landscape. Note: Due to the highly secure nature f this project, detailed floor plans and sections are not allowed to be shown.