large rooftop air conditioning equipment

Natural gas-powered HVAC systems are in Boston officials’ and designers’ crosshairs as they look to slash the commercial real estate sector’s carbon emissions.

After imposing carbon emissions-cutting requirements on existing commercial buildings, the city of Boston is planning to add zoning regulations applying to new construction starting in January 2026.

The net zero carbon zoning proposal requires developers to use heating and cooling systems that don’t emit greenhouse gases, such as electric heat pumps and solar arrays, contract with renewable energy providers or submit payments to a city fund. It would apply to all new buildings 20,000 square feet or larger, new buildings with 15 or more housing units, and additions of at least 50,000 square feet.

A real estate industry group said the proposal adds another financial burden on investors.

“As an organization we are committed to lower the carbon footprint of real estate assets, however the more regulatory requirements you put on the development community, the more difficult it is to make the economics of development work,” Greater Boston Real Estate Board CEO Greg Vasil said in a statement. “Increasing the costs of creating buildings makes it more difficult for Boston to compete with other destinations.”

The new zoning would apply to projects approved starting in January 2026. At a virtual meeting last week, Boston Planning & Development Agency officials said the proposed implementation date acknowledges that time is needed for upgrades of the region’s electric grid, and utility companies’ lengthy backlogs for property hookups.

“Yes, this is a lot of electrical load that will be coming online,” said Travis Anderson, the BPDA’s senior infrastructure and energy planner. “We also recognize this will have to be coordinated and planned directly with local utilities.”

Buildings account for more than two-thirds of Boston’s greenhouse gas emissions, according to city climate studies, making large commercial developments a major focus of decarbonization policy. The city is targeting net-zero emissions standards by 2050.

Boston’s Building Emissions Reduction Disclosure Ordinance requires approximately 6,000 of the city’s large buildings to begin reducing carbon emissions on a phased basis through 2050. Landlords can comply by on-site upgrades, purchasing renewable energy contracts, or submitting payments to the city’s equitable emissions investment fund.

The zoning proposal sets less stringent targets for some building categories that produce the most emissions.

Hospitals and manufacturing buildings would be required to meet the 2030 BERDO emissions reduction target in 2026, while lab buildings would be required to meet the 2040 BERDO target in 2026.

Under the new zoning proposal, developers also would be required to submit data on the use of embedded carbon in building materials, an emerging focus of green building regulations.

A public comment runs through May 28, followed by a potential BPDA board vote on June 13.

Boston Proposes 2026 Deadline for Net Zero Developments

by Steve Adams time to read: 2 min