COMMONWEALTH OF MASSACHUSETTS
EXECUTIVE OFFICE OF
ENERGY AND ENVIRONMENTAL AFFAIRS
DEPARTMENT OF ENERGY RESOURCES
100 CAMBRIDGE ST., 9th FLOOR
BOSTON, MA 02114
Telephone: 617-626-7300
Maura T. Healey Rebecca L. Tepper
Governor Secretary
Kimberley Driscoll Elizabeth Mahony
Lt. Governor Commissioner
VIA EMAIL AND HAND DELIVERY
November 14, 2024
TO: Clerk of the House of Representatives
CC: Chairs of the Joint Committee on Telecommunications, Utilities, and Energy
RE: Submission of Stretch and Specialized Code Regulations (225 CMR 22.00 and 23.00)
Dear Clerk:
Pursuant to M.G.L. Chapter 25A, Section 12 (Section 12), please find enclosed:
• 225 CMR 22.00 – MASSACHUSETTS STRETCH CODE AND SPECIALIZED CODE
FOR LOW-RISE RESIDENTIAL – 2024 RESIDENTIAL LOW-RISE
AMENDMENTS TO IECC2021 AND IRC 2021 CHAPTER 11: ENERGY EFFICIENCY;
• 225 CMR 23.00 - MASSACHUSETTS STRETCH CODE AND SPECIALIZED CODE
FOR COMMERCIAL, MULTI-FAMILY AND ALL OTHER CONSTRUCTION –
2024 AMENDMENTS TO IECC2021 AND ASHRAE STANDARD 90.1-2019;
• Summary of the proposed regulations in layman's terms.
In the development of amendments to 225 CMR 22.00 and 23.00, the pertinent provisions of
Chapter 30A, except section five, have been complied with.
In addition to the requirements of Section 12, the Department of Energy Resources has made
additional information available to the public regarding these proposed regulations. That
information is accessible through the Department’s website:
https://www.mass.gov/info-details/stretch-energy-code-development
Please direct questions and comments on these proposed regulations to:
Maliha Khan
Government Affairs Manager
Legislative Director 857-286-0690
maliha.khan@mass.gov
Sincerely,
Elizabeth Mahony
Commissioner, Department of Energy Resources
Enclosures
Layman’s Summary of Proposed 225 CMR 22.00 and 23.00
In December 2022, an updated Stretch Energy Code (Stretch Code) and a new Municipal
Opt-in Specialized Code (Specialized Code) were published in 225 CMR 22.00 and 225 CMR
23.00. CMR 22.00 covers Residential low-rise construction and CMR 23.00 covers Commercial
and all other construction (including most multi-family).
After a year and a half of working with these new regulations, DOER has received a
significant volume of detailed and helpful feedback from regulated entities, building officials and
the design and construction industry. To ensure a broad range of feedback DOER hosted a public
listening session and public comment period in March and April, then again in September after
the draft regulations were issued. The DOER has been taking feedback and questions on a
rolling-basis through the StretchCode@mass.gov mailbox. Based on this collective input, DOER
is proposing modest revisions to the Stretch and Specialized Codes. Some of the topics included
in this revision include a passive house certification process, modification of the requirements for
district energy systems, a number of technical edits requested by stakeholders, and the inclusion
of additional context from the 2021 International Energy Conservation Code to improve the
readability of the regulations.
 HOUSE . . . . . . . . . . . . . . . No. 5122
Communication from the Department of Energy Resources of the Executive Office of Energy
and Environmental Affairs (under the provisions of section 12 of Chapter 25A of the General
Laws) submitting proposed amendments to regulations 225 CMR 22.00 and 23.00 – governing
the Stretch and Specialized Code Regulations. Telecommunications, Utilities and Energy.
The Commonwealth of Massachusetts
_______________
In the One Hundred and Ninety-Third General Court
(2023-2024)
_______________
1 CMR 22.00: MASSACHUSETTS STRETCH CODE AND SPECIALIZED CODE
2 FOR LOW-RISE RESIDENTIAL – 2024 RESIDENTIAL LOW-
3 RISE AMENDMENTS TO IECC2021 AND IRC 2021 CHAPTER 11:
4 ENERGY EFFICIENCY
5 (Note: please see 225 CMR 23.00 for Commercial, Multi-family and all other construction)
6
7
8 Chapter 1: [RE] SCOPE AND ADMINISTRATION
9
10 SECTION R103 CONSTRUCTION DOCUMENTS
11
12 R103.2 Revise Section R103.2 as follows:
13 R103.2 Information on construction documents. Construction documents shall be drawn to
14 scale on suitable material. Electronic media documents are permitted to be submitted where
15 approved by the code official. Construction documents shall be of sufficient clarity to indicate
16 the location, nature and extent of the work proposed, and show in sufficient detail pertinent data
17 and features of the building, systems and equipment as herein governed. Details shall include the
18 following as applicable:
19 1. Energy compliance path.
20 2. Insulation materials and their R-values.
21 3. Fenestration U-factors and solar heat gain coefficients (SHGC).
22 4. Area-weighted U-factor and solar heat gain coefficients (SHGC) calculations.
23 5. Mechanical system design criteria.
24 6. Mechanical and service water-heating systems and equipment types, sizes and
25 efficiencies.
26 7. Equipment and system controls.
27 8. Duct sealing, duct and pipe insulation and location.
28 9. Air sealing details.
29 10. EV Ready Space locations per R404.4.
30 11. Solar-Ready Zone in accordance with Appendix RB, or Solar Zone Area when
31 complying with Appendix RC for mixed-fuel buildings.
32
33 Chapter 2: [RE] DEFINITIONS
34
35 SECTION R202 GENERAL DEFINITIONS
36 R202 Add the following definitions:
37 ALL-ELECTRIC BUILDING. A building with no on-site combustion equipment for fossil fuel
38 use or capacity including fossil fuel use in space heating, water heating, cooking, or drying
39 appliances.
40
41 CLEAN BIOMASS HEATING SYSTEM. Wood-pellet fired central boilers and furnaces
42 where the equipment has a thermal efficiency rating of 85% (higher heating value) or greater;
43 and a particulate matter emissions rating of no more than 0.08 lb. PM2.5/MMBtu heat output.
44
45 COMBUSTION EQUIPMENT. Any equipment or appliance used for space heating, service
46 water heating, cooking, clothes drying and/or lighting that can use fuel gas, fuel oil or solid fuel
47 and that is not a clean biomass heating system.
48 ELECTRIC VEHICLE. An automotive-type vehicle for on-road use, such as passenger
49 automobiles, buses, trucks, vans, neighborhood electric vehicles, electric motorcycles, and the
50 like, primarily powered by an electric motor that draws current from a rechargeable storage
51 battery, fuel cell, photovoltaic array, or other source of electric current.
52 Informational Note: defined as in 527 CMR 12.00: Massachusetts Electrical Code
53 (Amendments) section 625.2.
54
55 ELECTRIC VEHICLE SUPPLY EQUIPMENT (EVSE). The conductors, including the
56 ungrounded, grounded, and equipment grounding conductors, and the Electric Vehicle
57 connectors, attachment plugs, and all other fittings, devices, power outlets, or apparatus installed
58 specifically for the purpose of transferring energy between the premises wiring and the Electric
59 Vehicle.
60 Informational Note: defined as in 527 CMR 12.00: Massachusetts Electrical Code
61 (Amendments) section 625.2.
62
63 ELECTRIC VEHICLE READY PARKING SPACE (“EV Ready Space”). A designated
64 parking space which is provided with wiring and electrical service sufficient to provide AC level
65 II or equivalent EV charging, as defined by Standard SAE J1772 or SAE J3400 for EVSE servicing
66 light duty Electric Vehicles.
67
68 ENTHALPY RECOVERY RATIO. The ratio of change in enthalpy of the entering supply
69 airflow and the leaving supply airflow to the difference in enthalpy between the entering supply
70 airflow and the entering exhaust airflow, with no adjustment to account for that portion of the
71 psychrometric change in the leaving supply airflow that is the result of leakage of entering
72 exhaust airflow rather than exchange of heat or moisture between the airstreams.
73
74 HIGH-EFFICACY LAMPS. Light-emitting diode (LED) lamps with an efficacy of not less
75 than the following:
76 1. 60 lumens per watt for lamps over 40 watts.
77 2. 50 lumens per watt for lamps over 15 watts to 40 watts.
78 3. 45 lumens per watt for lamps 15 watts or less.
79
80 MIXED-FUEL BUILDING. A building that contains combustion equipment or includes piping
81 for such equipment.
82
83 POTENTIAL SOLAR ZONE AREA. The combined area of any low-sloped roofs and any
84 steep-sloped roofs oriented between 90 degrees and 300 degrees of true north where the annual
85 solar access is 70% or greater. Annual solar access is the ratio of “annual solar insolation with
86 shade” to the “annual solar insolation without shade”. Shading from obstructions located on the
87 roof or any other part of the building shall not be included in the determination of annual solar
88 access.
89 SENSIBLE RECOVERY EFFICIENCY. The net sensible energy recovered by the supply
90 airstream as adjusted by any supply fan energy, energy consumption of other equipment
91 transferring heat to/from the supply airstream, case heat loss or heat gain, air leakage, airflow
92 mass imbalance between the two airstreams, and the energy used for defrost, as a percent of the
93 sum of the potential sensible energy that could be recovered from ambient conditions, the
94 exhaust fan energy, and the energy consumption of any other equipment transferring heat
95 to/from the exhaust airstream.
96 Chapter 3: [RE] GENERAL REQUIREMENTS
97
98 SECTION R301 CLIMATE ZONES
99
100 R301 Replace Section R301 as follows:
101
102 R301.1 General. Massachusetts is in climate zone 5A
103
104 Chapter 4: [RE] RESIDENTIAL ENERGY EFFICIENCY
105
106 SECTION R401 GENERAL
107
108 R401 Revise Section R401 as follows:
109
110 R401.1 Scope. This chapter applies to residential buildings. Municipalities which have adopted
111 the Stretch Energy Code shall use the energy efficiency requirements of this chapter, or
112 Appendix AJ or Chapter 51 where applicable for existing buildings. Municipalities which have
113 adopted the Municipal Opt-in Specialized Stretch energy code shall comply with R401.2.4
114 including both the requirements of Appendix RC and this chapter.
115
116 R401.2 Application. Residential buildings shall comply with Section R401.2.5 and either
117 Sections R401.2.2, R401.2.3 or R401.2.4. R-use buildings without individually separate
118 dwelling units (such as single-room occupancy buildings) may comply with Section R401.2.1.
119 The option selected for compliance shall be identified in the certificate required by Section
120 R401.3.
121 Exception: Additions under 1,000 sf shall comply with the requirements of Sections R402,
122 R403, and R404. Level 1 and Level 2 alterations, and repairs to existing buildings, shall comply
123 with Chapter 5 [RE].
124 R401.2.1 Prescriptive Compliance option.
125 The Prescriptive Compliance option requires compliance with Sections R401.2.5 through R404
126 and R408.
127
128 R401.2.2 Passive House Building Certification option.
129 The Passive House Building Certification option requires compliance with Sections R405 and
130 R404.4.
131
132 R401.2.3 Energy Rating Index option.
133 The Energy Rating Index (ERI) option requires compliance with Sections R406, R403.6 and
134 R404.4.
135
136 R401.2.4 Appendix RC. Residential Buildings and dwelling units covered by this chapter may
137 elect to comply with the requirements of IECC Appendix RC and R404 as amended.
138
139 R401.2.5 Additional energy efficiency. This section establishes additional requirements
140 applicable to all compliance approaches to achieve additional energy efficiency.
141 1. For buildings complying with Section R401.2.1, two of the additional efficiency
142 package options shall be installed according to Section R408.2.
143 2. For buildings electing to be all-electric buildings, both R408.2.2 and R408.2.3
144 shall apply for primary space heating and domestic hot water supply.
145
146 SECTION R402 BUILDING THERMAL ENVELOPE
147
148 Table R402.1.2 Modify Table R402.1.2 as follows:
149
150 TABLE R402.1.2 MAXIMUM ASSEMBLY U-FACTORSa AND FENESTRATION
151 REQUIREMENTS
CLIMA FENES SKYLI GLAZED CEILI WOOD MASS FLOO BASE CRAWL
TE TRATI GHT FENEST NG FRAM WAL R MENT SPACE
ZONE ON UFACT RATION UFACT E L U- UFACT WALL WALL
UFACTO OR SHGCd, e OR WALL FACT OR U- U-
Rf U- OR b FACTO FACTO
FACTO R R
R
5 and 0.30 0.55 NR 0.026 0.045 0.082 0.033 0.050 0.055
Marine
4
152
153 Table R402.1.3 Modify Table R402.1.3 as follows:
154
155 TABLE R402.1.3 INSULATION MINIMUM R-VALUES AND FENESTRATION
156 REQUIREMENTS BY COMPONENTa
157
CLIM FENE SKYL GLAZ CEILI WOO MASS FLOO BASE SLA CRAW
ATE STRA IGHT ED NG U- D WAL R MENT Bd L
c,g
ZONE TION UFACT FENE FACT FRAM L U- UFACT SPACE
OR WALL R-
UFACT OR STRA OR E FACT c,g
ORf R- VAL
TION WAL OR b WALL
SHGC L U- VALU UE
d, e E & R-
FACT
OR
DEP VALU
TH E
5 and 0.30 i 0.55 NR 49 20&5 13/17 30 15ci or 10ci, 15ci or
Marin ci or 19 or 4 ft 19 or
e4 13&1 13+5ci 13+5ci
0ci or
0&20
158
159
160 R402.1.5.1 Add Subsection R402.1.5.1 as follows:
161 R402.1.5.1 Approved software for Total UA alternative: The following software is approved
162 for demonstrating Total UA compliance: REScheck-Web for 2023 Massachusetts Stretch Energy
163 Code available at http://www.energycodes.gov/rescheck
164
165 R402.4.1.1 Amend Table R402.4.1.1 as follows:
166 TABLE R402.4.1.1 AIR BARRIER AND INSULATION INSTALLATION
COMPONENT AIR BARRIER CRITERIA INSULATION
INSTALLATION
CRITERIA
General requirements A continuous air barrier shall All insulation shall be
be installed in the building installed at Grade I quality in
envelope. accordance with
The exterior thermal ANSI/ICC/RESNET 301.
envelope contains a
continuous air barrier. Air-permeable insulation shall
Breaks or joints in the air not be used as a sealing
barrier shall be sealed. material.
167
168 SECTION R403 SYSTEMS
169
170 R403.3.5 Revise Section R403.3.5 as follows:
171
172 R403.3.5 Duct testing. Ducts shall be pressure tested in accordance with ANSI/RESNET/ICC
173 380 or ASTM E1554 to determine air leakage by one of the following methods:
174
175 1. Rough-in test: Total leakage shall be measured with a pressure differential of 0.1 inch w.g. (25
176 Pa) across the system, including the manufacturer’s air handler enclosure if installed at the
177 time of the test. Registers shall be taped or otherwise sealed during the test.
178 2. Postconstruction test: Total leakage shall be m