Proving Performance in the IgCC

Dave Hewitt's picture

Will the IgCC allow for higher innovation in building design? An outcome-based compliance path would pave the way for use of advanced strategies. Local code officials will once again find themselves at the nexus of something historic when they come together in Phoenix this week to consider and vote on the first-ever model green code, the International Green Construction Code (IgCC). For the vast majority who don’t follow energy code development, these are the same men and women who showed extraordinary leadership when they gathered last fall and approved  significant increases in energy efficiency for the International Energy Conservation Code (IECC).

The IgCC acts as an overlay code building on the IECC requirements adding stringency for energy efficiency and new rules for water use, materials and other features relative to sustainable building practices. There is much to learn and understand about the IgCC, but one aspect in particular has become a focus of interest to a broad-based coalition of organizations including New Buildings Institute (NBI), The American Institute of Architects (AIA), the Building Owners and Managers Association (BOMA) International, the U.S. Department of Energy and the National Trust for Historic Preservation. These entities have joined together to propose an optional and alternate outcome-based compliance path that would facilitate innovation in building design by setting energy use targets for many building types and allowing those projects to comply by demonstrating actual post-occupancy performance.

What is outcome-based compliance and why is it necessary?

Given today’s code framework, it can be challenging for building owners and designers to push the innovation envelope on energy performance in commercial buildings—not only in terms of cost, but also time.  This is largely due to the structure of current building codes, which have historically been prescriptive in nature. Any deviation requires the design team get a variance, resulting in delays and additional expense.

An outcome-based compliance path would provide a regulatory structure that gives motivated communities, architects, engineers and owners the freedom to employ proven, but more advanced design strategies and technologies offering higher efficiencies than today’s common practice.
That’s precisely why The American Institute of Architects wants it. “The AIA believes that an advanced and green code by its nature should offer the freedom for maximum design innovation and performance potential—and the optional outcome-based compliance path ensures this. Why limit the growing number of innovative design teams, builders, and owners to the minimum performance requirements of even the IgCC,” says Jessyca Henderson of the AIA.

So how does it work?

The outcome-based compliance path would allow owners to comply by providing 12 months of metered data within the first three years of occupancy to prove actual (or outcome-based) energy performance. Targets for energy use would be set depending on climate and building type.  Once the data is collected, the design team—architect, engineer, developer, contractor and owner—would then file a Certificate of Acceptance with the jurisdiction verifying actual performance.

What are the arguments against an outcome-based option?                                    

Some have expressed reservations about an outcome-based compliance path in the IgCC. They worry that all buildings will be required to comply this way or that we don’t know enough to design energy use in a building to a particular target. Neither concern is valid.

An outcome-based approach is not for everyone, nor is it appropriate for every project or every jurisdiction. That’s why our coalition is proposing the path be an optional choice for jurisdictions when adopting the IgCC and offered as an alternative to the other two compliance options described in the IgCC—prescriptive and performance-based (i.e., modeled energy performance). Only those communities and design teams wishing to pursue and outcome-based compliance path would do so.

Also, qualified design teams and builders do understand how to create commercial buildings that perform to the energy performance targets proposed for the IgCC. We know this because many buildings currently in operation surpass those targets.

A green code by nature should maximize design innovation and performance potential. The outcome-based compliance path proposed for the IgCC provides an opportunity to strive for performance goals beyond the minimum threshold established by code. It’s now in the hands of local code officials to decide whether the IgCC will be a standard for innovation or simply the minimum allowed.

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