Net Zero Buildings - July 2017

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The Magic of Charrettes In aspiring to reach net zero, ramping down lighting usage is an essential aspect to building design. In fact, effective daylighting can significantly reduce energy use. Design charrettes can help leverage the early design input of daylighting experts—a major asset for net-zero projects.

Barbara HorwitzBennett has been reporting on the architectural industry for the past 15 years. She covers glazing and daylighting for Architectural Products, and in 2011 contributed to an important industry white paper on net-zero buildings.


aylighting and lighting designers preach the importance of their early involvement to ensure design goals. But nowhere is this more critical than with net-zero buildings. Accounting for approximately 30% of a building’s total electricity consumption, not to mention its effect on the cooling load, it’s essential to ramp down lighting usage. “Early daylight analyses help design teams make important decisions at a time when the building design is still flexible and it does not cost significant money in re-design to make big moves,” says Jarret Pearl, project manager, EDI-Integrative Consulting, Albuquerque, N.M., whether it be to optimize orientation, window areas or other forms to support adequate daylight into all areas of a building.

Enter the Design Charrette In order to maximize daylighting design strategy, project teams often utilize design charrettes. “Projects with high performance goals require super-charrettes where all disciplines seek out synergistic opportunities,” says Koti. “Topics such as site, urban agriculture, architecture and solar control, Biophilia and materials figure prominently, to name a few.” After a draft building program has been issued, Brad Pease, AIA, LEED Fellow, LEED AP BD+C, vice president, Paladino and Company, Seattle, explains that his team adds criteria for access to air, daylight and views to each space within the program so the team can begin to

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The fact is that a well-designed daylighting system can reduce energy usage by up to 20%, and when combined with LEDs and photo sensors, those reductions are even more significant. “Early daylighting/lighting studies can inform building/massing for even further energy reductions,” adds Eddy Santosa, lead energy modeler, CallisonRTKL, Seattle. “A daylighting/lighting expert can also assist in identifying space programming strategies and floor plan design.” Part of this process involves setting target illumination levels for each different programmatic space type and identifying the extent to which ambient lighting vs. task lighting will be applied to reach that target. Because lower ambient lighting and customizable task lighting is a key contributor to net-zero projects, this balance is essential, says Ramana Koti, LEED AP BD+C, BEMP, associate, Lord Aeck Sargent, Atlanta.


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