An Act to Update the Laws Regarding Housing Developments and Accessory Dwelling Units

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STATE OF MAINE
_____
IN THE YEAR OF OUR LORD
TWO THOUSAND TWENTY-SIX
_____
H.P. 1461 - L.D. 2173
An Act to Update the Laws Regarding Housing Developments and Accessory
Dwelling Units
Be it enacted by the People of the State of Maine as follows:
Sec. 1. 25 MRSA §2463-B, as enacted by PL 2025, c. 385, §1, is amended to read:
§2463-B. Fire protection in accessory dwelling units
Fire suppression sprinklers are not required for an accessory dwelling unit unless the
accessory dwelling unit is within or attached to a structure of that contains, or will contain
upon completion of construction, more than 2 dwelling units, including accessory dwelling
units. As used in this section, "accessory dwelling unit" has the same meaning as in Title
30‑A, section 4301, subsection 1‑C. This section may not be construed to exempt an
accessory dwelling unit from fire protection requirements when the unit is located within
or attached to a mixed-use or nonresidential building or when sprinkler protection is
otherwise required based on occupancy classification, building use or hazard level under
the National Fire Protection Association codes adopted pursuant to section 2452.
Sec. 2. 30-A MRSA §4351-A is enacted to read:
§4351-A. Definition
As used in this subchapter, unless the context otherwise indicates, "public sewer
system" means a sewer system managed, owned or operated by a municipality or quasi-
municipal entity that is a municipal sewer department, a sewer district as defined in Title
38, section 1032, subsection 3, a standard district as defined in Title 38, section 1032,
subsection 4 or a sanitary district formed under Title 38, chapter 11.
Sec. 3. 30-A MRSA §4360, as amended by PL 2025, c. 385, §3 and affected by
§23, is further amended to read:
§4360. Rate of growth ordinances
1. Ordinance review and update. A municipality that enacts a rate of growth
ordinance shall review and update the ordinance at least every 3 years to determine whether
the rate of growth ordinance is still necessary and how the rate of growth ordinance may
be adjusted to meet current conditions.
APPROVED
APRIL 16, 2026
BY GOVERNOR
CHAPTER
733
PUBLIC LAW
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1-A. Definition; common scheme of development. As used in this section, unless
the context otherwise indicates, "common scheme of development" means a plan or process
of development that:
A. Takes place on contiguous parcels or lots in the same immediate vicinity; and
B. Exhibits characteristics of a unified approach, method or effect, such as:
(1) Unified ownership, management or supervision;
(2) Sharing common equipment or labor; or
(3) Common financing.
2. Differential ordinances. A municipality may enact rate of growth ordinances that
set different limits on the number of building or development permits that are permitted in
designated rural different areas. A, except that a municipality may not enact or enforce rate
of growth ordinances that limit residential development in designated growth areas, as
defined in section 4301, subsection 6‑C, except as authorized by this chapter subsection 3.
3. Ordinance requirements; growth areas. A municipality may adopt a rate of
growth ordinance that applies to a designated growth area only if:
A. The ordinance is consistent with section 4314, subsection 3;
B. The ordinance sets the number of building or development permits for new
residential dwellings, not including permits for affordable housing, at 105% or more
of the mean number of total permits issued for new residential dwellings within the
municipality during the 10 years immediately prior to the year in which the number is
calculated. The mean is determined by adding together the total number of permits
issued, excluding permits issued for affordable housing, for new residential dwellings
for each year in the prior 10 years and then dividing by 10;
C. In addition to the permits established pursuant to paragraph B, the ordinance sets
the number of building or development permits for affordable housing at no less than
10% of the number of permits set in the ordinance pursuant to paragraph B; and
C-1. The ordinance does not restrict the number of building permits or require a
development permit for affordable housing as defined in section 5246, subsection 1;
D. The number of building or development permits for new residential dwellings
allowed under the ordinance is recalculated every 3 years.; and
E. Within the designated growth area, the ordinance does not limit the development
permits allowed per project or per common scheme of development to a number that
is less than 35% of the allocated permits for that area.
4. Ordinance requirements; other areas. A municipality may adopt a rate of growth
ordinance applicable to all other areas without limitation by this section.
Sec. 4. 30-A MRSA §4364, first ¶, as amended by PL 2023, c. 192, §1, is further
amended to read:
For an affordable housing development approved on or after the implementation date,
a municipality with density requirements shall apply density requirements and a
municipality with height restriction requirements shall apply height allowance
requirements in accordance with this section.
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Sec. 5. 30-A MRSA §4364, sub-§2, as amended by PL 2025, c. 385, §4 and
affected by §23 and amended by c. 388, Pt. D, §36, is repealed and the following enacted
in its place:
2. Density requirements. A municipality shall allow an affordable housing
development where multifamily dwellings are allowed to have a dwelling unit density of
at least 2 1/2 times the base density that is otherwise allowed in that location and may not
require more than 2 off-street parking spaces for every 3 units. The development must be
in a designated growth area of a municipality as identified in a comprehensive plan adopted
pursuant to subchapter 2 or be served by a water system delivering water drawn from a
public water source as defined in Title 22, section 2641 and a public sewer system.
Sec. 6. 30-A MRSA §4364, sub-§2-A, as enacted by PL 2025, c. 385, §5 and
affected by §23, is amended to read:
2-A. Additional height allowance. Except as otherwise prohibited under Title 38,
chapter 3 and municipal shoreland zoning ordinances, a municipality shall allow, subject
to review by a municipal fire official or designee, an affordable housing development to
exceed any municipal height restriction by no less than one story or 14 feet but only up to
a total building height of 55 feet. To be eligible for the additional height allowance pursuant
to this subsection, an affordable housing development must be approved by the Office of
the State Fire Marshal or a municipality registered under Title 25, section 2448-A and must
be:
A. In a designated growth area of a municipality as identified in a comprehensive plan
adopted pursuant to subchapter 2; or
B. Served by a water system delivering water drawn from a public water source as
defined in Title 22, section 2641 and a public sewer system.
Sec. 7. 30-A MRSA §4364, sub-§5, ¶A, as enacted by PL 2021, c. 672, §4, is
amended to read:
A. If a housing unit is connected to a public, special district or other comparable sewer
system, proof of adequate service to support any additional flow created by the unit
and proof of payment for the connection to the sewer system;
Sec. 8. 30-A MRSA §4364, sub-§5, ¶C, as enacted by PL 2021, c. 672, §4, is
amended to read:
C. If a housing unit is connected to a public, special district or other centrally managed
water system served by a water system delivering water drawn from a public water
source as defined in Title 22, section 2641, proof of adequate service to support any
additional flow created by the unit, proof of payment for the connection and the volume
and supply of water required for the unit; and
Sec. 9. 30-A MRSA §4364, sub-§5, as amended by PL 2025, c. 385, §6 and
affected by §23, is further amended by repealing the first blocked paragraph.
Sec. 10. 30-A MRSA §4364, sub-§9, as enacted by PL 2023, c. 264, §1, is repealed
and the following enacted in its place:
9. Exceptions. This section does not apply to:
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A. A lot or portion of a lot that is within the watershed of a water source that is located
in the City of Lewiston or the City of Auburn and that is used to provide drinking water
by a water utility that has received a waiver from filtration pursuant to 40 Code of
Federal Regulations, Sections 141.70 to 141.76, as determined by the Department of
Health and Human Services; or
B. A lot or a portion of a lot that is within an area identified as a coastal barrier in Title
38, section 1904; an area of special flood hazard as defined in Title 38, section 436-A,
subsection 1-C; or an area within a coastal sand dune system as defined in Title 38,
section 480-B, subsection 1 as long as a municipality exempts the lot or portion of the
lot in a duly adopted ordinance.
Sec. 11. 30-A MRSA §4364-A, as amended by PL 2025, c. 385, §§7 to 12 and
affected by §23 and amended by c. 388, Pt. D, §37, is further amended by amending the
section headnote to read:
§4364-A. Residential areas,; generally; up to 4 dwelling units allowed
Sec. 12. 30-A MRSA §4364-A, sub-§1, as repealed and replaced by PL 2025, c.
385, §7 and affected by §23 and amended by c. 388, Pt. D, §37, is repealed and the
following enacted in its place:
1. Use allowed. Notwithstanding any provision of law to the contrary, except Title
12, chapter 423-A, for any area in which residential uses are allowed, including as a
conditional use, the following are permitted uses:
A. At least 3 dwelling units, attached or detached, inclusive of accessory dwelling
units, per lot; and
B. At least 4 dwelling units, attached or detached, inclusive of accessory dwelling
units, per lot if the lot is located in a designated growth area, as identified in a
comprehensive plan adopted pursuant to subchapter 2, or the lot is served by a water
system delivering water drawn from a public water source as defined in Title 22,
section 2641 and a public sewer system.
A municipality may allow more dwelling units than the minimum number required by this
subsection.
Sec. 13. 30-A MRSA §4364-A, sub-§1-B, as enacted by PL 2023, c. 264, §2 and
reallocated by RR 2023, c. 1, Pt. A, §26, is repealed and the following enacted in its place:
1-B. Exceptions. This section does not apply to:
A. A lot or portion of a lot that is within the watershed of a water source that is located
in the City of Lewiston or the City of Auburn and that is used to provide drinking water
by a water utility that has received a waiver from filtration pursuant to 40 Code of
Federal Regulations, Sections 141.70 to 141.76, as determined by the Department of
Health and Human Services; or
B. A lot or a portion of a lot that is within an area identified as a coastal barrier in Title
38, section 1904; an area of special flood hazard as defined in Title 38, section 436-A,
subsection 1-C; or an area within a coastal sand dune system as defined in Title 38,
section 480-B, subsection 1 as long as a municipality exempts the lot or portion of the
lot in a duly adopted ordinance.
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Sec. 14. 30-A MRSA §4364-A, sub-§2-A, as enacted by PL 2025, c. 385, §9 and
affected by §23, is repealed and the following enacted in its place:
2-A. Limitations on municipal ordinances related to lot size and density allowance
for private property rights protection. Notwithstanding any provision of law to the
contrary, except Title 12, chapter 423‑A, this subsection applies to any area in which
residential uses are allowed, including as a conditional use.
A. If a lot is located in a designated growth area and is served by a water system
delivering water drawn from a public water source as defined in Title 22, section 2641
and a public sewer system, a municipal ordinance may not require a minimum lot size
that exceeds 5,000 square feet and may not require more than 1,250 square feet of lot
area per dwelling unit for the first 4 dwelling units.
B. If a lot is located outside a designated growth area and in an area served by a water
system delivering water drawn from a public water source as defined in Title 22,
section 2641 and a public sewer system, a municipal ordinance may not require a
minimum lot size that exceeds 10,000 square feet and may not require more than
10,000 square feet of lot area for the first dwelling unit or 20,000 square feet of lot area
for the first 2 dwelling units within a single structure.
C. If a lot is located in a designated growth area without a public sewer system, a
municipal ordinance may not require a minimum lot size that exceeds 20,000 square
feet or a density requirement or calculation that is more restrictive than required by
Title 12, chapter 423‑A.
If 4 dwelling units have been constructed on a lot, the lot is not eligible for any additional
increases in density, including under section 4364, unless more units are allowed by the
municipality.
Sec. 15. 30-A MRSA §4364-A, sub-§5-A, as enacted by PL 2025, c. 385, §12 and
affected by §23, is amended to read:
5-A. Planning board approval not required. A For any area in which residential
uses are allowed, including as a conditional use, a municipality may not require planning
board approval for accessary dwelling units or solely because the project will establish 4
or fewer dwelling units within a single structure on a lot.
Sec. 16. 30-A MRSA §4364-B, sub-§1, as amended by PL 2025, c. 385, §13 and
affected by §23, is further amended to read:
1. Use permitted. Except as provided in Title 12, chapter 423‑A, a municipality shall
allow an accessory dwelling unit to be located on the same lot as a single-family dwelling
unit or multi-unit 2-unit or 3-unit residential structure in any area in which residential uses
are permitted, including as a conditional use, in accordance with this section.
Sec. 17. 30-A MRSA §4364-B, sub-§2, ¶B, as amended by PL 2025, c. 385, §14
and affected by §23, is further amended to read:
B. Attached to or sharing a wall with a single-family dwelling unit or multi-unit
residential structure; or
Sec. 18. 30-A MRSA §4364-B, sub-§3, ¶A, as amended by PL 2025, c. 385, §15
and affected by §23, is further amended to read:
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A. At least one accessory dwelling unit must be allowed on any lot where a single-
family dwelling unit is the principal structure is a single-family dwelling unit or 2-unit
or 3-unit residential structure; and
Sec. 19. 30-A MRSA §4364-B, sub-§8, as amended by PL 2025, c. 648, §4, is
further amended to read:
8. Municipal implementation. In adopting an ordinance under this section, a
municipality may:
A. Establish an application and permitting process for accessory dwelling units that
does not require planning board approval;
B. Impose fines for violations of building, zoning and utility requirements for
accessory dwelling units; and
C. Establish alternative criteria that are less restrictive than the requirements of
subsections 4, 5, 6 and 7 for the approval of an accessory dwelling unit only in
circumstances in which the municipality would be able to provide a variance under
section 4353, subsection 4, 4‑A, 4‑B, 4‑C or 4-D.; and
D. Exempt a lot or portion of a lot that is within an area identified as a coastal barrier
in Title 38, section 1904; an area of special flood hazard as defined in Title 38, section
436-A, subsection 1-C; or an area within a coastal sand dune system as defined in Title
38, section 480-B, subsection 1.
Sec. 20. 30-A MRSA §4364-D, sub-§1, ¶C is enacted to read:
C. "Small child care facility" has the same meaning as in Title 22, section 8301-A,
subsection 1-A, paragraph E.
Sec. 21. 30-A MRSA §4364-D, sub-§2, as enacted by PL 2025, c. 288, §2, is
amended to read:
2. Location of child care. A child care facility or a family child care provider is must
be a permitted use in a municipal area that is zoned for residential purposes,. A family child
care provider or small child care facility located in an area zoned for residential purposes
must be subject to the same zoning requirements for other residential property as a single-
family dwelling unit.
Sec. 22. 30-A MRSA §4364-E, as enacted by PL 2025, c. 364, §2 and reallocated
by RR 2025, c. 1, Pt. A, §42, is amended by enacting at the end a new paragraph to read:
This section does not apply to areas allowing industrial uses.
Sec. 23. PL 2025, c. 288, §3 is enacted to read:
Sec. 3. Application; retroactivity. That section of this Act that enacts the Maine
Revised Statutes, Title 30-A, section 4364-D applies to municipalities beginning July 1,
2027. This section applies retroactively to September 24, 2025.
Sec. 24. PL 2025, c. 374, §2 is enacted to read:
Sec. 2. Application; retroactivity. This Act applies to municipalities beginning
July 1, 2027. This section applies retroactively to September 24, 2025.
Sec. 25. PL 2025, c. 385, §23 is amended to read:
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Sec. 23. Application. Notwithstanding any provision of law to the contrary, except
for those sections of this Act that enact the Maine Revised Statutes, Title 25, section
2463-B, amend Title 30-A, section 4301, subsection 1-C and enact Title 30-A, section
4364-C, subsection 4, this Act applies to municipalities for which ordinances may be
enacted by the municipal officers without further action or approval by the voters of the
municipality beginning July 1, 2026 and applies to all other municipalities beginning July
1, 2027.
Sec. 26. General application date; changes to public laws retroactive.
Notwithstanding any provision of law to the contrary, except for those sections of this Act
that amend Public Law 2025, chapters 288, 374 and 385, this Act applies to municipalities
beginning July 1, 2027. Those sections of this Act that amend Public Law 2025, chapters
288, 374 and 385 apply retroactively to September 24, 2025.