1. 08 MAINE OFFICE OF COMMUNITY AFFAIRS
   1. 003 BUILDING CODES AND STANDARDS

      Chapter 6: MAINE UNIFORM BUILDING AND ENERGY CODE - RESIDENTIAL BUILDING CODE FOR ONE AND TWO-FAMILY DWELLINGS IN MAINE (formerly 16-642 C.M.R. Ch. 5)

SUMMARY: This chapter establishes the Residential Building Code for One and Two-Family Dwellings component of the Maine Uniform Building and Energy Code (“MUBEC”). The provisions of this chapter are based on a nationally recognized model building code published by the International Code Council, Inc., and is made part of the MUBEC through incorporation by reference.

1. SECTION 1. PURPOSE AND SCOPE

   All building construction within the State of Maine shall be governed by the MUBEC. The MUBEC is adopted by the Technical Building Codes and Standards Board pursuant to Title 10 M.R.S. Chapter 1103. The primary objective of the Board is to establish a uniform building code throughout the State of Maine.

   This chapter sets forth the standards for residential construction for one and two-family dwellings that are part of the MUBEC. It applies to the construction, alteration, movement, enlargement, replacement, repair, equipment, use and occupancy, location, removal and demolition of detached one- and two-family dwellings and townhouses not more than three stories above grade plane in height with a separate means of egress and their accessory structures.

   EFFECTIVE DATE: The effective date of this Chapter is 90 days after approval by the Commissioner of the Department of Public Safety.

   1. SECTION 2. AUTHORITY

   The authority for this Chapter is Title 10 M.R.S. §9722, which provides that the Maine Technical Building Codes and Standards Board shall promulgate rules which adopt, amend, and maintain the Maine Uniform Building and Energy Code.

   1. SECTION 3. DEFINITIONS
   2. 1. IRC. “IRC” means the 2021 International Residential Code, published by the International Code Council, Inc.
   3. 2. NFPA. “NFPA” means The National Fire Protection Association.
   4. 3. MUBEC. “MUBEC” means the Maine Uniform Building and Energy Code adopted pursuant to Title 10 M.R.S. §9271, et seq..
   5. 4. Technical Building Codes and Standards Board. “Technical Building Codes and Standards Board” means the board established pursuant to Title 5 M.R.S. §12004-G, subsection 5-A and Title 10 M.R.S. §9722.

      SECTION 4: INCORPORATION BY REFERENCE

   6. 1. The following Chapters of the 2021 International Residential Code, published by the International Code Council, Inc., are hereby adopted and incorporated by reference:
      1. A. Chapters 1 - 11
      2. B. Chapter 15
      3. C. Chapter 44
      4. D. Appendices AJ, AQ, AR, AS, AU, and AW
   7. 2. The following Chapters and appendices of the IRC are specifically excluded from adoption:
      1. A. Chapters 12 - 14
      2. B. Chapters 16 – 43
      3. C. Appendices AA - AI, AK - AP, AT, AV, and AX

      SECTION 5. REVISIONS TO THE IRC

   The following additions, insertions, deletions, and other changes are hereby made to the 2021 International Residential Code:

1. Generally all sections

1. Reference to “P2904” or “NFPA 13D” means; “A Sprinkler System in compliance with Fire Codes and Standards adopted pursuant to Title 25, sections 2452 and 2465”

2. Generally all sections

Delete “International Fire Code”; and

1. Insert “Fire codes and standards adopted pursuant to Title 25, M.R.S §§ 2452 and 2465 as applicable” in its place.

3. Generally all sections

1. Delete “International Fuel Gas Code”; and
   1. Insert “NFPA 54 National Fuel Gas Code; Fire codes and standards adopted pursuant to Title 25 M.R.S §§ 2452 and 2465; and the Maine Fuel Board Rules and codes and standards adopted pursuant to Title 32 Chapter 139” in its place.

4. Generally all sections

1. Delete “International Plumbing Code”; and
   1. Insert “State of Maine Plumbing Code adopted pursuant to Title 32, M.R.S § 3403-B as applicable” in its place.

5. Generally all sections

1. Delete “International Property Maintenance Code” without substitution.

6. Generally all sections

1. Delete “International Private Sewerage Disposal Code”; and
   1. Insert “State of Maine Subsurface Wastewater Disposal Rules adopted pursuant to Title 42, M.R.S § 42 (3, 3-A, 3-B) as applicable” in its place.

7. Section R101.1

1. Delete [NAME OF JURISDICTION]; and
   1. Insert “State of Maine” in its place.

8. Section R101.2

1. Delete entire Exception and Subcategories; and
   1. Insert “Exception: The following shall be permitted to be constructed in accordance with this code:
      1. 1. Live/Work unit provided the portion used exclusively for nonresidential use shall be limited to less than 10 percent of the area of the dwelling unit.
      2. 2. Detached one- and two-family dwellings or townhouses accommodating no more than 3 outsiders in rented rooms provided the rooms do not contain separate cooking facilities.
      3. 3. A “Day-Care Home” as defined by “Fire Codes and Standards adopted pursuant to Title 25, M.R.S §§ 2452 and 2465” in its place.

9. Section R103

1. Delete Section R103 “Department of Building Safety” in its entirety, without substitution.

10. Section R104.8

1. Delete all language in Section R104.8 Liability.; and
   1. Insert “Title 14 M.R.S. Chapter 741” in its place.

11. Section R105.1

1. Insert “where required by municipal ordinance.” at the end of the paragraph.

12. Section R105.2

1. Insert “or as further exempted by municipal ordinance.” at the end of the paragraph.
   1. Delete language in “Building” category item #3; and

      Insert “Retaining walls that are not over 4 feet (1219 mm) in height measured from finish grade to the top of the wall, unless supporting a surcharge.” in its place.

      Delete categories and associated subcategories “Electrical”, “Gas”, “Mechanical”, and “Plumbing” in their entirety.

13. Section R105.3

1. Delete “department of building safety” in the first paragraph; and
   1. Insert “municipality” in its place.

14. Section R105.3.1

1. Delete “within a reasonable time after filing”; and
   1. Insert “in accordance with Title 30A M.R.S. §4103” in its place.

15. Section R108

1. Delete Section R108 “Fees” in its entirety, without substitution.

16. Section R112

1. Delete Section R112 “Board of Appeals” in its entirety, without substitution.

17. Section R113

1. Delete Section R113 “Violations” in its entirety, without substitution.

18. Section R301.2

1. Insert new Section “R301.2.5 “Radon Control”: A Radon Control system constructed in compliance with ASTM E1465-08 Standard Practice for Radon Control Options for the Design and Construction of New Low-Rise Residential Buildings, shall be installed in new one- and two-family dwellings and townhouses.”
2. 19. Table R302.6

   Delete all reference to “½-inch gypsum board or equivalent”; and

   Insert “5/8-inch Type-X gypsum board or equivalent” in its place.

20. Section R310.2.1

1. Delete “Exception: The minimum net clear opening for grade-floor emergency escape and rescue openings shall be 5 square feet (0.465 m2).”

21. Section 310.4

1. Insert at end of sentence: “Area wells shall be maintained free and clear at all times.”

22. Section R313.1.1

1. Delete all language after heading in R313.1.1; and
   1. Insert “Automatic sprinkler systems for townhouses shall be designed and installed in compliance with Fire Codes and Standards adopted pursuant to Title 25, M.R.S §§ 2452 and 2465” in its place.

23. Section R313.2

1. Delete all language after heading in R313.2; and
   1. Insert “An automatic sprinkler system is not required in one- and two-family dwellings, including additions or alterations to existing buildings that are not already provided with a sprinkler system.” in its place.

24. Section R313.2.1

1. Delete all language after heading in R313.2.1; and
   1. Insert “Automatic sprinkler systems shall be designed and installed in compliance with Fire Codes and Standards adopted pursuant to Title 25, M.R.S §§ 2452 and 2465” in its place.

25. Section R502.1.1

1. Insert after section:
   1. “Exceptions:
      1. 1. Sawn lumber used in buildings and structures exempt from permit by R105.2
      2. 2. Sawn lumber used in free-standing non-habitable accessory structures with an area of 600 square feet (56 m2) or less, of light-frame construction, with an eave height of 10 feet (3048 mm) or less.”
2. 26. Section R602.1.1
   1. Insert after section:

      “Exceptions:

      1. 1. Sawn lumber used in buildings and structures exempt from permit by R105.2
      2. 2. Sawn lumber used in free-standing non-habitable accessory structures with an area of 600 square feet (56 m2) or less, of light-frame construction, with an eave height of 10 feet (3048 mm) or less.”

27. Section R802.1.1

1. Insert after section:
   1. “Exceptions:
      1. 1. Sawn lumber used in buildings and structures exempt from permit by R105.2
      2. 2. Sawn lumber used in free-standing non-habitable accessory structures with an area of 600 square feet (56 m2) or less, of light-frame construction, with an eave height of 10 feet (3048 mm) or less.”

28. Section M1505.1

1. Insert (at the end of the sentence) “, the International Mechanical Code as applicable, ASHRAE 62.2-2019, or other approved means of ventilation.”

29. Chapter 44

1. Insert (after “NFPA”) “Where the edition of a listed standard conflicts with the edition of a standard adopted by the Maine Office of State Fire Marshal, the version adopted by the Maine Office of State Fire Marshal is applicable to the extent referenced by this code.”

   STATUTORY AUTHORITY: Title 10 M.R.S. §9722

EFFECTIVE DATE:

October 11, 2010 – filing 2010

AMENDED:

January 23, 2018 – filing 2018-010

March 4, 2025 – filing 2025-046

APAO ACCESSIBILITY CHECK: July 31, 2025

TRANSFER OF AUTHORITY TO ADMINISTER AND ENFORCE RULE: The authority to administer and enforce this rule (formerly 16-642 C.M.R. Ch. 5) was transferred to the Maine Office of Community Affairs on September 24, 2025 pursuant to PL 2025, c. 388.