Can I build an ADU in Ogunquit, Maine?
Yes. Under the 2023 rewrite of Ogunquit's ADU section, you can add one accessory dwelling unit, attached or freestanding, to a single-family home. It must be 190 to 700 sq ft, the main house must be owner-occupied, and you need Design Review approval and a certificate of occupancy before anyone moves in.
| Minimum ADU size | 190 sq ft [1] |
| Maximum ADU size | 700 sq ft [1] |
| ADUs per lot | 1 [2] |
| Attached or detached | Either: attached to the house or freestanding [3] |
| Owner occupancy | Primary dwelling must be owner-occupied [4] |
| Minimum lease if rented | 12 consecutive months; no short-term rentals [4] |
| Approvals | Building permits, Design Review approval (all districts), certificate of occupancy [5] |
| Setbacks (attached ADU) | Same as the single-family house [6] |
Source and date
This answer relies on the certified text of the §225-9.1 rewrite that went to voters on June 13, 2023. We could not download the current codified Chapter 225 from eCode360, so we haven't confirmed that the amendment passed as written or whether it has changed since. The certified copy is a redline. We checked the strike-through and underline marks in the PDF to separate deleted wording from added wording; quotes below may still show an old word next to its replacement.
What's allowed
An ADU is allowed as an accessory use to a single-family dwelling. It may be inside the house, attached to it, or freestanding from it [3]. Only one ADU is permitted per lot [2]. The unit must be at least 190 square feet and no larger than 700 square feet [1]. The 2020 code's limit of 40% of the house or 800 sq ft, its ban on new exterior construction, and its affordable-rent requirement are struck through in the certified text. The lot must still be a conforming lot or a legal nonconforming lot.
Occupancy and rentals
The main house must be owner-occupied. If the ADU is leased, the lease must run at least 12 consecutive months, and the ADU can't be used as a short-term rental [4]. Maine's ADU law bars towns from requiring owner occupancy starting July 1, 2027, so the owner-occupancy rule may not be enforceable after that date. The short-term rental ban is still allowed under state law.
Setbacks and utilities
An ADU inside or attached to the house must meet the same setback and dimensional requirements as the house. A unit in a garage or accessory building that already existed on July 1, 2023 uses that structure's setbacks [6]. Before a certificate of occupancy is issued, you must give the town written proof that the ADU has adequate water and wastewater service. For a septic system, that means a local plumbing inspector has confirmed the system is adequate [8].
Parking
The 2020 code required one extra off-street parking space for the unit [7]. That rule is struck through in the 2023 certified text, so the new section has no extra parking requirement (state law also bars one).
Approvals
You need all required construction permits, Design Review approval in every zoning district, and a certificate of occupancy before the ADU is occupied [5]. Under state law, starting July 1, 2027, towns can't require planning board approval for an ADU, which may affect the Design Review step.
See how Ogunquit compares with 8+ other Maine towns on accessory dwelling units (adus) →
Next steps
- Ask the Ogunquit Code Enforcement Office (Land Use Director/CEO) for the current §225-9.1 text, since we could not confirm the adopted 2023 version.
- Prepare plans showing the ADU's floor area (190 to 700 sq ft) and its setbacks, and apply for a building permit.
- Apply to the Planning Board for Design Review approval, which the 2023 text requires in all districts.
- Get written proof of adequate water and sewer or septic (a plumbing inspector's sign-off for septic) before you request a certificate of occupancy.
Common questions
- Can I build an ADU in Ogunquit, Maine?
- Yes. Under the 2023 rewrite of Ogunquit's ADU section, you can add one accessory dwelling unit, attached or freestanding, to a single-family home. You need Design Review approval and a certificate of occupancy before anyone moves in. We couldn't confirm the amendment passed as written.
- How big can an ADU be in Ogunquit, Maine?
- An ADU must be at least 190 square feet and no larger than 700 square feet under the 2023 certified text. Only one ADU is permitted per lot, and it can be inside the house, attached to it, or freestanding.
- Does the owner have to live on the property to have an ADU in Ogunquit, Maine?
- Yes, under the 2023 text the main house must be owner-occupied. Maine's ADU law bars towns from requiring owner occupancy starting July 1, 2027, so this rule may not be enforceable after that date.
- Can I use an ADU as an Airbnb in Ogunquit, Maine?
- No. An ADU can't be used as a short-term rental in Ogunquit. If you lease it, the lease must run at least 12 consecutive months.
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.
What the ordinance says
- §225-9.1A (2023 certified text), Chapter 225 Zoning §225-9.1 Accessory Dwelling Units (certified text for June 13, 2023 vote), p. 2
A. An accessory dwelling unit must meet a minimum size of 190 square feet and shall be no larger than 700 square feet.
- §225-9.1G (2023 certified text), Chapter 225 Zoning §225-9.1 Accessory Dwelling Units (certified text for June 13, 2023 vote), p. 3
G. Only one accessory dwelling unit shall be permitted per lot.
- §225-9.1 (2023 certified text), Chapter 225 Zoning §225-9.1 Accessory Dwelling Units (certified text for June 13, 2023 vote), p. 2
attached to the dwelling or freestanding from the main dwelling shall be permitted, provided all of the following conditions are met:
- §225-9.1C (2023 certified text), Chapter 225 Zoning §225-9.1 Accessory Dwelling Units (certified text for June 13, 2023 vote), p. 2
C. The primary dwelling is owner occupied. If leased the accessory dwelling unit shall be occupied by the lessee for a duration of not less than twelve consecutive months. Accessory dwelling units shall not be leased or rented as short-term rentals.
- §225-9.1E (2023 certified text), Chapter 225 Zoning §225-9.1 Accessory Dwelling Units (certified text for June 13, 2023 vote), p. 3
E. All required permits are obtained for construction of the accessory apartment dwelling unit, including a Design Review approval in all zoning districts
- §225-9.1F (2023 certified text), Chapter 225 Zoning §225-9.1 Accessory Dwelling Units (certified text for June 13, 2023 vote), p. 3
F. Any accessory dwelling unit located within the same structure as a single-family dwelling unit or attached to or sharing a wall with a single-family dwelling unit, the setback requirements and dimensional requirements must be the same as the setback requirements and dimensional requirements of the single-family dwelling unit, except for an accessory dwelling unit permitted in an existing accessory building or secondary building or garage as of July 1, 2023, in which case the requisite setback requirements for such a structure apply.
- §225-9.1E (2020 code, superseded), Ogunquit Zoning Ordinance, Chapter 225 (town PDF), p. 99
E. One off-street parking space is provided for the accessory apartment, in accordance with the dimensional and design requirements of this chapter.
- §225-9.1B (2023 certified text), Chapter 225 Zoning §225-9.1 Accessory Dwelling Units (certified text for June 13, 2023 vote), p. 2
B. The owner of an accessory dwelling unit must provide written verification to the municipality that the accessory dwelling unit is connected to adequate potable water and wastewater services before the municipality may issue a certificate of occupancy.