An Act to Address the Housing Crisis by Reducing Barriers to
Maine Legislature, Session 132, LD 1272
Committee: Housing and Economic Development
Sponsors: FECTEAU, PIERCE
Amends: 25 MRSA §2463-B, 30-A MRSA §4364-A, 30-A MRSA §4364-B, 30-A MRSA §4401, 30-A MRSA §4402, 33 MRSA §1601

Legislative Document
No. 1272
H.P. 847
House of Representatives, March 25, 2025
An Act to Address the Housing Crisis by Reducing Barriers to 
Building More Accessory Dwelling Units
Reference to the Committee on Housing and Economic Development suggested and 
ordered printed.
ROBERT B. HUNT
Clerk
Presented by Speaker FECTEAU of Biddeford.
Cosponsored by Senator PIERCE of Cumberland and
Representatives: JULIA of Waterville, KESSLER of South Portland, PUGH of Portland.
Be it enacted by the People of the State of Maine as follows:
Sec. 1.  25 MRSA §2463-B is enacted to read:
§2463-B.  Fire protection in accessory dwelling units
An accessory dwelling unit, as defined in Title 30-A, section 4301, subsection 1-C, 
located within an existing dwelling unit or attached to or sharing a wall with an existing 
dwelling unit is not required to have a fire sprinkler system as long as the wall between the 
accessory dwelling unit and the existing dwelling unit meets the fire resistance rating for 
town houses without fire sprinkler systems established in Department of Public Safety 
rules.  Accessory dwelling units that are not located within an existing dwelling unit or 
attached to or sharing a wall with an existing dwelling unit are not required to have a fire 
sprinkler system.  For purposes of this section, "dwelling unit" includes, but is not limited 
to, a structure with up to 3 separate dwelling units, including accessory dwelling units, and 
"fire sprinkler system" has the same meaning as in Title 32, section 1371, subsection 5.
This section does not require an existing dwelling unit to have fire sprinkler systems if 
the total number of dwelling units on the lot is 5 or less.
Sec. 2.  30-A MRSA §4364-A, sub-§1, as amended by PL 2023, c. 192, §6, is 
further amended by amending the first blocked paragraph to read:
A municipality shall allow on a lot with one existing dwelling unit the addition of up to 2 
dwelling units: one additional dwelling unit within or attached to an existing structure or 
one additional detached dwelling unit, or one of each.
Sec. 3.  30-A MRSA §4364-A, sub-§1-C is enacted to read:
1-C.  Sale or transfer allowed.  A municipality may not restrict or otherwise limit an 
owner's ability to sell or transfer separately a dwelling unit located on that owner's lot.
Sec. 4.  30-A MRSA §4364-A, sub-§2, as amended by PL 2023, c. 192, §8, is 
repealed and the following enacted in its place:
2.  Zoning requirements.  With respect to dwelling units allowed under this section, 
a municipal zoning ordinance must allow additional accessory dwelling units on a lot that 
contains fewer than 4 dwelling units that are single-family, duplex or triplex dwelling units 
or accessory dwelling units, or some combination of those, up to a total of 4 dwelling units 
per lot.
A.  If more than 4 dwelling units have been constructed on a lot as a result of the 
allowance under this section or section 4364‑B, the lot is not eligible for any additional 
increases in density except as allowed by the municipality.
B.  A municipal zoning ordinance may establish a prohibition or an allowance for lots 
where a dwelling unit in existence after the implementation date of this Act is torn 
down and an empty lot results.
Sec. 5.  30-A MRSA §4364-B, sub-§1, as amended by PL 2023, c. 192, §12, 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 in any area in which residential uses are permitted, including as a conditional use, in 
accordance with this section.
Sec. 6.  30-A MRSA §4364-B, sub-§3, ¶A, as amended by PL 2023, c. 192, §15, 
is repealed and the following enacted in its place:
A.  If a lot contains fewer than 4 units that are single-family, duplex or triplex dwelling 
units or accessory dwelling units, or some combination of those, additional accessory 
dwelling units must be allowed but only up to a total of 4 dwelling units per lot; and
Sec. 7.  30-A MRSA §4364-B, sub-§3, ¶B, as amended by PL 2023, c. 192, §15, 
is repealed.
Sec. 8.  30-A MRSA §4364-B, sub-§3, ¶C, as enacted by PL 2023, c. 192, §15, is 
amended to read:
C.  An accessory dwelling unit is must be allowed on a lot that does not conform to the 
municipal zoning ordinance if the accessory dwelling unit does not further increase the 
nonconformity.
Sec. 9.  30-A MRSA §4364-B, sub-§4, ¶A, as enacted by PL 2021, c. 672, §6, is 
amended to read:
A.  A municipality shall exempt an the first accessory dwelling unit on a lot from any 
density requirements or calculations related to the area in which the accessory dwelling 
unit is constructed.  Subsequent accessory dwelling units on that same lot are subject 
to density requirements or calculations related to the area in which the accessory 
dwelling unit is constructed.
Sec. 10.  30-A MRSA §4364-B, sub-§4, ¶E is enacted to read:
E.  An accessory dwelling unit located within an existing dwelling unit or attached to 
or sharing a wall with an existing dwelling unit is not required to have a fire sprinkler 
system as long as walls of the accessory dwelling unit separating the units meet the fire 
resistance rating for town houses without fire sprinkler systems established in 
Department of Public Safety rules.  Accessory dwelling units that are not located within 
an existing dwelling unit or attached to or sharing a wall with an existing dwelling unit 
are not required to have a fire sprinkler system.  For purposes of this subsection, "fire 
sprinkler system" has the same meaning as in Title 32, section 1371, subsection 5.
Sec. 11.  30-A MRSA §4364-B, sub-§4, ¶F is enacted to read:
F.  A municipality shall allow the construction or occupancy of an accessory dwelling 
unit on a lot even if the owner of the lot where the accessory dwelling unit is located 
does not reside in a dwelling unit on that lot.
Sec. 12.  30-A MRSA §4364-B, sub-§4, ¶G is enacted to read:
G.  A municipality may not restrict or otherwise limit an owner's ability to separately 
sell or transfer an accessory dwelling unit located on the owner's lot.
Sec. 13.  30-A MRSA §4401, sub-§4, as amended by PL 2023, c. 79, §1, is further 
amended to read:
4.  Subdivision.  "Subdivision" means the division of a tract or parcel of land into 3 5 
or more lots within any 5-year period that begins on or after September 23, 1971 December 
31, 2025.  This definition applies whether the division is accomplished by sale, lease, 
development, buildings or otherwise.  The term "subdivision" also includes the division of 
a new structure or structures on a tract or parcel of land into 3 5 or more dwelling units 
within a 5-year period, the construction or placement of 3 5 or more dwelling units on a 
single tract or parcel of land and the division of an existing structure or structures 
previously used for commercial or industrial use into 3 5 or more dwelling units within a 
5-year period.
A.  In determining whether a tract or parcel of land is divided into 3 5 or more lots, the 
first dividing of the tract or parcel is considered to create the first 2 lots and the next 
dividing of either of these first 2 lots, by whomever accomplished, is considered to 
create a 3rd lot that creates the 5th lot, by whomever accomplished, is considered to 
create a subdivision, unless:
(1)  Both All dividings are accomplished by a subdivider who has retained one of 
the lots for the subdivider's own use as a single-family residence that has been the 
subdivider's principal residence for a period of at least 5 years immediately 
preceding the 2nd division; or
(2)  The division of the tract or parcel is otherwise exempt under this subchapter.
B.  The dividing of a tract or parcel of land and the lot or lots so made, which dividing 
or lots when made are not subject to this subchapter, do not become subject to this 
subchapter by the subsequent dividing of that tract or parcel of land or any portion of 
that tract or parcel.  The municipal reviewing authority shall consider the existence of 
the previously created lot or lots in reviewing a proposed subdivision created by a 
subsequent dividing.
C.  A lot of 40 or more acres must be counted as a lot, except:
(2)  When a municipality has, by ordinance, or the municipal reviewing authority 
has, by regulation, elected not to count lots of 40 or more acres as lots for the 
purposes of this subchapter when the parcel of land being divided is located 
entirely outside any shoreland area as defined in Title 38, section 435 or a 
municipality's shoreland zoning ordinance.
D-1.  A division accomplished by devise does not create a lot or lots for the purposes 
of this definition, unless the intent of the transferor is to avoid the objectives of this 
subchapter.
D-2.  A division accomplished by condemnation does not create a lot or lots for the 
purposes of this definition, unless the intent of the transferor is to avoid the objectives 
of this subchapter.
D-3.  A division accomplished by order of court does not create a lot or lots for the 
purposes of this definition, unless the intent of the transferor is to avoid the objectives 
of this subchapter.
D-4.  A division accomplished by gift to a person related to the donor of an interest in 
property held by the donor for a continuous period of 5 years prior to the division by 
gift does not create a lot or lots for the purposes of this definition, unless the intent of 
the transferor is to avoid the objectives of this subchapter.  If the real estate exempt 
under this paragraph is transferred within 5 years to another person not related to the 
donor of the exempt real estate as provided in this paragraph, then the previously 
exempt division creates a lot or lots for the purposes of this subsection.  "Person related 
to the donor" means a spouse, parent, grandparent, brother, sister, child or grandchild 
related by blood, marriage or adoption.  A gift under this paragraph can not be given 
for consideration that is more than 1/2 the assessed value of the real estate.
D-5.  A division accomplished by a gift to a municipality if that municipality accepts 
the gift does not create a lot or lots for the purposes of this definition, unless the intent 
of the transferor is to avoid the objectives of this subchapter.
D-6.  A division accomplished by the transfer of any interest in land to the owners of 
land abutting that land does not create a lot or lots for the purposes of this definition, 
unless the intent of the transferor is to avoid the objectives of this subchapter.  If the 
real estate exempt under this paragraph is transferred within 5 years to another person 
without all of the merged land, then the previously exempt division creates a lot or lots 
for the purposes of this subsection.
E.  The division of a tract or parcel of land into 3 5 or more lots and upon each of which 
lots permanent dwelling structures legally existed before September 23, 1971 
December 31, 2025 is not a subdivision.
F.  In determining the number of dwelling units in a structure, the provisions of this 
subsection regarding the determination of the number of lots apply, including 
exemptions from the definition of a subdivision of land.
H-2.  This subchapter may not be construed to prevent a municipality from enacting an 
ordinance under its home rule authority that otherwise regulates land use activities.
A municipality may not enact an ordinance that expands the definition of "subdivision" 
except as provided in this subchapter.  A municipality that has a definition of 
"subdivision" that conflicts with the requirements of this subsection at the time this 
paragraph takes effect shall comply with this subsection no later than January 1, 2021 
June 30, 2026.  Such a municipality must file its conflicting definition at the county 
registry of deeds by June 30, 2020 December 31, 2025 for the definition to remain valid 
for the grace period ending January 1, 2021 June 30, 2026.  A filing required under this 
paragraph must be collected and indexed in a separate book in the registry of deeds for 
the county in which the municipality is located.
I.  The grant of a bona fide security interest in an entire lot that has been exempted from 
the definition of subdivision under paragraphs D‑1 to D‑6, or subsequent transfer of 
that entire lot by the original holder of the security interest or that person's successor 
in interest, does not create a lot for the purposes of this definition, unless the intent of 
the transferor is to avoid the objectives of this subchapter.
J.  Unless the intent of a transferor is to avoid the objectives of this subchapter, the 
division of a tract or parcel of land accomplished by the transfer of any interest in the 
land to a holder does not create a lot or lots for purposes of this definition if:
(1)  The transferred interest, as expressed by conservation easement, binding 
agreement, declaration of trust or otherwise, is to be permanently held for one or 
more of the following conservation purposes:
(a)  Retaining or protecting the natural, scenic or open space values of the land;
(b)  Ensuring the availability of the land for agricultural, forest, recreational or 
open space use;
(c)  Protecting natural resources; or
(d)  Maintaining or enhancing air quality or water quality; and
(2)  The transferred interest is not subsequently further divided or transferred 
except to another holder.
As used in this paragraph, "holder" has the same meaning as in Title 33, section 476, 
subsection 2.
Sec. 14.  30-A MRSA §4402, sub-§6, as amended by PL 2019, c. 174, §2, is further 
amended to read:
6.  Division of new or existing structures.  Beginning July 1, 2018 January 1, 2026, 
a division of a new or existing structure into 3 5 or more dwelling units whether the division 
is accomplished by sale, lease, development or otherwise in a municipality where the 
project is subject to municipal site plan review.
A.  For the purposes of this subsection, "municipal site plan review" means review 
under a municipal ordinance that sets forth a process for determining whether a 
development meets certain specified criteria, which must include criteria regarding 
stormwater management, sewage disposal, water supply and vehicular access and 
which may include criteria regarding other environmental effects, layout, scale, 
appearance and safety.
B.  The municipal reviewing authority in each municipality shall determine whether a 
municipal site plan review ordinance adopted by the municipality meets the 
requirements of paragraph A.
Sec. 15.  33 MRSA §1601-103, sub-§(7), as amended by PL 1983, c. 190, is further 
amended to read:
(7)  "Condominium" means real estate, portions of which are designated for separate 
ownership and the remainder of which is designated for common ownership solely by the 
owners of those portions under a declaration, or an amendment to a declaration, duly 
recorded pursuant to this Act.  Real estate is not a condominium unless the undivided 
interests in the common elements are vested in the unit owners. Any real estate 
development consisting exclusively of clustered, detached, single family single-family 
residences is not a condominium, unless so designated in the declaration.  More than one 
dwelling unit, including, but not limited to, an accessory dwelling unit, located on a single 
lot, but not all owned by the same person, is not a condominium, unless so designated in 
the declaration;
Sec. 16.  Effective dates. That section of this Act that amends the Maine Revised 
Statutes, Title 30-A, section 4401, subsection 4 takes effect December 31, 2025.  That 
section of this Act that amends Title 30-A, section 4402, subsection 6 takes effect January 
1, 2026.
SUMMARY
This bill allows up to 4 either single-family, duplex, triplex or accessory dwelling units 
on a single lot.  The bill exempts only the first accessory dwelling unit on a lot from 
municipal housing density requirements.  It prohibits a municipality from adopting an 
ordinance or other restriction that requires the owner of the lot to reside in one of the units 
on the lot.  It prohibits a municipality from adopting an ordinance or other restriction that 
requires a fire sprinkler system to be installed in certain accessory dwelling units.  It amends 
the definition of "subdivision" from a division of a tract or parcel of land into 3 or more 
lots to a division of a tract or parcel of land into 5 or more lots.   It clarifies that an accessory 
dwelling unit that otherwise complies with applicable state and local zoning requirements 
must be allowed on a nonconforming lot as long as the accessory dwelling unit does not 
further increase the nonconformity.