Coverage of fires blazing in unprecedented proportions in the Amazon forests of Brazil has ignited a discussion around the importance of government policies to drive widescale climate change mitigation. Due to their embodied carbon and operational carbon footprints, buildings play a significant role in these efforts, so understanding the impact of legislation on buildings is critical.
This directly translates to building energy codes. In the United States, American Society of Heating, Refrigerating and Air-Conditioning (ASHRAE) and International Code Council (ICC) primarily lead the efforts to develop energy codes, with help from the U.S. Department of Energy (DOE), which most states, cities, or counties in the United States adopt. California is the exception, developing its own building energy code—commonly referred to simply as “Title-24”—that leads the nation in establishing a higher baseline for building energy performance.
And, the result of this baseline? Research by the Pacific Northwest National Laboratory (PNNL) estimates that due to continuously improving building energy codes, homes and businesses in the U.S. will save approximately $126 Billion in energy savings between 2012 and 2040, which is equivalent to around 841 million tons of avoided CO2 emissions.
That’s no small chunk of change (or climate mitigation impact). To keep up, this article shares different approaches to utilizing code to enhance your building’s energy performance, as well as what to expect for the future of energy code.
How to approach compliance
Most high-performance building certifications and city codes use ASHRAE and ICC’s building codes to define energy performance requirements within their rating systems. For example, LEED v4 refers to ASHRAE standard 90.1-2010 Appendix-G requirements as its baseline in the Energy and Atmosphere category and the city of Denver refers to the International Energy Conservation Code (IECC) 2015 developed by ICC for baseline energy requirements for the city’s building energy code.
As these certification programs have gained global visibility, they’ve inspired a whole generation of energy professionals to dive into building performance to make a positive impact. There are two methodologies for code compliance: Prescriptive and Performance.
Compliance to building energy codes is typically overseen by local building permit offices at the city level who first review plans to ensure that buildings comply with the code requirements regardless of which path is pursued. While both are sound approaches to code compliance, projects that invest in high performance energy systems that are usually more expensive can take advantage of the trade-off between energy efficiency measures to save on some first costs.
For example, an office building project that invests in a high efficiency LED lighting system that performs much better than code baseline lighting requirements can make up for some of this additional upfront cost by installing a cheaper, less efficient envelope. In this case, an energy model is used to document the savings of the aggregated energy performance of the design over the code baseline. When projects pursue this method of code compliance, the code compliance energy model that is developed can also be used to further optimize the energy performance. Projects pursuing code compliance through the prescriptive method must document compliance of every energy system (envelope, lighting, HVAC, etc.) to the code, but not the aggregated energy performance of the design.
What to expect from future building energy codes
Building energy code cycles are continuously improving, with a new iteration released every three years. Every consecutive version of these codes has helped raise the energy performance bar for buildings over the years. The graph below depicts the progress made by building energy codes through 2012.
California has been a leader in adopting stringent performance requirements for buildings resulting in efficiency improvements even greater than those shown above, and sustainability policies adopted in California have historically helped steer the building performance requirements for the rest of the country. On the cusp of adoption on January 1, 2020, the 2019 version of Title-24 gives us a sneak peek at the road map for building energy codes in the coming years. It has some exciting updates that have been designed to further push the envelope (pun intended) of high performing buildings on several fronts:
#1: Focus on health and wellness of occupants
Most high performance designers in the energy efficiency industry have largely overlooked occupant health and wellness until recently, but are slowly starting to address it thanks to more research in the area. Title-24-2019 mandates the use of high efficiency air filtration for air handling units for both residential and non-residential buildings to improve indoor air quality, which has a major impact on occupant health.
This will especially benefit future high-rise multi-family buildings. Natural ventilation through operable windows has been a common ventilation strategy for high-rise residential buildings in California. For areas with high concentrations of air pollutants in urban areas or during natural disasters, this means occupants can be exposed to harmful pollutants. Once Title-24-2019 is enforced, multi-family buildings will no longer be able to use natural ventilation, protecting the health of building occupants.
#2: Focus on integration of renewables (on-site and off-site)
Integrating renewable energy sources is one of the most effective ways to achieve high performance buildings. The cost of the technology that enables renewables integration has recently decreased, allowing utility-wide integration of renewables to become commonplace, especially in California. Title-24-2019 encourages new residential projects to adopt demand-response solutions such as battery storage and heat pump water heaters to maintain the baseline load of the utility grids. On the other hand, the code also encourages residential projects to install solar photovoltaic systems to lower the electricity demand.
Going a step further than this, the city of Berkeley recently passed the nation’s first all-electric ordinance that mandates all new construction projects beginning January 1, 2020 to be built all-electric. It likely won’t be the last, as more and more Bay Area cities—from San Jose, to Santa Rosa, to San Francisco—are considering the move away from natural gas. This is big, as Lawrence Berkeley National Laboratory has identified electrification of buildings as one of the most effective ways to cut carbon emissions.
#3: (Re)focus on energy demand reduction
Reduced energy usage is a critical way for buildings to positively influence climate change. The insulation requirements for walls, attics, and windows in residential buildings have been updated in Title-24-2019 to ensure better thermal isolation of indoor from outdoor environments. The interior and exterior lighting requirements have also been updated in the code to ensure high-efficiency lighting fixtures are used.
According to the California Energy Commission (CEC), these updates to the code are expected to result in homes built under the 2019 standard using 53% less energy than those built under the 2016 standard. For non-residential buildings, the savings are about 30% compared to the 2016 code cycle and are mainly a result of lighting upgrades.
What you can do about it
The responsibility to create better buildings rests with all teams involved in a construction project. While energy codes provide baseline guidelines for the energy efficiency of buildings, project teams can choose to go further to reduce the carbon footprint of buildings and realize greater energy cost savings. As next generation’s leader Greta Thunberg said in her speech at the UK parliament:
“We should no longer ask, ‘Have we got enough money to go through with this?’ But also, ‘Have we got enough of the carbon budget to spare to go through with this?’”
Reach out to the stok team to discuss how your project can meet or exceed energy code requirements!
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