There is little consistent data on the overall performance of building facades, and considerable misunderstanding about critical parameters influencing facade performance.
In November 2004, the CIBSE (Chartered Institution of Building Services Engineers) published a new guide advising on the environmental performance of highly glazed facades. TM35: Environmental Performance Toolkit for Glazed Facades is the culmination of a two-year Partners in Innovation project, coordinated by FaberMaunsell and sponsored by the Department of Trade and Industry.
Performance indicators for different facade characteristics are represented, including:
solar energy penetration and solar shading;
occupant visual comfort, including daylight availability and visual engagement;
acoustic attenuation properties; and l estimated manufacturing/installation costs.
Research with architects and designers about advanced facades showed performance is looked at from the glazing perspective, frequently ignoring crucial factors such as frame and edge technologies. This is because readily available data is related to components, rather than complete facade systems.
The report provides a comprehensive database of environmental performances of existing and advanced glazed facades, making it useful during early design stages when irreversible decisions are being made. The guide comes with a CD-based Facade Selector programme, which will access, interrogate and compare simulation results to identify options taking into account peak heating/cooling loads, daylight availability, facade orientations and costs. The software works from a database of 37 facade configurations picked to cover different glazing systems in the market, from basic double-glazed systems to advanced triple-glazed systems, ventilation doubleskinned curtain walls and shading solutions like external overhangs, louvres, fins, and internal or interstitial blinds.
TM35: Environmental Performance Toolkit for Glazed Facades is available from CIBSE, priced £32.90 for members and £65.80 for non-members. Visit www.CIBSE. org for further details.