The Search for Sustainability

As architects search for sustainability in design, it demands a clear understanding of the basic principles of energy conservation. Designers must consider the appropriate use of glazing for the specific environmental challenges of each climate, site, and building design program. Appropriate material selection and sensitive manufacturing processes are considered in product selection. The iterative design process challenges the balance of design aesthetic, building form, window system, opaque envelope, internal loads, building operation, and climate to work in harmony with minimal impact on the environment.

Clerestory windows help provide balanced day lighting. Environmental Experiment Center (EEC) at the Science Museum of Minnesota in St. Paul.

The tenets of sustainable architecture are to integrate environmental technology, resource conservation, and aesthetic design. The ultimate goal, says James Wines in his book Green Architecture will be that a work of architecture "cannot be removed from a particular location without sacrificing its essential meaning…. Environmental thinking means that walls, facades, interior spaces, and the general materiality of a building - outside of their obvious contributions to architectural function - can be seen as much more than physical components in the manipulation of form and space. They become vehicles for the absorption and communication of contextual information. Within this revised perspective, the new environmentalism is as much a social and psychological condition as it is part of an ecological initiative."

It's probable that in the near future, windows will be generating energy for the building in which they are placed. These architectural components will be part of a larger conceptual framework of intelligent buildings. Efforts in this direction are already surfacing.

For the Environmental Experiment Center (EEC) at the Science Museum of Minnesota in St. Paul, the client requested a sustainable-design strategy based on many factors, not the least of which was fenestration. Located a short distance from the Mississippi River, the design is an excellent example of an integrated design methodology. Minneapolis-based Barbour/LaDouceur Design Group bundled several energy-conserving technologies with the careful selection of environmentally friendly products to make the center a model of sustainability.

The client wanted a building "that produced more electricity than it used." Barbour/LaDouceur enlisted the help of "energy allies" - experts in different areas of energy efficiency. The allies include a major Minnesota window manufacturer and The Weidt Group, a Minnesota-based consulting firm that provides sustainable-design assistance for high-performance buildings.

"We believe this building had the potential to actually generate more energy than it required throughout the course of a year," explains Kurt Gough, project architect. The team produced a working model of sustainability, which addressed issues of site, heating and cooling, day lighting and ventilation.

Photovoltaics (PV) on the south-facing roof and a ground-source heat pump system both contribute to reduce the annual energy consumption by 60 percent of code requirements. Double-hung windows balance conduction, solar loss and gain, and day lighting. Photo-sensors dim lights when natural light is available. In addition to the smart use of advanced technology, manually operated windows proved to be an excellent way to control indoor air quality.