Washington will require all-electric space and water heating in new commercial and multifamily construction, making it the first state to incorporate building electrification mandates into statewide energy codes.

On April 22, the Washington State Building Code Council, or SBCC, voted 11-3 to include the mandates in an update to the state's commercial energy code. The council also advanced proposals that would restrict fossil fuel use in residential buildings, which would go into effect in 2023 alongside the commercial code updates.

The vote is a milestone for building electrification advocates, who have worked to restrict natural gas use in buildings in towns, cities and counties in several states since 2019. Washington Gov. Jay Inslee has targeted the decarbonization of the state's building sector, which was the state's fastest-growing source of greenhouse gas emissions between 1990 and 2015, according to Inslee's administration.

"A strong energy code is a critical tool to ensure buildings are part of the climate solution, and Washington's new energy code can be a model for other states," said Rachel Koller, a coordinator for Shift Zero, a building decarbonization alliance that advocated for the code changes, in an April 22 statement.

State codes build on local electrification movement

The updates to the 2021 Washington State Energy Code will require builders to install electric heat pumps for space and water heating in most new commercial buildings and multifamily residences with four or more floors. Heat pumps use electric power to move heat from the air or ground to condition indoor spaces. Electric heat pumps are typically two to four times more energy efficient than standard gas heating equipment.

Environmental sustainability group RMI proposed the updates based on Seattle's update to its 2018 municipal energy code. Seattle amended the state commercial energy code in 2021 to largely ban fossil fuel combustion and electric resistance space heating systems. It additionally required heat pump water heaters in new multifamily buildings and hotels.

The SBCC approved a substantial last-minute amendment to the state code updates that would only require developers to meet 50% of water heating capacity with heat pumps. By allowing fossil fuel combustion in new buildings, the amendment would reduce the provision's energy efficiency and emissions reductions but lower the upfront cost to builders, said Caroline Traube, vice chair of the SBCC's Mechanical Code Technical Advisory Group, who proposed the change.

The heat pump requirements will reduce carbon emissions by more than 8 million tons by 2050, according to projections by RMI. The space heating requirement accounts for the majority of the reduction, said Jonny Kocher, a senior associate with RMI's Carbon-Free Buildings Program, in an interview.

Council opens path to residential electrification

The SBCC also sent several proposals requiring heat pumps in residential buildings to technical advisory groups for review. If adopted, the mandates would be significant because cities do not have the authority to amend the state residential energy code, which covers single-family homes and multifamily buildings with up to three floors.

One proposal would require all-electric systems and appliances and prohibit fossil fuel piping in new homes. The proposal, submitted by New Buildings Institute, would cover not only space and water heating but also cooking and clothes drying. The group submitted separate code update proposals that would more narrowly require heat pumps for space and water heating.

Washington Physicians for Social Responsibility submitted two proposals to require stricter ventilation requirements for gas stoves in residences. Research has linked combusting gas for cooking with respiratory illness.

Washington code update stirs debate

Washington gas distributors criticized the electrification requirements in the commercial code for prohibiting the use of high-efficiency gas heat pumps. The mandates would also jeopardize the opportunity to use gas distribution systems to transport renewable natural gas and low-carbon hydrogen, according to Northwest Natural Gas Co., Puget Sound Energy Inc., Avista Corp. and Cascade Natural Gas Corp.

"Enacting these limiting, technology-reductive proposals will damage equity, threaten regional energy reliability and contradict Washington law that protects consumer energy choices," the utilities said in a March 11 letter to SBCC.

During the April 22 meeting, Republican council members put forward several resolutions to delay adoption of the commercial code updates over procedural issues, including inadequate economic analysis and equity studies. Several council members accused their GOP colleagues of seeking to delay the vote. Kocher said the resolutions could form the basis of a legal challenge to the code update.

Resolutions to remove the electrification proposals, introduced by a representative for Seattle's plumbers and pipefitters union, led to nearly an hour of debate. United Association Local 32 business agent Corey Wilker said state legislation that would have mandated building electrification failed to advance in 2021.

"I believe restricting energy sources is an overreach of the duties of this council," Wilker said. "If this proposal moves forward, we're using rulemaking to legislate. That is legislation without representation."

Code council aims to hit energy efficiency targets

Proponents said the proposals would help the SBCC meet a mandate from the state legislature to improve energy efficiency in each three-year code cycle. Washington state law requires the council to adopt energy code updates that reduce annual net energy consumption in buildings by 70% from 2006 levels by 2031.

"This isn't an attack on gas," said Kjell Anderson, an architectural design professional who chairs SBCC's Energy Code Technical Advisory Group. "In order to hit our efficiency targets, we need to move to heat pumps."

Every three years, Washington adopts new energy efficiency standards based on the International Energy Conservation Code. Washington solicits proposals to amend those model codes, and the SBCC facilitates public comment, refines the proposals and ultimately votes on them. The electrification proposals elicited thousands of public responses, with roughly 5,000 letters in support outnumbering about 1,400 in opposition, according to Anderson.

Other states have also looked to building code updates to drive electrification. California established energy budgets based on heat pump technology in its 2022 Building Energy Efficiency Standards, incentivizing builders to build all-electric. New York policymakers are considering electrification mandates to align future building code updates with state climate law.

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