Town Permit Guide

Home › Maine › Camden › Accessory Dwelling Units (ADUs)

Can I build an ADU in Camden, Maine?

Camden, Knox County · Ordinances checked 2026-10-01 · Reviewed · 10 cited sections

Allowed with a permit

Yes. Camden calls an ADU an "accessory apartment": one unit of 600 sq ft or less on a lot with a single-family home, allowed in the Rural 1 and 2, Coastal Residential, Village Extension and Traditional Village districts, among others. Both units must be someone's primary residence, the apartment needs one parking space, and you need a building permit from the Code Enforcement Officer. Our copy of the zoning ordinance only runs through June 2022, so confirm the current rules.

Maximum size600 sq ft gross living area [1]
Number allowedOne accessory apartment per single-family lot [2]
Occupancy ruleBoth units must be the occupants' primary residence (6 months plus 1 day) [3]
Extra lot area neededNone in most districts; 20,000 sq ft in Village Extension (VE) where there is no public sewer [5]
Parking1 off-street space (none required in B-1 and B-TH) [6]
ApprovalBuilding and/or use permit from the Code Enforcement Officer [9]

What counts as an accessory apartment

Camden's zoning calls an ADU an accessory apartment: a dwelling unit of 600 sq ft or less of gross living area on a lot with a single-family home [1]. A lot can have only one, and both the house and the apartment must be the primary residence of the people living there [2]. "Primary residence" means the same resident lives there for at least six consecutive months plus one day [3]. In practice, neither unit can be a short-term or seasonal rental. The ordinance doesn't say whether the apartment has to be inside the house, attached, or in a separate building.

Where it's allowed

Accessory apartments are a permitted use in the Traditional Village (V) district [4], the Coastal Residential (CR) district [8], and also in Rural 1, Rural 2, Village Extension and the B-2, B-3 and B-4 business districts. In most of these districts you don't need extra lot area for the apartment [5]. The exception is the Village Extension district on lots without public sewer: its lot-area table has a Sewer column ("No increase in lot area required") and a No Sewer column (20,000 sq ft per accessory apartment) [10]. The apartment still has to meet the zone's normal setbacks and coverage limits. The B-1, B-H and B-TH districts allow single-family homes but don't list accessory apartments.

Other requirements

  • Parking: one off-street space for the apartment, except in the B-1 and B-TH districts, which are exempt [6].
  • Building code and septic: the apartment must meet all building codes and the state Subsurface Wastewater Rules. In the shoreland zone it must also meet the shoreland minimum lot sizes [7].
  • Permit: a building and/or use permit from the Code Enforcement Officer is required before work starts [9].

State law and stale text

Our copy of the zoning ordinance includes amendments only through June 14, 2022. Chapter 290 has been amended since then, so the current rules may differ. Maine's ADU law (30-A M.R.S. §4364-B) bars towns from requiring parking for an ADU beyond what the house needs, so state law may override Camden's one-space requirement. State law also requires towns to allow one ADU on single-family lots wherever housing is allowed and exempts it from density limits, which may override the Village Extension no-sewer lot-area rule and the omission of accessory apartments from B-1, B-H and B-TH.

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

Next steps

  1. Confirm your zoning district on Camden's zoning map and check that your lot has a single-family home.
  2. Plan a unit of no more than 600 sq ft that meets your zone's setbacks, with one off-street parking space (unless you're in B-1 or B-TH).
  3. If you're on septic, have the system checked for the added unit; in the shoreland zone, check the shoreland lot-size rules.
  4. Apply for a building permit with Camden's Planning, Development and Code Enforcement office (207-236-3353 ext. 7112) and ask whether any post-2022 amendments apply.

Common questions

Can I build an ADU in Camden, Maine?
Yes. Camden calls an ADU an accessory apartment: one unit of 600 sq ft or less of gross living area on a lot with a single-family home. It's allowed in districts including Rural 1 and 2, Coastal Residential, Village Extension and Traditional Village. Our copy of the ordinance runs only through June 2022, so confirm current rules.
How big can an accessory apartment be in Camden, Maine?
600 square feet of gross living area or less, and only one is allowed per single-family lot. In most districts no extra lot area is needed.
Does an ADU need a permit in Camden, Maine?
Yes. You need a building and/or use permit from the Code Enforcement Officer before work starts. The apartment also needs one off-street parking space, except in the B-1 and B-TH districts.
Can I rent an ADU short-term in Camden, Maine?
Practically no. Both the house and the apartment must be the primary residence of the people living there, meaning the same resident lives there at least six consecutive months plus one day. Neither unit can be a short-term or seasonal rental in practice.

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 Camden's published ordinances. Section numbers are as printed in the source.

  1. §290-3.2, Definitions: Accessory apartment, Zoning Ordinance (Chapter 290) - town PDF, p. 7
    ACCESSORY APARTMENT — A dwelling unit of 600 square feet or less, gross, of living area, on a lot with a single-family dwelling otherwise too small in area to accommodate an additional dwelling.
  2. §290-3.2, Definitions: Accessory apartment (A)-(B), Zoning Ordinance (Chapter 290) - town PDF, p. 7
    A. A lot having a single-family dwelling shall contain no more than one accessory apartment; B. Both units shall serve as the primary residence of the occupants.
  3. §290-3.2, Definitions: Accessory apartment, Zoning Ordinance (Chapter 290) - town PDF, p. 7
    For the purpose of this provision, "primary residence" shall mean a dwelling unit occupied by the same resident for a minimum of six consecutive months, plus one day.
  4. §290-8.7B(3), Traditional Village District permitted uses, Zoning Ordinance (Chapter 290) - town PDF, p. 66
    (3) The following residential uses: (a) Single-family dwellings. (b) Two-family dwellings. (c) Multifamily dwellings. (d) Open space residential developments that meet the standards of ArticleIX. (e) Accessory apartments.
  5. §290-8.7E(2), Traditional Village space and bulk standards, Zoning Ordinance (Chapter 290) - town PDF, p. 68
    Accessory apartments No increase in lot area required (see definition)
  6. §290-10A.5B(1)(b), Off-street parking, Zoning Ordinance (Chapter 290) - town PDF, p. 133
    (b) Accessory apartments: one space per unit, except for those in the B-1 and B-TH, which are exempt from off-street parking requirements.
  7. §290-3.2, Definitions: Accessory apartment, Zoning Ordinance (Chapter 290) - town PDF, p. 7
    The accessory apartment shall comply with all applicable building codes and is subject to the State of Maine's Subsurface Waste Water Rules, as may be amended, 1as well as the minimum lot size requirements for lots in the shoreland zone.
  8. §290-8.5B(3), Coastal Residential District permitted uses, Zoning Ordinance (Chapter 290) - town PDF, p. 58
    (d) Accessory apartment.[Added7-14-2020]
  9. §290-5.2, Permits required, Zoning Ordinance (Chapter 290) - town PDF, p. 27
    None of the following actions shall be taken until the Code Enforcement Officer has issued a building and/or use permit certifying that the plans of an intended use of the land or building are in conformity with this chapter.
  10. §290-8.6E(2), Village Extension space and bulk standards (Sewer / No Sewer columns), Zoning Ordinance (Chapter 290) - town PDF, p. 63
    Accessory apartments No increase in lot area required (see 20,000 square feet definition)
This page summarizes Camden'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 Planning, Development and Code Enforcement Department (207-236-3353 ext. 7112 (dept); CEO ext. 7114) before you build. Spot an error?