As mandated in the 2021 Climate Law and the state’s Clean Energy Climate Plan, the Massachusetts residential sector must achieve a 95% reduction in greenhouse gas (GHG) emissions below 1990 levels by the year 2050 and a 50% reduction in GHG emissions by 2030. In order to meet this target, housing units will need to be built or retrofitted to the highest energy efficiency standards, while phasing out fossil-fuel powered systems and equipment (electrification) and deploying renewable energy at scale (greening the grid).
Massachusetts has 3.05 million existing housing units, including a substantial number of older housing units that lack adequate insulation and do not use clean energy sources for heating, hot water, cooking, or other needs. Approximately 22% of occupied housing units rely on oil heating systems, 51% rely on natural gas, and 20% use electricity for home heating. Further, roughly 80% of the buildings that will exist in 2050 have already been built, making retrofits essential to meeting net zero emissions limits. While there is a feasible pathway for decarbonizing newly built housing, retrofitting existing buildings is often more complicated and costly.
As stated in the Commonwealth’s 2023 and 2024 Climate Report Cards and the report from the Commission on Clean Heat, it is critical that the Commonwealth rapidly scale up decarbonization efforts within the residential and commercial building sectors. The report alludes to the need to coordinate actions across multiple fronts including investments in affordable housing and low-to-moderate income communities as well as coordinated utility planning and urban development. The acceleration of decarbonization was central to the funding provided in the Affordable Homes Act, which provided funds for decarbonizing state-aided public housing that serves some of the most vulnerable residents and reauthorized the Climate Ready Housing program that provides funds for retrofitting privately owned affordable housing. The new 2025-27 Qualified Allocation Plan (QAP) further prioritizes the state’s Low-Income Housing Tax Credit equity to prioritize decarbonization by requiring, at minimum, stretch code building energy performance standards for all funded projects and Enterprise Green Communities Certification. The QAP priorities for decarbonization, per the Affordable Homes Act, will also be reflected in state capital grant making for affordable housing production and preservation. Additionally, EOHLC remains committed to working with partners at MassHousing in making key investments through the Climate Bank to increase the supply of decarbonized affordable homes.
The 2025-2027 Mass Save Plan significantly increases financial incentives and technical assistance available for building decarbonization, with specific equity targets and increased support for low- and moderate-income households. EEA has conducted an analysis and is advancing recommendations to further streamline and enhance resources for building decarbonization. Recent successes suggest that under the right circumstances with effective agency coordination, program design, and adequate funding, decarbonization and affordable housing goals can be mutually reinforced. For example, there are over 23,000 multifamily units in the Mass Save new construction program pipeline that meet Passive House standards, the highest level of energy efficiency. This effort has been led by the affordable housing developer community and incentivized by affordable housing tax credits and Mass Save as well as by municipal adoption of the Specialized Energy Code to meet the State's 2030 and 2050 climate mitigation mandates. The Specialized Energy Code which requires Passive House standards for new multifamily housing has been adopted by 48 municipalities covering 30% of state’s population.
In order to reach the Commonwealth’s goals of creating more sustainable housing it is critical to match continued investments with new innovative construction models to build more efficiently and sustainably across all housing development types. This includes building on the ‘thermal code’ approach of the Stretch and Specialized energy codes from the Department of Energy Resources and exploring modular development and offsite construction strategies. The energy codes that were updated in 2023/2024 are a good example of this shift; new requirements to reduce heating and cooling loads (with policies like Passive House and TEDI) will reduce total cost-of-ownership through lower energy costs and also result in a x5 reduction in the ratepayer impact of future electric grid investments.