Energy Code Development Begins: Focus on Residential

This is part one of a two-part series.


Code officials, builders, energy efficiency advocates, and others weighed in this month on proposals to update the next model building energy code–a crucial policy tool for states, counties, and cities as they work to stave off the worst impacts of climate change.  


While the debate at the Committee Action Hearings in held by the International Code Council in Albuquerque was often as spicy as the famous New Mexico chile, the end result leaves us hopeful that the 2021 edition of the International Energy Conservation Code (IECC) will improve energy efficiency for both residential and commercial buildings. Several efficiency improvements were given tentative approval, while the worst of a slew of weakening amendments were rejected.


The IECC, the model energy code recognized by the Department of Energy and cited in federal law, is updated every three years through a stakeholder process. It's then up to local jurisdictions to adopt and enforce the codes.


An improved energy code means buildings that use less energy, which means lower bills for families and businesses and lower carbon pollution from power plants. Furthermore, energy efficient buildings are more resilient: they stay cooler in the summer or warmer in the winter if the power goes out, and they’re more comfortable on even the hottest or coldest days.


NRDC’s goal is to improve the efficiency of the energy code, while ensuring it remains relevant to the needs of local jurisdictions that increasingly are looking for solutions that not only save energy and water, but also cut carbon emissions.


Today we’ll focus on residential proposals, and I’ll be back next week with a focus on proposals that would impact commercial buildings.


How Codes Get Made

We will go into more detail about some of the most impactful proposals below, but first, it’s important to understand the process. NRDC and many others submitted proposals to the International Code Council back in January, offering a variety of ideas for modifying the energy code.


The Committee Action Hearings earlier this month gave proponents and opponents of each proposal the opportunity to hash it out in front of a technical advisory committee, which then voted on each one. But the committee vote is not the end of the process, by far. Next, proponents can revise and resubmit proposals, which will be discussed again during the Public Comment Hearings in October. Governmental voting members like city code officials or sustainability directors have the final word, and they’ll get to vote on each proposal in November. While governmental officials hold the ultimate power on what goes into the new building energy code, the committee’s action is still important: a favorable recommendation means a proposal only needs a simple majority of governmental voting official votes to pass and become part of the code, while a committee recommendation for disapproval means that a proposal requires a two-thirds majority of votes to reverse it to become part of the code.  


Here’s a look at the residential proposals that could have the most impact on the energy efficiency and carbon reduction of the 2021 model energy code.


Residential Proposals

Overall, the committee approved relatively few residential code proposals that will make meaningful efficiency improvements. It has been particularly challenging to make major progress in the residential code for the last few code cycles, due in part to the fact that the ICC reserves four of its eleven voting seats on the committee for representatives of the National Association of Home Builders (NAHB). NAHB tends to oppose any proposals that will increase the first cost of construction, even though efficiency improvements will save consumers far more than they cost over the lifetime of the building. That being said, there were also several knowledgeable efficiency advocates on the committee who made sure the discussion was balanced. In addition, a number of proposals that could have dramatically weakened the code were disapproved. That’s no small victory in and of itself! While it will take a two-thirds voting majority to overturn the committee’s votes, we’re confident that governmental voting members will choose efficiency when they vote in the fall.


Zero-Energy Buildings

NRDC and the New Buildings Institute collaborated on an innovative proposal to create a new, optional appendix for local code adoption that would result in residential buildings which, over the course of a year, would produce as much energy as they consume. This would be achieved through a mix of aggressive, yet achievable, levels of energy efficiency combined with renewable energy like rooftop solar panels. While this proposal had robust support from the efficiency community, code officials, the solar industry, manufacturers, and others, it failed the committee by one vote. But we’re not deterred: we will work with anyone interested to improve the proposal and resubmit it to the public comment process. Many states and cities have carbon reduction and sustainability targets they must meet as part of a state law or local ordinance, and hundreds have signed onto the “We Are Still In” pledge to meet the greenhouse gas emissions reduction goals of the Paris Climate Agreement. Having a ready-made option to adopt clear code language that will require zero-energy use in new homes is critical to making them more energy efficient in a way that can be consistent across jurisdictions, easing the path for builders, code officials, and homebuyers.


Electrification and Electric Vehicles

We’ll also be working to revise proposals that were voted down by the committee related to ensuring buildings are ready to use or switch to electricity rather than fossil fuels for water and space heating (RE147) and ready to charge electric vehicles (RE146 and CE217 Part II). Electrification of buildings and vehicles–with increasingly clean electricity generated from renewable, no-emissions resources–is one of the key policy solutions for tackling climate change, and in new buildings, electrification readiness can be done at a very small incremental cost.


Renewable Energy

A variety of proposals would change the way renewable energy is treated in the code, some of them good, some not so good. We here at NRDC are huge fans of clean, renewable energy–especially when combined with deep levels of energy efficiency. We need more efficiency AND more renewable energy to make our electric grid cleaner, safer, and more reliable. However, it’s not beneficial for renewable energy to take the place of energy efficiency improvements, which is what some proposals recommended. Why? Well, for one thing, even though the cost of renewable energy has dropped dramatically in recent years, energy efficiency is still cheaper for consumers. Putting solar panels on an inefficient home is like pouring water into a container with a hole in it, which takes a lot more effort because the water will leak right out. If a home is made efficient first, a smaller and cheaper renewable energy system can meet your energy demand.


One proposal that did pass, supported by NRDC, is CE263 Part II. It lays out an optional appendix for jurisdictions to adopt if they want to require solar photovoltaic panels. This is a step in the right direction of combining renewable energy AND energy efficiency to achieve a safer, healthier world.



Flexible Code Improvements

There were a few proposals related to improving the energy efficiency of the residential energy code with flexibility for builders, including RE206 and RE209 (from the Energy Efficient Codes Coalition), RE207 (from the Northwest Energy Codes Group) and RE208 (from the Leading Builders of America). They are all structured slightly differently. Notably, the builders’ proposal includes equipment efficiency tradeoffs, which have been voted down again and again by government officials, and the committee had squarely disapproved in an earlier proposal. After several hours of testimony and discussion, the committee took a unique approach by disapproving all of the proposals, but recommending proponents and opponents work together through the ICC’s Sustainability, Energy, and High Performance Building Code Action Committee to develop a solution. NRDC will participate in those discussions and work toward an outcome that improves the efficiency of the code in a way that is practical and feasible.


Water Heating and Water Use

Saving water–especially hot water–saves energy.  In a significant breakthrough this year, the technical committee unanimously approved a proposal developed by codes consultant Gary Klein and supported by NRDC that will give architects and homebuilders an incentive to build homes that reduce the waiting time for hot water, reducing the need to run water down the drain until hot water arrives.  Under this new proposal (RE162), designers will be encouraged to present house plans that place hot water heaters and hot water outlets, such as showers and faucets, closer together, thus shortening the length of pipe in which hot water sits and cools off.  Modelling has found that over 10% of all hot water use is wasted due to the purging of hot water pipes until water is hot enough to use.  After unsuccessful efforts to tackle this problem in the last two code revision cycles, NRDC worked with architects, homebuilders, utilities, and NGO efficiency advocates to win approval for this approach this year.  One contributing factor was the realization that compact hot water distribution will save builders money, as they do not need to buy and install as much pipe.


NRDC is also working to improve water heating equipment requirements in the code (RE126). As building envelopes have gotten tighter in recent years, water heating has made up a greater proportion of energy costs. Though equipment efficiency is generally controlled by the federal government, NRDC’s proposal is structured to improve efficiency while not triggering federal preemption (as states generally can’t set their own standards for equipment which has a federal efficiency), and still providing builders with lots of choices. This is another proposal we’ll be working to improve and modify in the coming months.



Unfortunately, NRDC’s proposal (RE145) to increase lighting efficiency and introduce lighting controls, dimmers, and occupancy sensors into the residential energy code was not recommended for approval. However, we also supported a great proposal from the New Buildings Institute (RE7), which was approved and will increase lighting efficiency. It does not include lighting controls but will achieve much of the same energy savings as NRDC’s proposal by promoting LED bulbs in new homes.



A few proposals related to fenestration (meaning any openings in the building’s envelope, like windows or doors) were recommended for approval by the committee, including RE35, which will save homeowners about one percent in energy costs each year and $275 to $523 over the life of the equipment. This improvement will add no cost to the home in most cases, because windows and doors meeting these requirements are already being used by builders across the country.


We’ll be back soon with a look at commercial proposals.

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