York County · Maine
ADU rules in Kittery, ME
Kittery is the southernmost town in Maine, on the Piscataqua River across from Portsmouth.
This is a reference guide. Kittery is not on our service-area list, so call to ask whether we can take on a build there.
Town ADU rules
What’s allowed on your lot in Kittery.
Kittery’s ADU rules are in §16.5.3 of its land use code, last amended November 27, 2023.
- Size limit
- Building-code minimum; max 1,000 sq ft (80% of the house if the house is 1,000 sq ft or smaller); max 2 bedrooms
- Where it can go
- Within an existing house or accessory building, attached with a shared wall, or a new accessory building
- Owner on site
- No town rule (the parcel owner must apply)
- Parking
- No additional space; the main house must have on-site parking
- Approval
- Administrative approval by the Code Enforcement Officer; otherwise Board of Appeals miscellaneous variation
- Rentals
- No rentals to the same party for less than 30 days
- Water setback
- 100 ft from water bodies, tributary streams and wetlands (75 ft in MU-BI and MU-KF); ADUs not allowed in the Shoreland Overlay Zone
Allowed
- Attached or detachedADU allowed in all zones where the use is permitted in Ch. 16.4. It must be within an existing principal or accessory structure, attached to the principal structure sharing a common wall, or within a new accessory structure built for the purpose.§ 16.5.3B(1)(a)-(c)
- OtherADU must be located outside the Shoreland Overlay Zone (added 11-27-2023).§ 16.5.3B(1)(d)
- How manyOne ADU per lot in a limited growth area; up to two ADUs per lot in a targeted growth area (per the Comprehensive Plan).§ 16.5.3D(1)(b)
- SizeMinimum size is the building-code minimum for a dwelling unit; maximum 1,000 sq ft. If the principal dwelling is 1,000 sq ft or smaller, the ADU may be no more than 80% of its size. No more than two bedrooms.§ 16.5.3D(2)(a)
- LotLot must meet the zone's lot size for the principal residence (except legally nonconforming lots), but the ADU is exempt from the zone's density requirements. Zone setbacks apply; on nonconforming lots side/rear setbacks shrink by the percentage the lot is undersized. Building coverage stays as the zone requires.§ 16.5.3D(1)(c)-(d)
- LotADU may be built fully inside the principal residence even if the building does not meet setbacks, but not in an accessory building that encroaches on setbacks.§ 16.5.3D(2)(b)[2]-[3]
- SepticMust connect to adequate water and wastewater: sewer capacity letter and connection fees before CO; septic verified adequate under 30-A M.R.S. § 4221 with plans by a Maine-licensed site evaluator; written water district verification; or potable well test.§ 16.5.3D(1)(e)
- ParkingNo additional parking space required for the ADU, but the primary dwelling must have on-site parking.§ 16.5.3D(1)(f)
- OtherOn a privately maintained road or right-of-way, the applicant must submit written consent from the road/homeowners association or the parties responsible for maintenance.§ 16.5.3D(1)(g)
- ApprovalApplication by the parcel owner to the Code Enforcement Officer; an ADU meeting the standards may be approved administratively by the CEO. One that does not may be allowed by the Board of Appeals as a miscellaneous variation (§ 16.2.12).§ 16.5.3C(1)-(3), D(4)
- RentalsADU may not be rented to the same person or party for less than 30 days. Violation: loss of the CO for at least 30 days and a $500 penalty. Units with a CO or active permit as of April 28, 2020 are exempt from this use standard.§ 16.5.3D(3), D(5), B(2)
- OtherIn C-1 and C-3, adding an ADU to a single-family residence is exempt from the multi-unit design standards.§ 16.4.19, § 16.4.21 (design standards [7])
- ShorelandTown Shoreland Overlay Zone (OZ-SL) under 38 M.R.S.A. §§ 435-449: 250 ft from coastal wetlands and certain freshwater wetlands; 75 ft from tributary streams (Stream Protection OZ-SL-75). All new principal and accessory structures set back at least 100 ft from the normal high-water line of water bodies, tributary streams and the upland edge of coastal or freshwater wetlands; 75 ft in MU-BI and MU-KF. Patios/decks up to 500 sq ft: 75 ft. Devegetated area max 20% of the lot within the zone (60% MU-BI/MU-KF; 70% C-1/C-2/C-3/B-L/B-L1/IND). Shoreland lot size/shore frontage table by base zone (e.g., R-RL 40,000 sq ft, 150 ft/100 ft). The zones' shoreland permitted-use lists do not include ADUs.§ 16.4.28C, E(1)-(3); Table 16.5.30
- State lawThe town text bans ADUs anywhere in its Shoreland Overlay Zone. Maine law says a town may not categorically prohibit ADUs in the shoreland zone.30-A M.R.S. §4364-B(5)
Not allowed
- Not allowedNo ADU in the Shoreland Overlay Zone.§ 16.5.3B(1)(d)
- Not allowedMore than one ADU on a lot in a limited growth area (two allowed only in a targeted growth area).§ 16.5.3D(1)(b)
- Not allowedADU in an accessory building that encroaches on yard setbacks.§ 16.5.3D(2)(b)[3]
- Not allowedRenting the ADU to the same party for less than 30 days.§ 16.5.3D(3)
- Not allowedMore than two bedrooms in an ADU.§ 16.5.3D(2)(a)
Read 2026-11-15 from Town of Kittery Code, Title 16: Land Use and Development Code (Ch. 16.4 Land Use Zone Regulations; Ch. 16.5 General Performance Standards, § 16.5.3 Accessory dwelling units) (Title 16 adopted 1-24-2022 by Ord. No. 22-01; § 16.5.3 [Added 11-27-2023] / [Amended 11-27-2023]; § 16.4.28 [Amended 11-27-2023; 12-9-2024]. ecode360 code version 2025-12-08. One pending 'New Law' (adopted 2026-08-24, Ch 16.2, 16.3, 16.5) not yet codified; its PDF (LF2872444) covers § 16.5.11 floodplain/coastal hazard and contains no ADU text. Read live 2026-11-15.). Anything not listed here, we check with the Kittery land-use office for your lot.
Setbacks
Front, side and rear in Kittery.
Maine 30-A M.R.S. §4364-B - at least one ADU with a single-family home; from July 1, 2027, also with a two- or three-unit building, and at least three units per lot
Kittery's dimensional table, as printed in the ordinance.
| District | Front | Side | Rear | Lot / cover / height |
|---|---|---|---|---|
| R-RLprimaryResidential — Rural§ 16.4.10D(2). R-RL frontage 150 feet. R-RL accessory buildings: not separately stated. | 40 feet | 20 feet | 20 feet | 40,000 square feet (min. net residential acreage per dwelling unit 40,000 square feet) · 15% (building) · Height 35 feet |
| R-SResidential — Suburban§ 16.4.11D(2). R-S frontage 150 feet unless reduced per Note A. R-S accessory buildings: not separately stated. | 40 feet | 15 feet | 15 feet | 40,000 square feet without public sewage disposal; 30,000 square feet with public sewage disposal (may be reduced per Note A) · 20% (building) · Height 35 feet |
| R-KPVResidential — Kittery Point Village§ 16.4.12D(2). R-KPV frontage 150 feet unless reduced per Note A (not less than 100 feet). R-KPV accessory buildings: not separately stated. | 40 feet | 15 feet | 15 feet | 40,000 square feet (net residential acreage 40,000 sq ft per unit, with exemption for lots conforming before October 25, 2012) · 20% (building) · Height 35 feet |
| R-UResidential — Urban§ 16.4.13D(2). R-U frontage 100 feet. R-U accessory buildings: same as principal (stated for all buildings). | 30 feet (all buildings) | 15 feet (all buildings) | 15 feet (all buildings) | 20,000 square feet · 20% (building) · Height 35 feet |
| R-VResidential — Village§ 16.4.14D(1). R-V frontage 50 feet. R-V accessory buildings: side and rear 3 feet for residential accessory buildings at least 4 feet behind the predominant rear line of the principal building. | 15 feet | 10 feet (dwellings/structures) | 15 feet (dwellings/structures) | 6,000 square feet (min. net residential acreage per dwelling unit 4,000 square feet) · Both printed: maximum structure coverage 40%; maximum building coverage 20% · Height 35 feet (principal); 15 feet for accessory structures closer than 10 feet to a lot line |
| R-RCResidential — Rural Conservation§ 16.4.15D(2). R-RC frontage 200 feet. R-RC accessory buildings: not separately stated. | 40 feet | 20 feet | 20 feet | 80,000 square feet · 6% (building) · Height 35 feet |
| B-LBusiness — Local§ 16.4.17D(1). B-L frontage none. B-L accessory buildings: not separately stated. | maximum 20 feet (front setback is a maximum) | 10 feet | 10 feet | none (lot area per dwelling unit: 20,000 sq ft net residential acreage on on-site sewage; 3,000 sq ft per unit on public sewer with no State Road/Route 1 Bypass frontage) · No maximum impervious surface; minimum 15% open space · Height 40 feet |
| B-L1Business — Local 1§ 16.4.18D(1). B-L1 frontage 50 feet. B-L1 accessory buildings: not separately stated. | maximum 20 feet (front setback is a maximum) | 10 feet | 10 feet | none (lot area per dwelling unit 2,500 sq ft when no State Road or Shapleigh Road frontage) · 70% (impervious surface; Planning Board may allow more); minimum 15% landscaped or natural · Height 40 feet |
| MUMixed-Use§ 16.4.23B(2), D. MU frontage 250 feet on Route 1, Haley Road, Lewis Road or Cutts Road; 150 feet on other streets. MU accessory buildings: not separately stated. | 30 feet | 30 feet | 30 feet | 200,000 square feet with Route 1 frontage; 80,000 square feet without · No coverage % printed; 35% of each lot must be open space · Height 40 feet |
| MU-BIMixed-Use — Badger Island§ 16.4.24D(1). MU-BI frontage 50 feet. MU-BI accessory buildings: not separately stated. | five feet | 10 feet | 10 feet | 6,000 square feet (3,000 sq ft lot area per dwelling unit) · No coverage % printed; minimum open space 40% · Height 40 feet |
| MU-KFMixed-Use — Kittery Foreside§ 16.4.25D. MU-KF frontage zero feet. MU-KF accessory buildings: not separately stated. | zero feet on Government Street east of Jones Avenue and Wallingford Square; 10 feet on other streets | 10 feet | 10 feet | 5,000 square feet (5,000 sq ft lot area per dwelling unit) · 60% (building); minimum open space 40% · Height 40 feet (35 feet above average grade on lots abutting tidal waters) |
Verified 2026-11-15 against Town of Kittery Code, Title 16: Land Use and Development Code (Ch. 16.4 Land Use Zone Regulations; Ch. 16.5 General Performance Standards, § 16.5.3 Accessory dwelling units). Towns amend ordinances, so confirm with the land-use office before you build. Official source
FAQ
ADUs in Kittery.
- How big can an ADU be in Kittery?
- Building-code minimum; max 1,000 sq ft (80% of the house if the house is 1,000 sq ft or smaller); max 2 bedrooms, per § 16.5.3D(2)(a) as read 2026-11-15.
- Does the owner have to live on the lot in Kittery?
- No town rule (the parcel owner must apply) (Town of Kittery Code, Title 16: Land Use and Development Code (Ch. 16.4 Land Use Zone Regulations; Ch. 16.5 General Performance Standards, § 16.5.3 Accessory dwelling units)).
- Can an ADU in Kittery be detached?
- Within an existing house or accessory building, attached with a shared wall, or a new accessory building, under § 16.5.3B(1)(a)-(c).
Planning an ADU in Kittery?
Call (978) 987-0089 and we will say whether we can build there. See the ADU models