An Act To Remove Barriers to Accessory Dwelling Units and Allow Accessory Dwelling Units where Single-family Houses Are Allowed
Maine Legislature, Session 130, LD 1312
Committee: State and Local Government
Sponsors: GEIGER, MIRAMANT, BAILEY, DOUDERA, MORALES, OSHER
Amends: 30-A MRSA §3015

Legislative Document
No. 1312
H.P. 968
House of Representatives, March 30, 2021
An Act To Remove Barriers to Accessory Dwelling Units and Allow 
Accessory Dwelling Units where Single-family Houses Are Allowed
Reference to the Committee on State and Local Government suggested and ordered printed.
ROBERT B. HUNT
Clerk
Presented by Representative GEIGER of Rockland.
Cosponsored by Senator MIRAMANT of Knox and
Representatives: BAILEY of Gorham, DOUDERA of Camden, MORALES of South Portland, 
OSHER of Orono.
Be it enacted by the People of the State of Maine as follows:
Sec. 1.  30-A MRSA §3015 is enacted to read:
§3015.  Accessory dwelling units
1.  Use permitted.  A municipality shall allow one accessory dwelling unit, as defined 
in section 4301, subsection 1-C, to be located on the same lot as a single-family dwelling 
unit.
2.  Prohibited requirements.  A municipality may not: 
A.  Require additional setbacks for an accessory dwelling unit that is within an existing 
single-family dwelling unit;
B.  Require side and back setbacks greater than 5 feet for newly constructed accessory 
dwelling units;
C.  Except as provided in paragraph E, require new or additional off-street parking 
spaces;
D.  Except as provided in paragraph E, require the owner of the single-family dwelling 
unit to occupy either the single-family dwelling unit or the accessory dwelling unit;
E.  Prohibit use of the single-family dwelling unit or the accessory dwelling unit as a 
short-term rental or vacation rental, as defined in Title 22, section 2491, subsection 17, 
except that a municipality may require additional off-street parking and that the owner 
occupy the dwelling unit not used as a short-term rental or vacation rental;
F.  Prohibit inclusion of an accessory dwelling unit into a single-family dwelling unit 
that does not conform to existing land or building use ordinances as long as the 
inclusion does not increase the nonconformity and both units meet applicable fire 
safety and building codes; 
G.  Prohibit the conversion of a structure located on the lot of a single-family dwelling 
unit that does not conform to existing land or building use ordinances into an accessory 
dwelling unit as long as the conversion does not increase the nonconformity of the 
structure and the accessory dwelling unit created meets applicable fire safety and 
building codes; or
H.  Require separate sewer or water connections for an accessory dwelling unit.
3.  Design standards.  Design standards for accessory dwelling units established by a 
municipality must be clear and objective.
4.  Historical districts.  Notwithstanding contrary provisions in subsections 2 and 3, 
an accessory dwelling unit in a historical preservation district must comply with the design 
standards applicable in the historical district.
SUMMARY
This bill requires municipalities to allow one accessory dwelling unit to be included 
within or located on the same lot as a single-family dwelling unit.  It prevents municipalities 
from imposing any of the following for accessory dwelling units: setback requirements on 
accessory dwelling units incorporated within an existing single-family dwelling unit; 
setback requirements of more than 5 feet for accessory dwelling units not included within 
a single-family dwelling unit; off-street parking requirements; separate sewer or water 
systems; or owner occupancy of one of the units unless one of the units is being used for 
short-term or vacation rentals.  A municipality may not restrict use of one of the units on a 
lot as a short-term or vacation rental.  A municipality may not require correction of a 
nonconforming use when an accessory dwelling unit is incorporated into an existing single-
family dwelling unit or of an existing structure converted into an accessory dwelling unit, 
but a municipality may require compliance with applicable building and fire safety codes 
for all accessory dwelling units.  A municipality's design standards for accessory dwelling 
units must be clear and objective.  Accessory dwelling units within historical preservation 
districts must comply with historical preservation standards.