Code of Massachusetts Regulations
225 CMR - DEPARTMENT OF ENERGY RESOURCES
Title 225 CMR 22.00 - Massachusetts Stretch Code and Specialized Code 213 For Low-rise Residential
Chapter 4 - [RE] RESIDENTIAL ENERGY EFFICIENCY
Section R401 - GENERAL

Universal Citation: 225 CMR 22.00 MA Code of Regs R 401

Current through Register 1531, September 27, 2024

R401 Replace Section R401.1 and R401.2 as follows:

R401.1 Scope. This chapter applies to residential buildings. Municipalities which have adopted the Stretch Energy Code shall use the energy efficiency requirements of this chapter, or Chapter 51 where applicable for existing buildings. Municipalities which have adopted the Municipal Opt-in Specialized Stretch energy code shall comply with R401.2.4 including both the requirements of Appendix RC and this chapter.

R401.2 Application. Residential buildings shall comply with Section R401.2.5 and either Sections R401.2.2, R401.2.3 or R401.2.4. R-use buildings without individually separate dwelling units (such as single-room occupancy buildings) may comply with Section R401.2.1. The option selected for compliance shall be identified in the certificate required by Section R401.3.

Exception: Additions under 1,000 sf, level 1 and level 2 alterations, and repairs to existing buildings complying with Chapter 5 [RE].

R401.2.1 Prescriptive Compliance Option. The Prescriptive Compliance Option requires compliance with Sections R401 through R404 and R408.

R401.2.2 Passivehouse Building Certification Option. The Passivehouse Building Certification Option requires compliance with Section R405 and R404.4.

R401.2.3 Energy Rating Index Option. The Energy Rating Index (ERI) Option requires compliance with Section R406, R403.6 and R404.4.

R401.2.4 Appendix RC. Residential Buildings and dwelling units covered by this chapter may elect to comply with the requirements of IECC Appendix RC and R404 as amended.

R401.2.5 Additional Energy Efficiency. This section establishes additional requirements applicable to all compliance approaches to achieve additional energy efficiency.
1. For buildings complying with Section R401.2.1, two of the additional efficiency package options shall be installed according to Section R408.2.

2. For buildings electing to be all-electric buildings, both R408.2.2 and R408.2.3 shall apply for primary space heating and domestic hot water supply.

R402.1.5.1 Add Subsection R402.1.5.1 as follows:

R402.1.5.1 Approved Software for Total UA Alternative: The following software is approved for demonstrating Total UA compliance:

REScheck-Web for IECC2021 Massachusetts stretch code available at

http://www.energycodes.gov/rescheck

R402.4.1.1 Modify Table R402.4.1.1 to amend the Insulation Installation Criteria as follows:

TABLE R402.4.1.1 AIR BARRIER AND INSULATION INSTALLATION

COMPONENT

AIR BARRIER CRITERIA

INSULATION INSTALLATION CRITERIA

General requirements

A continuous air barrier shall be installed in the building envelope.

Breaks or joints in the air barrier shall be sealed.

All insulation shall be installed at Grade I quality in accordance with ICC/RESNET 301.

Air-permeable insulation shall not be used as a sealing material.

403.3.5 Insert the following to the end of Subsection R403.3.5:

Postconstruction or rough-in testing and verification shall be done by a HERS Rater, HERS Rating Field Inspector, or an applicable BPI Certified Professional. A written report of the results of the test shall be signed by the party conducting the test and provided to the ode official

R403.6 Replace Section R403.6 as follows:

R403.6 Mechanical Ventilation. Outdoor air intakes and exhausts shall have automatic or gravity dampers that close when the ventilation system is not operating.

Each dwelling unit of a residential building shall be provided with continuously operating mechanical balanced ventilation system that has been site verified to meet a minimum airflow per either:

1. RESNET HERS Index in accordance with RESNET/ICC Standard 301, or

2. ASHRAE Standard 62.2-2019 or 62.2-2022, or

3. the following formula for one- and two-family dwellings and townhouses of three or less stories above grade plane:

Q = .03 x CFA + 7.5 x (Nbr +1) - 0.052 x Q50 x S x WSF

Where: CFA is the conditioned floor area in sq. ft.

Nbr is the number of bedrooms

Q50 is the verified blower door air leakage rate in cfm measured at 50 Pascals

S is the building height factor determined by this table:

Stories above Grade Plane

1

2

3

S

1.00

1.32

1.55

WSF is the shielded weather factor as determined by this table:

County

WSF

Barnstable

0.60

Berkshire

0.52

Bristol

0.54

Dukes

0.59

Essex

0.58

Franklin

0.52

Hampden

0.49

Hampshire

0.59

Middlesex

0.55

Nantucket

0.61

Norfolk

0.52

Plymouth

0.53

Suffolk

0.66

Worcester

0.59

R403.6.1 Replace Subsection R403.6.1 and Subsections R403.6.1.1 and R403.6.1.2 as follows:

R403.6.1 Heat or Energy Recovery Ventilation. Heat or energy recovery balanced ventilation systems shall be provided for dwelling units as specified in either Section R403.6.1.1 or R403.6.1.2, as applicable.
R403.6.1.1 Large Systems. Systems with a rated airflow exceeding 300 cfm shall have an enthalpy recovery ratio of not less than 50% at cooling design condition and not less than 60% at heating design condition, determined in accordance with AHRI 1060 at an airflow not less than the design airflow.

R403.6.1.2 Other Systems. Systems with a rated airflow of 300 cfm or less shall have a sensible recovery efficiency (SRE) of not less than 65% at 32°F (0°C) at an airflow not less than the design airflow. SRE shall be determined in accordance with CAN/CSA-C439 and shall be listed. Linear interpolation of listed values for SRE shall be permitted.

R403.6.3 Replace Subsection R403.6.3 as follows:

R403.6.3 Testing and Verification. Installed performance of the mechanical ventilation system shall be tested and verified by a HERS Rater, HERS Rating Field Inspector, or an applicable BPI Certified Professional, and measured using a flow hood, flow grid, Residential IAQ Fault Indicator Display certified to the California Energy Commission, or other airflow measuring device in accordance with either RESNET Standard 380 or ACCA Standard 5.

R403.6.4 - R403.6.7 Add Subsections R403.6.4 - R403.6.7 as follows:

R403.6.4 Air-moving equipment, selection and installation. As referenced in ASHRAE Standard 62.2, Section 7.1, ventilation devices and equipment shall be tested and certified in accordance with HVI 920 (Home Ventilating Institute), or equivalent, and the certification label shall be found on the product. Installation of systems or equipment shall be carried out in accordance with manufacturers' design requirements and installation instructions. Where multiple duct sizes and/or exterior hoods are standard options, the minimum size shall not be used.

R403.6.5 Sound Rating. Sound ratings for fans used for whole building ventilation shall be rated at a maximum of 1.0 sone.

Exception: HVAC air handlers and remote-mounted fans need not meet sound requirements. There must be at least four feet of ductwork between the remote-mounted fan and intake grille.

R403.6.6 Documentation. The owner and the occupant of the dwelling unit shall be provided with information on the ventilation design and systems installed, as well as instructions on the proper operation and maintenance of the ventilation systems. Ventilation controls shall be labeled with regard to their function, unless the function is obvious or unless the function is communicated through a digital user interface provided with the control.

R403.6.7 Air Inlets and Exhausts. All ventilation air inlets shall be located a minimum of ten feet from vent openings for plumbing drainage systems, appliance vent outlets, exhaust hood outlets, vehicle exhaust, or other known contamination sources; and shall not be obstructed by snow, plantings, or any other material. Outdoor forced air inlets shall be covered with rodent screens having mesh openings not greater than 1/2 inch. A whole house mechanical ventilation system shall not extract air from an unconditioned basement unless approved by a registered design professional. Where wall inlet or exhaust vents are less than seven feet above finished grade in the area of the venting including, but not limited to, decks and porches, a metal or plastic identification plate shall be permanently mounted to the exterior of the building at a minimum height of eight feet above grade directly in line with the vent terminal. The sign shall read, in print size no less than 1/2 inch in size, "MECH. VENT DIRECTLY BELOW. KEEP CLEAR OF ALL OBSTRUCTIONS".

Exceptions:

1. Ventilation air inlets in the wall >= three feet from dryer exhausts and contamination sources exiting through the roof.

2. No minimum separation distance shall be required between local exhaust outlets in kitchens/bathrooms and windows.

3. Vent terminations that meet the requirements of the National Fuel Gas Code (NFPA 54/ANSI Z223.1) or equivalent.

R404.4 Add Section R404.4 and Table R404.4 as follows:

R404.4 Wiring for Electric Vehicle Ready Parking Spaces ("EV Ready Spaces"). EV Ready Spaces shall be provided in accordance with Table R404.4. The dedicated branch circuit shall be identified as "EV READY" in the service panel or subpanel directory, and the termination location shall be marked as "EV READY". The circuit shall terminate in a NEMA receptacle or a Society of Automotive Engineers (SAE) Standard SAE J1772 electrical connector for EV SE servicing Electric Vehicles, located within 6 feet (1828 mm) of each EV ready space. Conductors and outlets for EVSE shall be sized and installed in accordance with the MA electrical code.

TABLE R404.4 EV READY SPACE REQUIREMENTS

Type of Building

Number of Parking Spaces

1 & 2 family dwellings and town homes

At least one 50-amp branch circuit per dwelling unit to provide for AC Level II charging.

All other R-use buildings

At least 20% of spaces served with a 40-amp, 208/240-volt circuit with a minimum capacity of 9.6 kVA.

Exceptions:

1. In no case shall the number of required EV Ready Spaces be greater than the number of parking spaces installed.

2. This requirement will be considered met if all spaces which are not EV Ready are separated from the premises by a public right-of-way.

3. R-2 multi-family properties may elect to comply with Commercial EV ready requirements in C405.13

4. One or more SAE Level II spaces may be substituted with multiple SAE Level I spaces provided with wiring for a minimum 20amp, 120 volt EVSE, with a ratio of at least 3 Level I spaces for each Level II space required.

R405. Replace Section R405 in its entirety as follows:

Section R405 Passivehouse Building Certification Option.

R405.1 Compliance. Projects may document compliance with either Phius certification in accordance with R405.2 or PHI certification in accordance with R405.3.

Projects pre-certified as meeting the Phius CORE 2021 or Phius ZERO 2021 Passive Building Standard - North America, or newer, demonstrated using approved software by Phius, where Phius design-certification is demonstrated by Phius and a Certified Passive House Consultant (CPHC); or, Projects pre-certified as meeting the Certified Passive House standard using the current software and program criteria by the Passive House Institute (PHI), where PHI certification is demonstrated by a Certified Passive House Designer and a Certified Passive House Certifier.

R405.2 Phius Documentation. When using WUFI Passive or other Phius approved software:
1. Prior to the issuance of a building permit, the following items must be provided to the Building Official:
a. A Phius 2021 (or newer) Verification Report which demonstrates project compliance with Phius 2021 (or newer) performance requirements.

b. A statement from the CPHC that the verification report results accurately reflect the plans submitted.

c. Evidence of project registration from Phius.

OR

a. A Design Certification Letter from Phius.

2. Prior to the issuance of a certificate of occupancy, the following items must be provided to the building official:
a. Design Certification Letter from Phius.

b. An updated Verification Report by the CPHC which reflects "as-built" conditions and test results that demonstrate project compliance with Phius (blower door and ventilation results).

c. A statement from the CPHC that the envelope meets the Phius hygrothermal requirements found in Appendix B of the Phius 2021 Certification guidebook

d. A statement from the Phius Certified Verifier or Rater that the project test results and other Phius verification requirements are met.

e. A copy of the Phius workbook listing all testing results and as-built conditions.

OR

a. A Project Certificate demonstrating final certification awarded by Phius.

AND

f. A statement from the Phius Verifier or Rater of compliance with R404.4: EV ready, and Appendix RB: Solar Ready Provisions.

R405.3 Passive House International (PHI) Documentation.
1. If using PHI Passive House software, prior to the issuance of a building permit, the following items must be provided to the Building Official:
a. A PHPP compliance report which demonstrates project compliance with current PHI performance requirements;

b. A statement from the Certified Passive House Consultant/Designer (CPHC/D) that the PHPP results and compliance report accurately reflect the plans submitted;

c. Evidence of project registration from a Certified Passive House Certifier.

OR

a. A Design Certification Letter from a Certified Passive House Certifier.

2. Prior to the issuance of a certificate of occupancy, the following item(s) must be provided to the building official:
a. A Design Certification Letter from a Certified Passive House Certifier.

b. An updated PHPP compliance report which reflects "as-built" conditions and test results (blower door and ventilation results) that demonstrate project compliance with PHI performance requirements;

c. A statement from the CPHD that the project test results meet the model performance requirements, all the mandatory limits and any other mandatory requirements.

d. A copy of the Passive House Verifier's or Rater's test results;

OR

a. A Final Certification Letter from a Certified Passive House Certifier

AND

e. A statement from the Passive House Verifier or Rater of compliance with R404.4: EV ready, and Appendix RB: Solar Ready Provisions.

R406.2 Revise TABLE R406.2 as follows:

TABLE R406.2 REQUIREMENTS FOR ENERGY RATING INDEX

SECTIONa

TITLE

R403.6.1

Heat or Energy Recoveryl Ventilation

Electrical Power and Lighting Systems

R404.1

Lighting equipment

R404.2

Interior lighting controls

R404.4

Wiring for Electric Vehicle Charging Spaces
a. Reference to a code section includes all of the relevant subsections except as indicated in the table.

R406.3 Reserve this section:

R406.3 Building Thermal Envelope. Reserved.

R406.4 Replace Section R406.4 with the following:

R406.4 Energy Rating Index. The Energy Rating Index (ERI) shall be the RESNET certified HERS index determined in accordance with RESNET/ICC 301. Energy used to recharge or refuel a vehicle used for transportation on roads that are not on the building site shall not be included in the ERI reference design or the rated design.

R406.5 Replace Section R406.5 and Table R406.5 with the following:

R406.5 ERI-based Compliance. Compliance based on an ERI analysis requires that the rated proposed design and confirmed built dwelling be shown to have an HERS index rating less than or equal to the appropriate value indicated in Table R406.5 when compared to the HERS index reference design for each dwelling unit prior to credit for onsite renewable electric generation.

TABLE R406.5 MAXIMUM ENERGY RATING INDEX

Clean Energy Application

Maximum HERS Index scorea, b

New construction until June 30, 2024

New construction permits after July 1, 2024

Major alterations, additions, or Change of usec

Mixed-Fuel Building

52

42

52

Solar Electric Generation

55

42

55

All-Electric Building

55

45

55

Solar Electric & All-Electric Building

58

45

58

a Maximum HERS rating prior to onsite renewable electric generation in accordance with Section R406.5

b The building shall meet the mandatory requirements of Section R406.2, and the building thermal envelope shall be greater than or equal to the levels of efficiency and SHGC in Table R402.1.2 or Table R402.1.4 of the 2015 International Energy Conservation Code.

c Alterations, Additions or Change of use covered by Section R502.1.1 or R503.1.5 are subject to this maximum HERS rating.

R406.5.1 Add Subsection R406.5.1, as follows:

R406.5.1 Trade-off for Clean Energy Systems. New construction following Section R406 or existing buildings and additions following IECC Chapter 5[RE] may use clean energy trade-offs to increase the maximum allowable HERS rating for each unit separately served by any combination of the following:
1. Solar Electric Generation: Solar photovoltaic array rated at 4kW or higher shall offset three HERS points for Level 3 alterations, change of use to Residential R-use categories or for fully attached additions.

2. All-Electric Buildings shall offset three HERS points for each dwelling unit in new construction, Level 3 alterations, change of use to Residential R-use categories and fully attached additions.

R406.6 Revise Section R406.6 by replacing the reference to Section R406.6 in the first sentence with reference to Section R406.5.

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