Section 100-5-3 - DWELLING UNIT ALLOWANCEA.GENERALThis section requires municipalities to allow multiple dwelling units on lots where housing is allowed beginning on July 1, 2023, subject to the requirements below. The requirements listed in Section 3 apply to municipalities with and without zoning. Private, state or local standards such as homeowners' association regulation, deed restrictions, lot size, set back, density, septic requirements, minimum lot size, additional parking requirements, growth ordinance permits, shoreland zoning and subdivision law, may also apply to lots.
B.REQUIREMENTS1. Dwelling Unit Allowancea) If a lot does not contain an existing dwelling unit, municipalities must allow up to four (4) dwelling units per lot if the lot is located in an area in which housing is allowed, meets the requirements in 12 M.R.S. Ch. 423-A, and is: i. Located within a designated growth area consistent with 30-A M.R.S. §4349 A(1)(A)-(B); orii. Served by both a public, special district or other centrally managed water system and a public, special district or other comparable sewer system in a municipality without a comprehensive plan.b) If a lot does not contain an existing dwelling unit and does not meet i. or ii. above, a municipality must allow up to two (2) dwelling units per lot located in an area in which housing is allowed, provided that the requirements in 12 M.R.S. Ch. 423-A are met. The two (2) dwelling units may be (1) within one structure; or (2) separate structures.c) If a lot contains one existing dwelling unit, a municipality must allow the addition of up to two (2) additional dwelling units:i. One within the existing structure or attached to the existing structure;ii. One detached from the existing structure; ord) If a lot contains two existing dwelling units, no additional dwelling units may be built on the lot unless allowed under local municipal ordinance.e) A municipality may allow more units than the minimum number of units required to be allowed on all lots that allow housing.2. Zoning With respect to dwelling units allowed under this Section, municipalities with and without zoning ordinances must comply with the following:
a) If more than one dwelling unit has been constructed on a lot as a result of the allowance pursuant to this Section, the lot is not eligible for any additional units or increases in density except as allowed by the municipality. Municipalities have the discretion to determine if a dwelling unit or accessory dwelling unit has been constructed on a lot for purposes of this provision.b) Municipalities may establish a prohibition or an allowance for lots where a dwelling unit in existence after July 1, 2023, is torn down and an empty lot results.3. Dimensional and Setback Requirements a) A municipal ordinance may not establish dimensional requirements or setback requirements for dwelling units allowed pursuant to this Section that are more restrictive than the dimensional requirements or setback requirements for single-family housing units.4. A municipality may establish requirements for a lot area per dwelling unit as long as the additional dwelling units required for each additional dwelling unit is proportional to the lot area per dwelling unit of the first unit. Water and Wastewater
a) The municipality must require an owner of a proposed housing structure to provide written verification that each proposed structure is to be connected to adequate water and wastewater services prior to certification of the development for occupancy or similar type of approval process. Written verification must include the following: i. If a housing structure 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;ii. If a housing structure is connected to a septic system, proof of adequate sewage disposal for subsurface wastewater. The septic system must be verified as adequate by a local plumbing inspector pursuant to 30-A M.R.S. §4221. Plans for a subsurface wastewater disposal must be prepared by a licensed site evaluator in accordance with 10-144 C.M.R. Ch. 241, Subsurface Wastewater Disposal Rules.iii. If a housing structure is connected to a public, special district or other centrally managed water system, 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; andiv. If a housing structure is connected to a well, proof of access to potable water, including the standards outlined in 01-672 C.M.R. Ch. 10 section 10.25(J), Land Use Districts and Standards. Any test of an existing well or proposed well must indicate that the water supply is potable and acceptable for domestic use.C.MUNICIPAL IMPLEMENTATIONIn adopting an ordinance, a municipality may:
1. Establish an application and permitting process for dwelling units;2. Impose fines for violations of building, site plan, zoning, and utility requirements for dwelling units; and3. Establish alternative criteria that are less restrictive than the requirements of Section 3(B)(4) for the approval of a dwelling units only in circumstances in which the municipality would be able to provide a variance pursuant to 30-A M.R.S. §4353(4)(A), (B), or (C).