Outcome-Based Energy Codes
Our nation’s current energy codes include structural and enforcement characteristics that limit the ability to achieve significantly more energy savings without major changes. Current energy code strategies consider only a limited number of the factors that impact building energy performance. They don’t address all those elements of design and construction that influence performance, and they don’t address how buildings use energy once completed.
The way in which a building is occupied, operated and maintained has a major impact on annual energy use, something current codes don’t take into account. More importantly, variability of energy performance outcome once the building is completed leads to significant confusion in the market as to just what the code is delivering.
Getting to Performance Outcome Summit
A group of thought leaders from the building industry gathered to examine the opportunities, barriers and next steps that will transition the commercial building industry from estimating energy use, based on models in the design phase, to measuring real performance outcomes, based on actual energy use in an occupied building. The National Institute of Building Sciences (NIBS) and New Buildings Institute (NBI) hosted the event and released the report which summarizes the results of that meeting.
An Outcome-Based Compliance Path for the 2015 IgCC
Cities and states looking at energy efficient buildings to meet energy use reduction goals are getting a boost from the 2015 International Green Construction Code (IgCC). A new section was approved for the energy chapter of the 2015 IgCC. The new outcome-based compliance pathway sets energy use targets by building type and climate zone, with the goal of actually achieving expected energy results rather than relying on prescriptive measures or predicted models that may not yield actual energy savings.
Establishing an Outcome-Based Code
To better align building performance improvement over time with widely accepted policy goals and public expectations, it will be necessary to move to an outcome-based code strategy, one where actual energy use is the metric by which building performance is judged. This approach focuses on real and measurable energy performance improvement rather than on the relationship of the buildings’ energy characteristics compared to a theoretical building built to a code baseline.
By adopting an outcome-based approach to energy code regulation, operational and tenant energy use characteristics become part of the opportunity for reduced building energy use. In fact, improvements in operational practices and tenant behavior can be highly cost effective, even in the absence of specific code targets. Key to the process are:
- Better data about actual building performance. Information about how the building stock is currently performing is sparse. More and better information about building performance must be made available to policymakers, code jurisdictions, and the market so that realistic building performance targets can be set. Some jurisdictions have adopted disclosure ordinances which require building owners to provide current building energy performance information to interested parties in a leasing or sale transaction.
- Adjustable tracking/reporting tools. Tools and methodologies are needed for consistent reporting of performance information. Although better disclosure information may allow jurisdictions to set building performance targets, these targets must account for typical variations in schedule, use and occupant density, and other factors associated with individual building use patterns.
- Commitment and enforcement mechanisms. Current code enforcement strategies generally end at building completion (when the certificate of occupancy is issued). To extend code scope into the operational life of the building, new incentives and enforcement mechanisms must be developed. These may take the form of performance bonds, annual inspections, utility rate accelerators, or other strategies.
- Metering capabilities. To manage operational energy use effectively, building operators and tenants must have access to good information about how the building is performing on an ongoing basis. This implies that various feedback and submetering capabilities must be integrated into the design to enable real-time performance monitoring and response.
Developing Effective Codes and Standards for Net-Zero Energy Buildings, Building Design + Construction, March 2011
Outcome-Based Energy Codes on the Way to Net Zero, white paper by Sean Denniston, Mark Frankel, Dave Hewitt, New Buildings Institute
Outcome-Based Code Summary, New Buildings Institute
Re-Inventing Building Energy Codes as Technology and Market Drivers, A 2010 ACEEE Summer Study Paper examining new trends and opportunities in developing and using codes.
The Future of Energy Codes, A 2010 ACEEE Summer Study Paper looking at the limitations of current code structures and posing questions what the future of codes should look like.
Achieving Energy Performance – Going Beyond Codes and Standards, A comprehensive primer of the history the ASHRAE model codes from inception through current code developments.
Toward a Future Model Energy Code for Existing and Historic
Buildings, A 2010 ACEEE Summer Study Paper examining outcome-based codes specifically in the context of existing buildings.