$41/month higher heating costs for 2,500 sq. ft. stretch code compliant home

Reference: RLPNC 17-14: Mini-Split Heat Pump Incremental

Cost Assessment

Cost of electricity in Lexington

Reference: Lexington's Community Choice Program details

Electrification is an affordable alternative to gas in most cases, and in fact is becoming standard for affordable housing and multi-family buildings.

Reference: MassCEC testimony to Brookline on availability of alternatives to gas

Bylaw for Home Rule for Clean Heat would affect an average of 100 buildings max per year, resulting in about 20-22% of total buildings affected by 2050.

Reference: Report on teardown properties by M. Daggett (Comprehensive Plan Committee member), 2019

Heat Pumps

Air source heat pumps (ASHPs) have a COP of 2.5+ even in cold New England winters

Reference: Northeast/Mid-Atlantic Air-Source Heat Pump Market Strategies Report

There are many ccASHPs available, some with extremely high season COP values and that go down to very cold temperatures (-15 F)

Reference: Cold Climate Air Source Heat Pump Product List

The temperature around here never gets cold enough for ccASHPs to not work

Reference: How Cold are Boston Winters?

The Grid

Electrical demand in New England is decreasing, overall and peak demand. Year to year variability is around 1%.

Reference: New England’s Electricity Use

Natural gas generates about 50% of the electricity that we use

Reference: ISO-NE Resource Mix

Electricity emission rate of about 550 lbs/MWh

Reference: New England Electricity Emissions, according to the EPA

Electricity emission rate of about 700 lbs/MWh. Decreased by 200 lbs/MWh over the past decade, or about 20%, and shows no signs of slowing

Reference: ISO-NE 2017 Emissions Report

About 80% of electricity generated within MA is from natural gas

Reference: Massachusetts State Energy Profile

Health & the Environment

CO2 emissions from different fossil fuel sources

Reference: Greenhouse Gases Equivalencies Calculator

Onsite fossil fuel combustions (oil, propane, and gas heating) make up about 36% of the Lexington's GHG emissions

Reference: Lexington Getting to Net Zero Roadmaps (2018) Energy Inventory Report (Peregrine Energy Group prepared for Sustainable Lexington, 2020)

Makeup and percentage renewables for Arlington default electricity

Reference: New England Electricity Emissions, according to the EPA

Portion of residential energy going towards space and water heating is about 75%

Reference: MA Residential Energy Use

We cannot meet our legal obligations for emissions reductions while continuing widespread use of fossil fuels for home heating.

Reference: Massachusetts Gas versus Massachusetts Climate Goals


Besides Home Rule, Incentive Zoning is another tool municipalities use to require buildings to be constructed climate-wise and above the minimum state code.

  1. In Attorney General Office's 7/2020 letter (Case #9725) disapproving Brookline's gas ban, she had the following statement:

  • “If we were permitted to base our determination on policy considerations, we would approve the by-law.”

  • “During the unprecedented reality of climate disruption, the Town has acted in an exemplary manner to attempt a bold step to tackle the problem locally.”

  • “To be sure, even without the by-law, residential and commercial property owners may choose energy systems that do not rely on fossil fuels. And the Town may consider adopting incentive programs to nudge property owners in that direction.”

  1. Legal basis for Brookline's Gas Ban in 2019: Letter to Municipal Law Unit (MLU) in support of Brookline’s Warrant Article 21

  2. MA Incentives and Policies for Sustainable Buildings: Options and Case Studies by RMI:

A. Evidence that Incentive Zoning is legal:

  • Both cities and towns need to comply with state building code

Per AGO Healey’s letter to Brookline: “As such, the Legislature established the Building Code as the one state-wide building code and rejected the premise of each municipality having its own requirements. “All by-laws and ordinances of cities and towns…in conflict with the state building code shall cease to be effective on January [1, 1975].”

  • Cities’ bylaws do not need AGO approval, towns’ do

  • Somerville (city) incentive zoning (2019) has not been challenged by AGO (not considered illegal by AGO)

  • As of today, there have been no incentive zoning bylaws that exceed state building code challenged by AGO

B. Evidence that Incentive Zoning with LEED requirements (higher than state building code) is legal:

  • LEED in incentive zoning:

    • Cambridge

    • Somerville

    • Acton (town, in place since 2004)

  • LEED in overlay district (as incentive):

    • Northampton

    • Somerville (LEED Platinum)

  • LEED in overlay district (not as incentive):

    • Brookline Emerald Island Special District (2016) was disapproved by AGO

  1. MA AGO decision on Brookline zoning bylaw 2017 discussed LEED requirements. Brookline Emerald Island Special District Zoning bylaw proposal.

  2. What is Overlay District in Massachusetts:

  • "An Overlay District is a type of land use zoning district that "lies" on top of the existing zoning and potentially covers many underlying districts or portions thereof. "

  • "Overlay Districts are specified by statute and can be established with either optional or mandatory requirements upon the underlying land."

  • Commercial: under 8.3. OVERLAY DISTRICTS Master Planned Development (MPD), on page 389:

  1. Somerville's incentive zoning bylaw language for commercial zones:

"Development Standards

a. Sustainable Development

i. Laboratory buildings must be LEED Platinum certifiable.

ii. All other building types must meet the following:

a). No on-site combustion for HVAC system operation;

b). No on-site combustion for cooking equipment, excluding Eating & Drinking Establishment principal uses; and

c). Be certifiable as:

i). Zero Carbon or higher from the International Living Future Institute; or

ii). PHIUS+ from the Passive House Institute US.

iii. All new principal building types must include a green roof, photovoltaic (PV) devices, or both for 100% of the roof area not occupied by building systems equipment or required outdoor amenity spaces."

(Somerville is a city, whose zoning bylaw is not subject to Attorney General Office's approval. However both cities and towns must comply with state building code and Somerville zoning bylaw has not been challenged since its establishment in 2019).

  1. Brookline's Warrant Article 25 and Article 26 in 2021 were disapproved by AGO's Municipal Law Unit (MLU) on 2/25/2022 (Case # 10315). We are reviewing this decision.

Example Buildings

Affordable housing is leading the way in terms of electrification, even without laws like this.

Reference: Cambridge’s ‘Passive House’ Is Built With Focus On Affordable Housing, Climate Change

Electric buildings are increasingly the norm for affordable housing and multi-family buildings

Reference: List of example buildings

Landmark Center Phase III Lab buildings with Hybrid HBAC

Alexandria Real Estate presented Life Sciences & Sustainability at Boston Society of Architects in April 2021. (See slides 25 & 26 re clean heat.)

Moderna leases Hybrid lab at 325 Binney - “As part of Moderna’s commitment to sustainability, the high-performance building ... is designed to be the most sustainable commercial lab building in Cambridge. ”

Info on Building Electrification (Clean Heat)

Watch this inspirational 3-minute video

MacArthur Genius Award winner Saul Griffith explains why we need to electrify everything and how we can do it while saving money for everyone.

Do heat pumps work in extreme cold weathers?

Here is a MrCool video explaining how it works!

(The example in the video is a ducted, central heat pump, which works very similarly as a ductless, mini split.)

Can Hybrid HVAC work in lab buildings?

Example of best practices in lab buildings: Sustainability Goals for Ground-up Development of New Buildings by Alexandria Real Estate (ARE)