November 10, 2009
by Jessica Sheridan Assoc. AIA LEED AP

(Continued from above)
Lighting Design and the Energy Code
Lighting is one of the ways architects will be most affected by the latest energy codes. However, rather than be limited by the code, architects can use it to design better lighting, claimed Hayden McKay, AIA, FIALD, FIESNA, LEED AP, principal at Horton Lees Brogden Lighting Design. Quality, not quantity, makes a well-lit space, she said. Daylighting, room finishes, natural colors, control of glare and contrast, and light fixtures all help maintain comfortable levels of illumination. Because people spend 85-90% of their lives indoors, McKay also believes a variety of light sources and incorporating daylight can help aid health and preserve circadian rhythms that humans need to stay productive at work. Each space is different and should be lit accordingly, and commissioning controls is key to saving energy.

Mechanical Systems and the Energy Code
While architects may depend on mechanical engineers, it is important they understand mechanical systems, since the majority of the developments in the energy code relate to them, according to John Rundell, LEED AP, of Buro Happold. By understanding how mechanical systems work, architects can develop a dialogue with the engineers from the start of a project. By incorporating more efficiency into their designs, mechanical systems will not have to work overtime to compensate for unnecessary heat exchange.

Building Enclosures and the Energy Code

One way to limit unnecessary heat exchange is with a well-designed envelope. The code relies on thermal resistance of materials (R-value), thermal transmittance of assemblies (U-factor), and solar heat gain (dependent on the Solar Heat Gain Coefficient, or SHGC). Creating air barriers, reducing thermal bridging, using daylighting and natural ventilation, and integrating with the mechanical systems are all strategies for energy-efficient envelope design.

Michael Waite, PE, LEED AP, of Simpson Gumpertz & Heger, suggested using the code as a guideline and reference as early as possible in design. He predicts that in the future the code will require: increased R-values; decreased U-factors and SHGC’s; more air barrier requirements; more restrictions on glazing area; provisions directly related to daylighting; and fleshed-out regulations for variable property materials such as dynamic glazing systems.

Energy Modeling and the Energy Code
While energy modeling may be the most complicated path to take when calculating a building’s performance, it is arguably the most precise way to measure if a building is code compliant, stated Adrian Tuluca, RA, LEED AP, principal at Viridian Energy and Environment. It is also required for buildings with fenestration covering more than 50% of the envelope, or any building that is having difficulty complying with COMcheck or REScheck. If an architect wants to use tradeoffs — a strategy used to offset non-compliant systems with the excess created by high performance systems — then modeling is the best method to use.

Conclusion
Ultimately, energy codes are changing to reflect global climate change and the need to reduce energy consumption. Complying with the latest energy codes will require major adjustments to the way architects currently put together drawings. The energy analysis is just one piece of the puzzle. Support documentation and more elaborate construction documents will become increasingly important as auditing is inevitable. Sustainability is not just important it is becoming a mandate, and the code is just one aspect guiding the way.

Give us feedback on the Energy Code Trainings
AIANY, Urban Green Council, and ASHRAE are gearing up for the second iteration of “Energy Code Changes: What the Design Team Needs to Know.” As the 12.02.09 workshop date approaches (register here), we’d like to hear from attendees to the October/November sessions so we can make the next session even better. Please post your comments to our blog.

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