How big can an ADU be in Kennebunkport?

190 to 800 sq ft of living area, per §240-7.1.D as read 2026-11-15.

Does the owner have to live on the lot in Kennebunkport?

No owner rule; ADU must be someone's primary residence (more than 6 months a year) (§240-7.1.G).

Can an ADU in Kennebunkport be detached?

Within, attached to, or detached from a single-family dwelling, under §240-7.1 (preamble); §240-2.2 "Apartment, accessory".

York County · Maine

ADU rules in Kennebunkport, ME

Kennebunkport is a York County coastal town at the mouth of the Kennebunk River.

Kennebunkport is in our service area. This page covers what the town ordinance says about ADUs.

Call (978) 987-0089

Town ADU rules

What’s allowed on your lot in Kennebunkport.

Kennebunkport calls an ADU an accessory apartment and permits one in every zone, from 190 to 800 sq ft. It must be someone’s primary residence.

Size limit: 190 to 800 sq ft of living area
Where it can go: Within, attached to, or detached from a single-family dwelling
Owner on site: No owner rule; ADU must be someone's primary residence (more than 6 months a year)
Parking: Not counted as a unit for residential parking standards
Approval: Permitted use in every zone; application needs a site plan and floor plan
Rentals: Short-term rental not allowed
Water setback: 75 ft from water bodies and wetlands (25 ft in Dock Square and Riverfront; 250 ft in Resource Protection)

Allowed

Attached or detachedThe town calls ADUs 'accessory apartments': a self-contained unit within, attached to, or detached from a single-family dwelling on the same parcel. ADUs are allowed only on a lot containing one or more single-family dwellings.§240-7.1 (preamble); §240-2.2 "Apartment, accessory"
How manyNo more than one accessory apartment on a lot containing one or more single-family dwellings.§240-7.1.F
SizeLiving area at least 190 sq ft and at most 800 sq ft.§240-7.1.D
HeightNo living space on a third story unless it meets the Building Code's minimum life-safety requirements. Zone height limits: 2 1/2 stories or 35 ft in Village Residential, Village Residential East, Cape Arundel, Free Enterprise and Farm and Forest; 2 1/2 stories or 30 ft in Dock Square, Riverfront, Goose Rocks and the Cape Porpoise zones.§240-7.1.D; §240-6.2
Owner on siteNo owner-occupancy rule. The accessory apartment itself must be occupied as a primary residence, defined as more than six months per year.§240-7.1.G
RentalsAn accessory apartment may not operate as a short-term rental.§240-7.1.G
LotA complying accessory apartment is exempt from the zone's minimum lot area, minimum lot width and minimum net residential area per dwelling unit. It is not a two-family dwelling or multiplex, and it is not counted as a dwelling unit for residential parking (§240-6.10), road construction (§240-6.14), growth management permits (§240-11.12), the state subdivision definition, or net residential area. A non-complying one is a full dwelling unit.§240-7.1 (preamble)
ParkingBecause a complying accessory apartment is not counted as a dwelling unit under the residential parking standards, no parking is added for it. The house's own requirement is 1 space for a studio to two-bedroom unit and 2 spaces for three or more bedrooms.§240-7.1 (preamble); §240-6.10
ApprovalAccessory apartment is listed as a Permitted Use in all ten zone use tables (Village Residential, Village Residential East, Dock Square, Riverfront, Cape Arundel, Goose Rocks, Cape Porpoise East/West, Cape Porpoise Square, Free Enterprise, Farm and Forest). The request needs a site plan (owner, deed reference, lot boundaries and dimensions, building and parking locations and setbacks) and a floor plan of the whole building.§240-7.1.A, B; §§240-4.3 to 240-4.12
DesignFor an accessory apartment within or attached to a house, the dwelling may have only one front entrance; other entrances go on the side or rear. A shared foyer entrance is allowed.§240-7.1.C
DesignA detached or attached accessory apartment must follow low-impact-development stormwater best practices (LID Guidance Manual for Maine Communities, Maine DEP, Sep. 21, 2007).§240-7.1.I
SepticOn town sewer, the Sewer Department must approve. On septic and private wells, the Maine Subsurface Wastewater Disposal Rules apply; a licensed site evaluator must evaluate existing septic systems for condition and capacity; a reserve area is required; septic systems must be pumped biannually, with documentation to the Town on request.§240-7.1.H
LotIn the Shoreland Zone, an accessory apartment is allowed only if the lot has at least double the required minimum lot size and shore frontage. The shoreland minimum for residential use is 40,000 sq ft per dwelling unit, with 150 ft shore frontage on tidal areas and 200 ft on nontidal areas.§240-7.1.E; §240-4.16.A
OtherAn accessory apartment cannot be independently conveyed except as permitted by law. It must meet all other Code requirements, including Article 6 and shoreland zoning.§240-7.1.J, K
ShorelandAll structures in the Shoreland Zone must be set back at least 75 ft from the normal high-water mark of water bodies and tributary streams and from the upland edge of a wetland. The setback is 25 ft in the Dock Square and Riverfront Zones and 250 ft in Resource Protection, except for objects specifically allowed there. Shoreland lot coverage of all structures, parking and nonvegetated surfaces is capped at 20% (70% in Dock Square). The residential shoreland minimum is 40,000 sq ft per dwelling unit, with 150 ft shore frontage on tidal areas and 200 ft on nontidal areas. In the Shoreland Zone, single-family and two-family dwellings need Planning Board approval (§240-4.14.B(12)).§240-4.17; §240-4.16.A; §240-4.14.B(12)

Not allowed

Not allowedNo second accessory apartment on a lot.§240-7.1.F
Not allowedAccessory apartment may not be independently conveyed except to the extent permitted by law.§240-7.1.J
Not allowedNo short-term rental of the accessory apartment.§240-7.1.G
Not allowedNo accessory apartment in the Shoreland Zone unless the lot has at least double the required minimum lot size and shore frontage.§240-7.1.E
Not allowedAccessory apartments are allowed only on lots with single-family dwellings (not with two-family or multiplex).§240-7.1 preamble

Read 2026-11-15 from Town of Kennebunkport Code, Chapter 240: Land Use (Land Use Ordinance) (Chapter history: adopted 3-6-1972, amended through 11-6-2018, later amendments noted per section. §240-7.1 [Amended 11-3-2020; 6-13-2023; 6-11-2024]. Zone sections amended through 11-4-2025. Dimensional table [Amended 6-10-2025]. eCode360 shows legislation through 06-09-2026; read live 2026-11-15.). Anything not listed here, we check with the Kennebunkport land-use office for your lot.

Setbacks

Front, side and rear in Kennebunkport.

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

Kennebunkport's dimensional table, as printed in the ordinance.

District	Front	Side	Rear	Lot / cover / height
VRprimaryVillage Residential240 Attachment 1, Table of Dimensional Requirements [Amended 6-10-2025]; uses from §240-4.x tables; height §240-6.2; §240-4.3. VR frontage 100 ft (minimum lot width).	20 ft	15 ft	15 ft	40,000 sq ft (net residential area 40,000 sq ft/unit) · 20% (structures; in Shoreland Zone includes nonvegetated surfaces) · Height 35 ft (2 1/2 stories)
VREVillage Residential East240 Attachment 1, Table of Dimensional Requirements [Amended 6-10-2025]; uses from §240-4.x tables; height §240-6.2; §240-4.4. VRE frontage 100 ft (minimum lot width).	20 ft	15 ft	15 ft	40,000 sq ft (net 40,000 sq ft/unit) · 20% (structures) · Height 35 ft (2 1/2 stories)
RFRiverfront240 Attachment 1, Table of Dimensional Requirements [Amended 6-10-2025]; uses from §240-4.x tables; height §240-6.2; §240-4.6. RF frontage 100 ft (minimum lot width).	20 ft	15 ft	15 ft	20,000 sq ft (net 20,000 sq ft/unit) · 20% (structures) · Height 30 ft (2 1/2 stories)
CACape Arundel240 Attachment 1, Table of Dimensional Requirements [Amended 6-10-2025]; uses from §240-4.x tables; height §240-6.2; §240-4.7. CA frontage 100 ft (minimum lot width).	20 ft	15 ft	15 ft	40,000 sq ft (net 40,000 sq ft/unit) · 20% (structures) · Height 35 ft (2 1/2 stories)
GRGoose Rocks240 Attachment 1, Table of Dimensional Requirements [Amended 6-10-2025]; uses from §240-4.x tables; height §240-6.2; §240-4.8. GR frontage 100 ft (minimum lot width).	20 ft	15 ft	15 ft	40,000 sq ft (net 40,000 sq ft/unit) · 20% (structures) · Height 30 ft (2 1/2 stories)
CPE/CPWCape Porpoise East and Cape Porpoise West240 Attachment 1, Table of Dimensional Requirements [Amended 6-10-2025]; uses from §240-4.x tables; height §240-6.2; §240-4.9. CPE/CPW frontage 100 ft (minimum lot width).	20 ft	15 ft	15 ft	20,000 sq ft (net 20,000 sq ft/unit) · 20% (structures) · Height 30 ft (2 1/2 stories)
CPSCape Porpoise Square240 Attachment 1, Table of Dimensional Requirements [Amended 6-10-2025]; uses from §240-4.x tables; height §240-6.2; §240-4.10. CPS frontage 100 ft (minimum lot width).	20 ft	15 ft	15 ft	20,000 sq ft (net 20,000 sq ft/unit) · 20% (structures) · Height 30 ft (2 1/2 stories)
FEFree Enterprise240 Attachment 1, Table of Dimensional Requirements [Amended 6-10-2025]; uses from §240-4.x tables; height §240-6.2; §240-4.11. FE frontage 100 ft (minimum lot width).	20 ft	15 ft	15 ft	40,000 sq ft (net 40,000 sq ft/unit) · 20% (structures) · Height 35 ft (2 1/2 stories)
FFFarm and Forest240 Attachment 1, Table of Dimensional Requirements [Amended 6-10-2025]; uses from §240-4.x tables; height §240-6.2; §240-4.12. FF frontage 200 ft (minimum lot width).	20 ft	15 ft	15 ft	3 acres / 130,680 sq ft (net 130,680 sq ft/unit) · 10% (structures) · Height 35 ft (2 1/2 stories)

Verified 2026-11-15 against Town of Kennebunkport Code, Chapter 240: Land Use (Land Use Ordinance). Towns amend ordinances, so confirm with the land-use office before you build. Official source

FAQ

ADUs in Kennebunkport.

How big can an ADU be in Kennebunkport?: 190 to 800 sq ft of living area, per §240-7.1.D as read 2026-11-15.
Does the owner have to live on the lot in Kennebunkport?: No owner rule; ADU must be someone's primary residence (more than 6 months a year) (§240-7.1.G).
Can an ADU in Kennebunkport be detached?: Within, attached to, or detached from a single-family dwelling, under §240-7.1 (preamble); §240-2.2 "Apartment, accessory".

Planning an ADU in Kennebunkport?

Call (978) 987-0089 and we will read the ordinance against your lot. See the ADU models

Get a quote Call (978) 987-0089