York County · Maine
ADU rules in South Berwick, ME
South Berwick is a York County town on the Salmon Falls River.
South Berwick is in our service area. This page covers what the town ordinance says about ADUs.
Town ADU rules
What’s allowed on your lot in South Berwick.
South Berwick allows an ADU with an existing single-family house under §140-46.1, amended December 12, 2023.
- Size limit
- 190 sq ft min; 750 sq ft max living area
- Where it can go
- Within, attached to, or stand-alone next to an existing single-family home
- Owner on site
- Owner must live in the house or the ADU
- Parking
- No additional spaces required
- Approval
- Code Enforcement Officer approval
- Water setback
- 100 ft in the Shoreland and Slope District; 250 ft for Resource Protection waters and features; accessory structures 100 ft from the normal high-water elevation
Allowed
- ApprovalThe Code Enforcement Officer approves adding one dwelling unit to an existing single-family dwelling. ADU is 'Y' (permitted) in every district in Table A.§ 140-46.1; Table A
- Attached or detachedADU may be within the existing building, attached to it, or stand-alone, provided all dimensional standards of the zone can be met.§ 140-46.1A
- SizeADU may not exceed 750 sq ft of living area; the definition sets a minimum of 190 sq ft.§ 140-9 (definition); § 140-46.1A
- Owner on siteEither the principal or accessory unit must be owner-occupied by a person with a possessory interest who bears the economic risk and receives any rent from the other unit.§ 140-46.1B
- LotTable B dimensional standards must be met. On a nonconforming lot an ADU is allowed if it does not further increase the nonconformity. An ADU built without Town approval must still be allowed if it meets the code.§ 140-46.1C, G, H
- LotDevelopment must meet the two-unit shoreline frontage requirement of § 140-46A(2) (for 2 units: 400 ft shore frontage in R1-R5, B2; 200 ft in B1 and BR).§ 140-46.1D; § 140-46A(2)
- SepticMust meet the Maine State Plumbing Code and show adequate water supply. A house on on-site wastewater may not be modified until a licensed site evaluator shows a new system can be installed or the existing one has capacity.§ 140-46.1E
- ParkingNo additional parking spaces required for the ADU.§ 140-46.1F
- OtherIn Shoreland Zone areas, shoreland zoning standards apply to the ADU.§ 140-46.1I
- ShorelandChapter 110 Shoreland Zoning (adopted 8-31-2010). Structures set back 250 ft from the normal high-water line of Great Ponds Act ponds and rivers flowing to them (except the Great Works River in R1/R2), 250 ft from Resource Protection water bodies and features in § 110-18A (100 ft for permitted uses in RP), and 100 ft in the Shoreland and Slope District (§ 110-18B). 25 ft from minor freshwater wetlands and river banks. Max lot coverage in shoreland 20% (residential districts), 60%-70% in industrial. If more than one dwelling unit is on a parcel, all dimensional requirements must be met for each additional unit (Table C note 9). Chapter 140 § 140-54 also puts accessory structures 100 ft from the normal high-water elevation.§ 110-31A-B; Table C and notes; § 140-54
Not allowed
- Not allowedMore than one ADU; ADU only with an existing single-family dwelling.§ 140-46.1
- Not allowedADU over 750 sq ft of living area.§ 140-46.1A; § 140-9
- Not allowedNeither unit owner-occupied.§ 140-46.1B
Read 2026-11-15 from Town of South Berwick Code, Chapter 140 Zoning (§ 140-46.1 Accessory dwelling units; Table A Land Use; Table B Dimensional Requirements) and Chapter 110 Shoreland Zoning (Table C) (§ 140-46.1 [Amended 12-12-2023]; Table A amended through 12-12-2023; Table B amended 4-13-2009; 5-11-2009; 5-23-2023; 12-12-2023 (Supp 23, Dec 2023); Chapter 110 adopted 8-31-2010, Table C dated 02-01-2011. ecode360 code version 2026-04-28. Read live 2026-11-15.). Anything not listed here, we check with the South Berwick land-use office for your lot.
Setbacks
Front, side and rear in South Berwick.
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
South Berwick's dimensional table, as printed in the ordinance.
| District | Front | Side | Rear | Lot / cover / height |
|---|---|---|---|---|
| R1primaryVillage Residential§ 140-19, Table B (Amended 4-13-2009; 5-11-2009; 5-23-2023; 12-12-2023); Table A. R1 frontage 100 ft. R1 accessory buildings: not in a required front yard; at least 10 ft from side or rear lot lines when to the rear of the main building (§ 140-54). | 20 ft | 15 ft | 15 ft | 40,000 sq ft per unit without sewer; 10,000 sq ft with sewer · 30% (lot coverage = buildings, parking areas, roadways, sidewalks and driveways) · Height 35 ft |
| R1AVillage Residential Growth§ 140-19, Table B (Amended 4-13-2009; 5-11-2009; 5-23-2023; 12-12-2023); Table A. R1A frontage 200 ft without sewer; 125 ft with sewer. R1A accessory buildings: not in a required front yard; at least 10 ft from side or rear lot lines when to the rear of the main building (§ 140-54). | 50 ft (on sewer: 20 ft) | 25 ft (on sewer: 15 ft) | 25 ft (on sewer: 20 ft) | 80,000 sq ft per unit without sewer; 20,000 sq ft with sewer · 30% (lot coverage = buildings, parking areas, roadways, sidewalks and driveways) · Height 35 ft |
| R2Developing Residential§ 140-19, Table B (Amended 4-13-2009; 5-11-2009; 5-23-2023; 12-12-2023); Table A. R2 frontage 125 ft. R2 accessory buildings: not in a required front yard; at least 10 ft from side or rear lot lines when to the rear of the main building (§ 140-54). | 25 ft | 25 ft | 25 ft | 40,000 sq ft per unit without sewer; 30,000 sq ft with sewer · 25% (lot coverage = buildings, parking areas, roadways, sidewalks and driveways) · Height 35 ft |
| R2ASuburban Growth§ 140-19, Table B (Amended 4-13-2009; 5-11-2009; 5-23-2023; 12-12-2023); Table A. R2A frontage 200 ft without sewer; 150 ft with sewer. R2A accessory buildings: not in a required front yard; at least 10 ft from side or rear lot lines when to the rear of the main building (§ 140-54). | 50 ft (on sewer: 25 ft) | 25 ft (on sewer: 20 ft) | 25 ft (on sewer: 20 ft) | 80,000 sq ft per unit without sewer; 40,000 sq ft with sewer · 25% (lot coverage = buildings, parking areas, roadways, sidewalks and driveways) · Height 35 ft |
| R3Transitional Residential§ 140-19, Table B (Amended 4-13-2009; 5-11-2009; 5-23-2023; 12-12-2023); Table A. R3 frontage 200 ft. R3 accessory buildings: not in a required front yard; at least 10 ft from side or rear lot lines when to the rear of the main building (§ 140-54). | 50 ft | 25 ft | 25 ft | 80,000 sq ft per unit without sewer; 80,000 sq ft with sewer · 20% (lot coverage = buildings, parking areas, roadways, sidewalks and driveways) · Height 35 ft |
| R4Rural Residential§ 140-19, Table B (Amended 4-13-2009; 5-11-2009; 5-23-2023; 12-12-2023); Table A. R4 frontage 300 ft. R4 accessory buildings: not in a required front yard; at least 10 ft from side or rear lot lines when to the rear of the main building (§ 140-54). | 50 ft | 50 ft | 50 ft | 120,000 sq ft per unit without sewer; 120,000 sq ft with sewer · 20% (lot coverage = buildings, parking areas, roadways, sidewalks and driveways) · Height 35 ft |
| R5Agamenticus Resource§ 140-19, Table B (Amended 4-13-2009; 5-11-2009; 5-23-2023; 12-12-2023); Table A. R5 frontage 300 ft. R5 accessory buildings: not in a required front yard; at least 10 ft from side or rear lot lines when to the rear of the main building (§ 140-54). | 50 ft | 50 ft | 50 ft | 120,000 sq ft per unit without sewer; 120,000 sq ft with sewer · 15% (lot coverage = buildings, parking areas, roadways, sidewalks and driveways) · Height 35 ft |
| B2Business and Service§ 140-19, Table B (Amended 4-13-2009; 5-11-2009; 5-23-2023; 12-12-2023); Table A. B2 frontage 100 ft. B2 accessory buildings: not in a required front yard; at least 10 ft from side or rear lot lines when to the rear of the main building (§ 140-54). | 20 ft | 15 ft | 15 ft | 40,000 sq ft per unit without sewer; 10,000 sq ft with sewer · 50% (lot coverage = buildings, parking areas, roadways, sidewalks and driveways) · Height 35 ft |
| B1Central Commercial§ 140-19, Table B (Amended 4-13-2009; 5-11-2009; 5-23-2023; 12-12-2023) note (3); Table A. B1 frontage NA. B1 accessory buildings: § 140-54 applies. | NA | NA | NA | NA (no dimensional requirements except height, Table B note 3) · NA · Height 35 ft (same as B2) |
| BRBusiness Residential§ 140-19, Table B (Amended 4-13-2009; 5-11-2009; 5-23-2023; 12-12-2023); Table A. BR frontage 70 ft with sewer (NA without); maximum street frontage 150 ft. BR accessory buildings: § 140-54. | 20 ft (see § 140-24D) | 10 ft | 15 ft | Single-family 10,000 sq ft · 60% (lot coverage = buildings, parking areas, roadways, sidewalks and driveways) · Height 35 ft |
| I2Industrial (I and I2 column)§ 140-19, Table B (Amended 4-13-2009; 5-11-2009; 5-23-2023; 12-12-2023); Table A. I2 frontage 200 ft. I2 accessory buildings: § 140-54. | 40 ft | 35 ft | 35 ft | 80,000 sq ft with or without sewer · 60% (lot coverage = buildings, parking areas, roadways, sidewalks and driveways) · Height 35 ft (Board may allow industrial structures up to 55 ft) |
| SPShoreland and Slope District (shoreland)Chapter 110 Table C; Chapter 140 Table A. SP frontage Shore frontage: tidal 150-200 ft, nontidal 200 ft (one unit); 400 ft for 2 units. SP accessory buildings: 100 ft from the water. | underlying district (Table B) | underlying district (Table B) | underlying district (Table B) | Table C: tidal 30,000-40,000 sq ft (40,000 on septic), nontidal 40,000 sq ft · 20% in R districts (Table C, 'as defined') · Height 35 ft (§ 110-31B(3)) |
Verified 2026-11-15 against Town of South Berwick Code, Chapter 140 Zoning (§ 140-46.1 Accessory dwelling units; Table A Land Use; Table B Dimensional Requirements) and Chapter 110 Shoreland Zoning (Table C). Towns amend ordinances, so confirm with the land-use office before you build. Official source
FAQ
ADUs in South Berwick.
- How big can an ADU be in South Berwick?
- 190 sq ft min; 750 sq ft max living area, per § 140-9 (definition); § 140-46.1A as read 2026-11-15.
- Does the owner have to live on the lot in South Berwick?
- Owner must live in the house or the ADU (§ 140-46.1B).
- Can an ADU in South Berwick be detached?
- Within, attached to, or stand-alone next to an existing single-family home, under § 140-46.1A.
Planning an ADU in South Berwick?
Call (978) 987-0089 and we will read the ordinance against your lot. See the ADU models