A key reason why buildings are so important for decarbonization is that, according to the Washington Department of Commerce, “buildings represent approximately one-fifth of Washington’s greenhouse gas emissions. This includes emissions related to electric generation. The greatest portion of the sector’s emissions come from the direct combustion of natural gas and other fossil fuels in buildings for space heating, water heating and cooking.” Moreover, the World Economic Forum (WEF) wrote, buildings offer more energy-saving potential than industry or transport.

Energy-efficient buildings create comfortable living conditions with the least possible amount of energy consumption, researchers Janamejay Gupta and Manjari Chakraborty explained. 

The growing impacts of climate change have also made the decarbonization of buildings essential. Making buildings “net zero”, whereby greenhouse gases (GHG) emissions are reduced as close to zero as possible and any remaining emissions are offset, is a key strategy. For houses, Efficiency Vermont said, net zero is the balance between the power a home needs and the renewable energy homeowners can generate to match the need. “With new heating technology and lower-cost renewable energy systems, any home can get to net zero”. Solar is currently the most affordable way to generate energy, while air sealing yields the greatest energy savings and weatherization as well as usage of smart devices establish also reduce energy waste.

A Framework for Building Electrification, Efficiency and Decarbonization in Washington State

Washington is consistently among the top states for energy efficiency policies and programs that save energy, advance equity, and produce environmental and economic benefits, according to the Washington State Department of Commerce. Washington’s 2021 State Energy Strategy identifies energy efficiency in buildings as a core strategy for meeting climate goals. The state’s Clean Buildings Performance Standard is the first in the nation, creating standards for large commercial buildings, and it is a key pillar in securing Washington’s climate goals.

This legislation for buildings will move the state further towards the goals of its Energy Strategy and, at the same time, require significant changes by homeowners, commercial building owners, contractors and developers. Washington Department of Commerce Senior Energy Policy Specialist Liz Reichart explained the changes at the Solar Washington Annual Meeting in January. The goals for the legislation include increasing efficiency and reducing carbon emissions in buildings across the state.

The Department of Commerce did extensive modeling, as part of developing the state energy strategy, to understand scenarios to decarbonize the building sector. The most important takeaway was that a combination of electrification and efficiency were identified as the least cost pathway to achieve the necessary GHG emissions reductions in the building sector. The core of this work is around electrifying buildings and making them more energy efficient. 

This figure from the Department of Commerce illustrates the pace at which high-efficiency electric strategies will need be implemented to reduce emissions from electricity generation to meet the limits set by the 2019 Washington Clean Energy Transformation Act (CETA).

Washington’s energy codes ensure that buildings are built efficiently and that buildings are operating safely, healthfully and affordably.

The energy codes are updated on a three-year cycle, Reichert explained. The 2021 energy codes were delayed and are now scheduled to take effect on March 15, 2024, barring some unexpected event. While they do not ban natural gas, they make electric space and water heating the default.

The Clean Buildings Act that was enacted in 2019 requires that all covered buildings complete energy management, operations and maintenance planning. The largest buildings, which are classified as Tier One buildings and include all commercial structures over 50,000 square feet, must meet the state's clean buildings performance standard by June 2026. A new Tier Two includes buildings between 20,000 and 50,000 square feet as well as multifamily buildings over 20,000 square feet. The first phase for Tier Two buildings focuses on benchmarking, operations, maintenance and reporting. A performance standard for these buildings would only become effective in 2031. The performance standards are based on energy use intensity, Reichart explained, of which energy consumption is a primary piece. Building performance is benchmarked against buildings of similar use types – hospitals compared to hospitals, movie theaters compared to movie theaters- if the building’s energy use intensity is greater than the average EUI target for the state, the building owner then will need to pursue meeting the target.

The State’s Clean Energy Fund is foundational to the deployment and commercialization of new technologies in Washington, Reichert said. This portfolio of grant programs covers modernization, transportation, electrification and more. One program supports the building electrification program, which focuses on innovations for highly efficient electrified buildings. The Department also has a clean buildings incentive program focused on helping buildings covered by the clean buildings performance standards meet their energy use intensity targets. A weatherization program focuses on safety, health and energy efficiency improvements in low-income homes and low-income multifamily buildings. There are also programs aimed at helping public buildings access clean energy and energy efficiency, and a program for home electrification that provides point-of-sale rebates. The state electrification program will also have grants to local governments, tribal entities and small businesses.

While the programs are beneficial, there can be costs. The Washington State Building Code Council (SBCC) adopted rules restricting the use of natural gas or propane appliances to adhere to the goals of building zero fossil-fuel greenhouse gas emission homes and buildings by the year 2031, The Lynnwood Times reported. In a survey by BIAW (Building Industry Association of Washington), the Times noted, builders said the heat pump mandate will increase the cost of a newly constructed home by at least $9,200, with an additional $2,400 for homeowners who install both natural gas or propane and electric appliances.

Solar-specific provisions in the Act

An exciting new development that goes beyond solar readiness is a provision for the installation of solar on new buildings over 10,000 square feet: “Each new building, or addition larger than 10,000 square feet of gross conditioned floor area, shall include a renewable energy generation system consisting of not less than 0.5 W/ft2 or 1.7 Btu/ft2 multiplied by the sum of the gross conditioned floor area.”  

Also, performance standards are based on energy use intensity of which energy consumption is the primary piece.  Onsite solar can essentially be credited essentially 1:1 for lowering a building’s energy use intensity (EUI) – so the onsite solar can make up a piece of a building’s compliance strategy.

Any solar that replaces purchases from the grid directly decreases that building’s EUI. The way the standard is written, it doesn’t matter who the owner of the solar is – the buildings onsite can take credit. The solar doesn’t have to be attached to the building, it can also just be ground mounted and hosted onsite. Additionally, any solar that is sold back to the grid is taken out of consumption, so buildings are also rewarded for providing that generating resource. And as with most performance standards, including the City of Seattle’s, there are no REC purchases allowed. It has to be onsite solar. But the way the standard was designed was first and foremost an energy efficiency and emissions reduction policy, but also one that encourages solar installation.

Practices to Increase Efficiency and Decarbonization

Measures to make a building energy-efficient encompass the building’s entire lifecycle, from construction on through maintenance and demolition. An energy-efficient building balances all aspects of energy use by providing an optimized mix of passive solar–design strategies, energy-efficient equipment and renewable sources of energy. The building remains fully functional and thermally comfortable.

Retrofitting existing buildings could reduce their energy intensity by almost 40 percent, according to the WEF, and making buildings more energy efficient could reduce global energy demand by 12 percent. Retrofitting buildings can also reduce residents and employees’ sickness by 20 percent, improve productivity, create 3.2 million new jobs per year, and increase asset values of buildings by about 15 percent.

Key components of decarbonization and improving energy efficiency include usage of renewable energy such as solar or wind, better insulation, more efficient lighting and new construction materials. Smart thermostats and LED lighting are also beneficial.

Digitalization can also accelerate decarbonization, the UNDP noted. Using an energy management information system (EMIS) that leverages software and technology to monitor, analyze and control a building’s energy use is a best practice. Adding AI capabilities to these smart systems can mine data on energy consumption to influence decision-making for lighting, heating, cooling, and security systems. While energy-efficient systems have significant upfront costs, long-term savings and benefits such as better health make them effective.

In Conclusion

Clean buildings are crucial to meeting our state’s climate goals and investment in building energy efficiency is an effective way to significantly reduce greenhouse gas emissions.  Overall, the new legislation as well as the Clean Energy Fund keeps Washington at the forefront of clean energy initiatives nationally and will provide significant benefits to people as well as the planet.