The variety of technological solutions used to produce “high-performance” commercial building façades are based on fundamental building physics concepts for daylighting, solar heat gain control, ventilation, and space conditioning. The following descriptions of the various advanced building energy-efficiency strategies are therefore related to these fundamental concepts. In isolation, it’s fairly easy to understand the basis and realization of a single given strategy (e.g., daylighting), but designers and engineers typically combine several strategies (daylighting + solar control + ventilation) to achieve high performance. Case studies are given in Section 4 to illustrate how combined strategies are played out in built form.

Automated tubular grid skylight controls daylight at Munich Airport.

The selection of the following technological solutions was made for California-specific cooling-load dominated commercial buildings. For this building type and climate, window solar radiation and conduction heat gains contribute to both total energy use consumption and peak demand. Lighting loads can be offset with daylight in perimeter zones (or skylit in core zones) in this state where sunshine is plentiful. Careful control of these loads can help to significantly reduce annual operating costs and improve occupant comfort. Curtailment of these loads during peak summer mid-day hours can also reduce the need for further generation (power plant) capacity within California and can lower emissions.

Substantial interest in double-skin façades and active façade systems continues to occur in the European Union (EU). Over the 1990s, there has been numerous buildings constructed with complex, interactive building façades, many for which there are few post-occupancy data to confirm that design claims have been successfully realized. It is important to note that while this strategy is discussed in this section, applicability to the California climate may be uncertain. The EU climate is substantially cooler than California and the latitude is higher; the design of these façades may be more applicable to U.S. northern climates. California locations may require a different set of technology and design solutions to meet performance requirements.

Question/Information: eslee@lbl.gov