In April, the Clean Energy Transition Institute and Poppy Storm of 2050 Institute will release SCALE 2030: Clean Buildings Ecosystem Assessment and SCALE 2030: Clean Buildings Transition Framework. These two papers examine current building stock, energy use, and emissions and propose a framework with five strategies to implement building decarbonization at the necessary pace and scale to reach 2050 net-zero targets for Washington state. In this Deep Dive, we share insights from the Ecosystem Assessment that can inform the state's clean buildings efforts.
Emissions from residential and commercial buildings in Washington increased 62% between 1990 and 2021,¹ as shown in Figure 1. Altering this trajectory to reach net-zero targets by 2050 will be a major change, as indicated by the orange line in Figure 1, which shows target emissions in comparison to the blue line of historical emissions. Residential and commercial buildings together comprise 26% of statewide emissions when accounting for onsite fossil fuel emissions and indirect electricity emissions, which makes them an essential piece of the state’s decarbonization strategy.
The state’s existing building stock offers insights into which focus areas could have an outsized impact on achieving clean buildings. In SCALE 2030, our team proposes eight regions across the state through which clean buildings efforts could be implemented in a tailored way that meets the unique needs of each region (Figure 2). The regions group counties together and encompass entire utility service territories and air quality agencies wherever possible.
Of the eight regions, Puget Sound has the largest concentrations of both housing units and commercial floor area. Over half of the state’s housing units are in the Puget Sound region, as shown in Figure 3.
The Puget Sound region is also home to almost two-thirds of the state’s commercial floor area (Figure 4). Between residential and commercial, the Puget Sound region could accordingly tackle more than half of the state’s clean building transition and be used to pilot and establish strategies that would inform tailored approaches in other regions of the state.
Washington State has a high concentration of single-family and low-rise multifamily homes. Single-family homes are defined in the Northwest Energy Efficiency Alliance’s Residential Building Stock Assessment as detached single-family, townhomes/rowhomes, and homes within two-unit, three-unit, and four-unit buildings. Low-rise multi-family homes are defined as having one to three stories. Combined, these types of homes make up 92% of housing units, shown in Figure 5.
On the commercial side, 75% of all Washington commercial floor area is retail, mixed-use, warehouses, offices, or schools (Figure 6). While all buildings need a path to transition, solutions for these prevalent commercial and residential building types would address a large portion of the clean building transition.
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Electricity and natural gas are the two main forms of energy used in buildings. Residential buildings consume 43% of Washington’s electricity while commercial buildings consume 34%. Together, the two sectors consume 77% of the state’s electricity. Residential and commercial buildings combined comprise 43% of Washington’s total natural gas consumption, making them the state’s largest single end use for natural gas; residential buildings are 25% of natural gas consumption and commercial buildings are 17% (Figure 7).
Achieving Clean Energy Transformation Act (CETA)’s electricity emissions reduction goals will address emissions from electricity use in buildings. Emissions from natural gas use would be eliminated by removing onsite natural gas from buildings, which makes a clean building transition strategy essential for reducing statewide natural gas consumption.
Washington must expand and build upon existing major policies, programs, and market transformation efforts to scale up the clean building transition. Understanding key aspects of the building ecosystem—including distribution, building types, energy use, and emissions—is essential to creating targeted strategies that will successfully decarbonize buildings.
1. Residential and commercial emissions over time were provided to CETI by the Washington State Department of Ecology in January 2025 to provide detail on the Washington State Greenhouse Gas Emission Inventory: 1990-2021.
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