Energy codes have come a long way since they were first developed in the 1970s. What used to require tedious calculations now can be solved by meeting prescriptive requirements listed in a table. However, while the energy code moved from complex to simple over the years, some would now argue it’s moving back toward the complex side. Under the 2006 International Energy Conservation Code (IECC), the entire residential prescriptive requirements covered just four pages, but the same prescriptive sections in the 2015 IECC occupies eight and a half pages. Is this necessary? If the goal is to make buildings more efficient in the most cost-effective way, shouldn’t the process and requirements be efficient, too?
In a performance that could receive first place for the “Energy Code Nerd Award,” architect Chris Benedict and partner Henry Gifford, a mechanical system designer at Gifford Fuel Saving Inc., unveiled what they dubbed the “Perfect Energy Code” in the recent online video above. They claimed that energy code compliance should require only two numbers:
1. Heating system input / square foot of the building < X
2. Cooling system input / square foot of the building < Y
The energy code would define what target X and Y numbers would be based on for each climate zone; and the building official would only need to verify that the equipment installed meets what was submitted on the plans. Since the building envelope has a direct impact on equipment sizing, this type of plan might work, but Benedict and Gifford leave a gaping hole in their “perfect” code by forgetting to include a requirement for duct and envelope leakage testing. Leakage testing is one of the best quality-control measures builders have in their toolbelts to ensure their trades are providing a quality service and that buildings are not leaking energy. Even the most highly efficient and perfectly sized equipment will waste a lot of energy if the ducts and envelope aren’t properly sealed.
Although the video provides an interesting concept for future iterations of energy codes, it’s not likely to be ushered in through the IECC code development process anytime soon. Looking at some of the more recent changes to energy codes may provide a better indication of where they’re heading. The 2015 IECC includes a new Energy Rating Index (ERI) compliance path which allows builders the maximum design flexibility in achieving energy code compliance. Builders that are already building under RESNET’s Home Energy Rating System (HERS) can simply use it to demonstrate compliance as long as their HERS Index Score meets the maximum ERI score included in the code. For more information on the ERI, see my earlier blog. ERI scores are determined by using an energy model which is referred to as a “modelled performance approach.”
Another big change is to the 2015 International Green Construction Code (IgCC) with the inclusion of an outcome-based compliance path. An outcome-based compliance path uses energy modelling to predict energy consumption, but compliance is determined based on measured energy-use data after the building is completed and occupied. This is referred to as a “measured performance approach.” The code defines the target energy use based on climate zone and building type. Although the IgCC and the outcome-based compliance path don’t apply to single-family residential construction, they are indicative of the trend toward more performance-based compliance, which allows for maximum design flexibility.
A discussion on the future of energy codes wouldn’t be complete without a mention of increasing efficiency. There was an efficiency increase of just over 30% from the 2006 IECC to the 2012 IECC, but from 2012 to 2015 the increase was less than 1%. While it’s unlikely that the IECC will see such significant savings as were achieved between 2006 and 2012, builders can expect that the energy code will include incremental (3% to 5%) savings during each three-year cycle. Builders should also expect to see more flexibility in compliance options. Flexibility may include more options in the prescriptive and performance paths or even an entirely new option such as the “Perfect Energy Code.”
In addition to flexibility in compliance options, builders and their customers can seek tax credits and incentives for complying with the most recent iteration of the energy code. For example, earlier this month California passed a bill ( AB-802), which in part directs the California Public Utilities Commission (CPUC) to “authorize electrical corporations or gas corporations to provide financial incentives, rebates, technical assistance, and support to their customers to increase the energy efficiency of existing buildings based on all estimated energy savings and energy usage reductions, taking into consideration the overall reduction in normalized metered energy consumption as a measure of energy savings.” So now, instead of being required to use incentives for “above-code” renovations, the CPUC can pay utility incentives for retrofitted buildings that simply comply with the Title 24 Energy Code. For additional information about energy efficiency incentives available in your state, visit the Database of State Incentives for Renewables and Efficiency.
What gets included in the next energy code doesn’t happen by chance. The 2018 edition of the IECC will be determined next year. To get more information on the code development process, visit the International Code Council’s website: www.iccsafe.org.