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Can I build an ADU in Kittery, Maine?

Kittery, York County · Ordinances checked 2026-10-01 · Reviewed · 10 cited sections

Allowed with a permit

Yes. The 2022 version of Kittery's Title 16 we reviewed allows one accessory dwelling unit per single-family lot in residential zones like R-S. If it meets the standards, the Code Enforcement Officer can approve it without a board hearing. The ADU can be up to 1,000 sq ft with no more than two bedrooms, and it can't be rented to the same party for less than 30 days.

ADUs per lot1, on a lot with one legal single-family home [4]
Max size1,000 sq ft (80% of the house if the house is 1,000 sq ft or smaller) [5]
Max bedrooms2 [6]
ApprovalCode Enforcement Officer, if all standards are met [3]
Parking1 on-site space in addition to the house's parking (tandem OK) [7]
Minimum rental period30 days to the same person or party [8]
Owner-occupancyOwner must live in one of the units (definition) [1]

Where ADUs are allowed

Kittery lists the ADU as a permitted use in its residential zones, including Residential-Suburban (R-S) [10], and an ADU "is allowed in all zoning districts where the use is permitted in Chapter 16.4" [2]. You can have only one per lot, and only on a lot with one legal single-family home [4]. The ADU can be inside the house or an existing accessory building, attached and sharing a common wall, or in a new accessory building, as long as zone setbacks are met [9]. One ADU is exempt from the zone's density limits.

Size and design

The unit can be no larger than 1,000 sq ft [5]. If the main house is 1,000 sq ft or smaller, the ADU can be at most 80% of the house's size, with no more than two bedrooms [6]. A unit built entirely inside the house can go ahead even if the house doesn't meet setbacks. An ADU can't go in an accessory building that encroaches on setbacks.

Owner-occupancy, rentals and parking

The definition of an ADU requires that "the owner of the property occupies one of the units" [1]. Only the parcel owner can apply. The ADU can't be rented to the same person or party for less than 30 days [8]. Violating that rule costs the unit its certificate of occupancy for at least 30 days, plus a $500 penalty. Each ADU needs one on-site parking space in addition to the house's parking [7].

Approval

An application that meets the size and development standards is approved administratively by the Code Enforcement Officer [3]. If you can't meet a unit standard, you can still ask the Board of Appeals for a miscellaneous variation. You must show adequate water and sewer or septic.

Check for newer rules

This answer comes from the Title 16 recodification as adopted January 24, 2022. Kittery has amended Title 16 since, including changes for Maine's 2022 housing law (LD 2003), so the current rules may differ. State law now bars towns from requiring parking for an ADU beyond what the house needs, so the extra-space rule may be overridden. The owner-occupancy requirement is still allowed until July 1, 2027, when state law ends it.

See how Kittery compares with 8+ other Maine towns on accessory dwelling units (adus) →

Next steps

  1. Ask Kittery Code Enforcement (207-475-1304) for the current ADU standards in Title 16 § 16.5.3, since the 2022 text may have been amended.
  2. Gather a plot plan showing setbacks, a floor plan with square footage and bedrooms, and proof of adequate water and sewer (Kittery Water District and Sewer Department letters) or a septic design from a Maine-licensed site evaluator.
  3. Submit the ADU application and fees to the Code Enforcement Officer, along with a building permit application.
  4. If your plan can't meet a unit standard, ask about a miscellaneous variation request with the Board of Appeals.

Common questions

Can I build an ADU in Kittery, Maine?
Yes. The 2022 version of Kittery's Title 16 we reviewed allows one accessory dwelling unit per single-family lot in residential zones. If it meets the standards, the Code Enforcement Officer can approve it without a board hearing. Kittery has amended Title 16 since, so ask for the current standards.
How big can an ADU be in Kittery, Maine?
Up to 1,000 sq ft with no more than two bedrooms. If the main house is 1,000 sq ft or smaller, the ADU can be at most 80% of the house's size.
Can I use an ADU as an Airbnb in Kittery, Maine?
Mostly no. An ADU can't be rented to the same person or party for less than 30 days, and breaking that rule costs the unit its certificate of occupancy for at least 30 days plus a $500 penalty.
Do I have to live on the property if I have an ADU in Kittery, Maine?
Yes, for now. The ADU definition requires that the owner occupy one of the units. The owner-occupancy requirement is still allowed until July 1, 2027, when state law ends it.
How much parking does an ADU need in Kittery, Maine?
The 2022 code requires one on-site space in addition to the house's parking. State law now bars towns from requiring parking for an ADU beyond what the house needs, so that rule may be overridden.

Maine's statewide ADU law

Under 30-A M.R.S. §4364-B (first passed as LD 2003 in 2022), a town must allow at least one accessory dwelling unit (ADU) on a lot with a single-family home anywhere homes are allowed. Towns had to comply by 2024.

Rules in effect now:

  • It can be inside the house, attached, or a new detached building.
  • One ADU per lot is exempt from density limits.
  • No extra parking can be required beyond what the house already needs.
  • Setbacks are the same as for the house.
  • Minimum size: the state building codes board set 160 sq ft in 2025. Towns may set a maximum size.
  • Before you can move in, you must show the ADU has adequate water and septic/sewer.
  • In the shoreland zone ADUs must meet shoreland rules, but towns can't ban them there outright.
  • Sprinklers aren't required unless the ADU is in or attached to a building with more than 2 units.

Coming July 1, 2027 (LD 1829 of 2025, pushed back by LD 2173 in 2026): towns can no longer require the owner to live on the property, ADUs must also be allowed next to 2- and 3-unit buildings, and towns can't require planning board approval for an ADU. Towns may still regulate short-term rentals in ADUs. Private covenants and HOA rules can be stricter.

State sources: 30-A M.R.S. §4364-B (Accessory dwelling units) · 30-A M.R.S. §4364 (implementation dates) · 25 M.R.S. §2463-B (sprinklers in ADUs) · LD 2173 (P.L. 2025, c. 733) status and chaptered law · Maine Office of Community Affairs, Housing Legislation Guidance (March 2026)

What the ordinance says

Exact text from Kittery's published ordinances. Section numbers are as printed in the source.

  1. § 16.3.2 Definitions: Accessory Dwelling Unit (ADU), Title 16 Land Use and Development Code as adopted January 24, 2022 (recodification), p. 43
    A dwelling unit which is part of an existing structure on the property where the owner of the property occupies one of the units.
  2. § 16.5.3.B(1) Applicability, Title 16 Land Use and Development Code as adopted January 24, 2022 (recodification), p. 214
    (1) An accessory dwelling unit is allowed in all zoning districts where the use is permitted in Chapter 16.4.
  3. § 16.5.3.C(2) Application for accessory dwelling unit, Title 16 Land Use and Development Code as adopted January 24, 2022 (recodification), p. 214
    (2) Applications for an accessory dwelling unit that meets the unit size standards and development standards contained in this article may be approved administratively and require approval by the Code Enforcement Officer.
  4. § 16.5.3.D(1)(a)-(b) Lot standards, Title 16 Land Use and Development Code as adopted January 24, 2022 (recodification), p. 214
    (a) Legal lot/residence. An accessory dwelling unit is allowed only on lots within the Town that contain one legal, single-family residence as the primary unit. (b) Number of accessory dwelling units per lot. No more than one accessory dwelling unit is permitted on a lot.
  5. § 16.5.3.D(2)(a) Unit size, Title 16 Land Use and Development Code as adopted January 24, 2022 (recodification), p. 216
    The size of an accessory dwelling unit must meet the minimum size for a dwelling unit as set by building code standards adopted and amended from time to time by Maine's Bureau of Building Codes and Standards, and be no larger than 1,000 square feet.
  6. § 16.5.3.D(2)(a) Unit size, Title 16 Land Use and Development Code as adopted January 24, 2022 (recodification), p. 216
    For principal dwelling units 1,000 square feet or smaller, an accessory dwelling unit may be no greater than 80% of the size of the principal dwelling unit, as measured in square feet. An accessory dwelling unit may have no more than two bedrooms.
  7. § 16.5.3.D(1)(f) Parking, Title 16 Land Use and Development Code as adopted January 24, 2022 (recodification), p. 215
    (f) Parking. Each accessory dwelling unit must have one on-site parking space in addition to the parking for the primary dwelling unit. Tandem parking is permitted.
  8. § 16.5.3.D(3) Use Standards, Title 16 Land Use and Development Code as adopted January 24, 2022 (recodification), p. 216
    (3) Use Standards. The accessory dwelling unit may not be rented to the same person or party for less than a thirty-day period.
  9. § 16.5.3.B(1) Applicability, Title 16 Land Use and Development Code as adopted January 24, 2022 (recodification), p. 214
    (a) Within an existing structure, either principal or accessory on the property; or (b) Attached to the existing principal structure, sharing a common wall; or (c) Within a new accessory structure constructed for this purpose on the property.
  10. § 16.4.11.B Residential-Suburban (R-S) permitted uses, Title 16 Land Use and Development Code as adopted January 24, 2022 (recodification), p. 99
    The following uses are permitted in the R-S Zone: (1) Accessory Dwelling Unit
This page summarizes Kittery's posted ordinances as of 2026-10-01. Ordinances are amended, and individual lots can have overlays, subdivision covenants, or HOA rules that are stricter. Confirm with Code Enforcement (Planning & Development) (207-475-1304 (Development Staff Clerk); CEOs 207-475-1305 / 207-475-1308) before you build. Spot an error?