Assessment
Energy efficiency interventions and electrification of heating and other appliances continue to be the primary methods for reducing emissions from buildings. Massachusetts exceeded its 2025 heat pump installation targets a year early,1 with more than a quarter of those installations fully displacing fossil systems. While total home weatherizations tracked by the state slowed, investments in increased community outreach and contractor capacity are fueling higher demand for home energy assessments, weatherization, and heat pumps among low- and moderate-income customers. Data through 2025 indicate a slower year than 2024 for installed measures, which is typical in the first year of a new Mass Save Plan term as budgets and programs await approval.2, 3 More municipalities are moving beyond the stretch code to the specialized code, reducing residents’ heating needs and adopting electric-ready standards for new construction that drive energy savings. But looking to 2030, the state’s climate plan assumes a faster pace of residential electrification and weatherization than that seen in the first part of this decade.
| Metrics | Submetric | 2023 Report Value | 2024 Report Value | 2025 Report Value | Targets |
|---|---|---|---|---|---|
| Number of households with heat pump installations supported by Mass Save2, 4, 5 | Households with heat pumps as primary heating installed by Mass Save since 20206 | 34,797 cumulative households through 20227 18,362 household installations in 2022 | 63,070 cumulative households through 20237 28,273 household installations in 2023 | 133,753 cumulative households through 2025 40,116 household installations in 2024 30,567 installations in 2025 | The 2025/2030 CECP estimates heat pumps will be installed in at least 100,000 homes between 2020 and 2025 and at least 500,000 homes between 2020 and 2030. |
| Households whose heat pumps fully displaced fossil fuel systems (heat pumps scaled for full heating need) installed by Mass Save | 5,917 households in 20227 | 12,296 households in 2023 | 14,498 households in 2024 12,715 households in 2025 | ||
| Income-eligible households with heat pumps installed in the previous year by Mass Save | 1,069 households in 2022 | 2,592 households in 2023 | 7,126 households in 2024 3,395 households in 2025 | ||
| Number of communities that have adopted the base, stretch, and specialized building energy codes. | Specialized energy code adoption | 25.4% of the population live in these municipalities (31 cities/towns)7 | 29.7% of the population live in these municipalities (48 cities/towns) | 32.5% of the population live in these municipalities (56 cities/towns) | There is no current target for this metric, but increased numbers of communities adopting the stretch and specialized code indicate progress toward highly efficient building envelopes in new construction which reduces impacts to our electric system and reduces energy bills. |
| Stretch energy code adoption | 66.3% of the population live in these municipalities (270 cities/towns) 7 | 61.8% of the population live in these municipalities (252 cities/towns) 7 | 59.9% of the population live in these municipalities (245 cities/towns)8 | ||
| Base energy code adoption | 8.3% of the population live in these municipalities (50 cities/towns) | 8.6% of the population live in these municipalities (51 cities/towns) 7 | 7.7% of the population live in these municipalities (50 cities/towns)9 | ||
| Number of residential energy audits and weatherization projects supported by Mass Save2 | Residential energy audits performed by Mass Save | 100,817 in 2022 | 117,131 in 2023 | 91,606 in 2024 35,291 in 2025 | There is no current target for this metric, but increased numbers indicate reduced total energy use in buildings and may allow for smaller and less expensive heating electrification measures. |
| Residential weatherization projects performed by Mass Save (including income-eligible customers)10 | 40,660 in 20227,10 | 48,012 in 20237,10 | 55,295 in 2024 50,244 in 2025 | ||
| Residential weatherization projects performed for income-eligible customers by Mass Save | 9,179 in 2022 | 11,865 in 2023 | 13,066 in 2024 15,231 in 2025 |
Primary Challenges
- Electrifying existing buildings often requires extensive modifications including electric service and panel upgrades, new ductwork, and ventilation – perennial challenges that are particularly acute for residents with increasingly tight budgets.
- Demand for resources and assistance to support heat pump and weatherization measures exceeds the approved Mass Save budget. Further, federal actions including delays in releasing federal rebate funds and several canceled grants greatly limited the state’s ability to assist residents with financial and technical support.
- Energy efficiency and electrification are lagging in the commercial sector for several reasons, including limited access to upfront capital and need for assistance with long-term planning.
How we are meeting this moment
The Healey-Driscoll Administration has advanced a number of initiatives to support affordable clean heating and cooling. The proposed Energy Affordability, Independence and Innovation Act includes several provisions that remove unnecessary charges from bills and introduce new ways to finance electrification by enabling on-bill financing and lower-cost utility debt financing. It also streamlines Mass Save program delivery and enables more effective deployment of ratepayer resources by consolidating program administrators and procurements, pooling funding, and developing a centralized data platform so that the program can be more strategically targeted to achieve greater benefits. The Home Modernization Navigator and the Massachusetts Energy Savings Finder are new initiatives that make it easier for homeowners and renters to access energy savings opportunities. The new Mass Save three-year plan that kicked off this year invests significantly more in communities that have historically under-participated – specifically renters, low- and moderate-income households, and those who speak languages other than English. New seasonal heat pump electric rates offered by the three largest electric utilities starting in November 2025 are making heat pump adoption more accessible and affordable for households without adding costs to non-heat pump customers. For the first time ever, the state is tracking energy usage in large commercial buildings statewide. Understanding this segment’s usage in depth is an important step for a subsector that represents about 2% of the stock but as much as 40% of overall building energy use and emissions. Commercial building owners will be supported in their decarbonization efforts via the Building Performance Exchange, an effort set to launch this year that will support peer learning, training and research. Updated state energy codes are encouraging grid-friendly Passive House construction and efficient electrification in the multifamily housing and commercial sectors. Over the last twelve months, 93% of multifamily housing units reviewed under the Massachusetts Environmental Permitting Act (MEPA) have committed to Passive House standards which will result in healthier and more comfortable living spaces and lower energy bills for tenants. In addition, 92% of MEPA permitted commercial new construction will have all-electric space and water heating. Lastly, Massachusetts is working closely with utilities to reform grid planning efforts by integrating alternatives to gas like thermal energy networks as a more efficient way to heat buildings.