Bolthole Index

Worcester County, Massachusetts

Zoning, building permits and septic rules in Southborough, Massachusetts

The Town of Southborough, Massachusetts, in Worcester County, administers its own zoning bylaw, Chapter 1741. Building questions go to the town's Building Department on Cordaville Road2, and septic systems are regulated by the Southborough Board of Health under the state Title 5 code3. Worcester County has no functioning county government that issues these permits4.

At a glance

Zoning
Town-run: Chapter 174 Zoning, with districts such as RA Residence A15
Lot size (RA district)
43,560 sq ft minimum, with at least 20,000 sq ft outside wetlands6
RV or mobile home as a dwelling (RA)
By right for 30 days or fewer a year; longer needs a special permit7
Accessory dwelling (RA)
By right up to 900 sq ft or half the main house, whichever is smaller8
Building code
State building code applies to every building in every Massachusetts town9
Septic permits
Southborough Board of Health, under state Title 53
Owner-builder
Owner-occupants of 1- and 2-family homes are exempt from contractor licensing but still need a building permit10

Who to call

Building permits

Southborough Building Department

Building permits and building inspections inside the Town of Southborough

508-485-0717

9 Cordaville Road, Lower Level, Southborough, Massachusetts

Septic permits

Southborough Health Department (Board of Health)

Septic (on-site sewage disposal) permits and Title 5 enforcement inside Southborough

508-481-3013

9 Cordaville Road Cordaville Hall, Lower Level Southborough , MA 01772

Well permits

Southborough Health Department (private wells)

Private well permit application and well-water testing guidance

508-481-3013

9 Cordaville Road Cordaville Hall, Lower Level Southborough , MA 01772

Contact details are copied from each office’s official page and were checked against it on October 24, 2026.

Off-grid gear

Going off-grid in Town of Southborough means bringing your own water and power. The kit we’d start with:

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Does Southborough have zoning, and what does it mean for lot size and setbacks?

Yes. The Town of Southborough adopts and administers its own zoning bylaw, Chapter 174, and use and dimensional rules change by district1. The districts include Conservation, Residence A (RA), Residence B (RB), Business Village, Highway Business, industrial and research districts, a Downtown district and an MBTA communities overlay5.

RA is the main single-family district. In RA, a lot needs 43,560 square feet, with at least 20,000 square feet exclusive of wetlands6. Setbacks in RA are 35 feet front, 50 feet rear and 25 feet side; accessory buildings and swimming pools need 10 feet at the rear and side11. The height limit is 35 feet and 2 1/2 stories, or 17 feet and one story for accessory buildings12.

A separately owned lot that predates the dimensional rules and has not been combined with neighbors can hold a one-family house with at least 5,000 square feet and 50 feet of frontage13. Massachusetts bars local zoning from regulating the interior area of a single-family home, so Southborough cannot set a minimum house size through zoning14.

Can you live in an RV, mobile home or accessory unit in Southborough?

In the RA district, a mobile home or travel trailer used as a dwelling is allowed by right for 30 days or fewer in a year7. Living in one longer than that requires a special permit15. The statewide campground rule covers only state parks and forests and does not answer living in an RV on your own lot16.

A separate accessory dwelling unit in RA is allowed by right up to 900 square feet or half the main house's floor area, whichever is smaller; a larger one needs a special permit8. State law also protects a single accessory dwelling unit in single-family districts, subject to reasonable regulation17.

We could not confirm any Southborough rule on tiny homes, so ask the Building Department before buying a plan or a trailer-based unit2.

Do you need a building permit in Southborough, and who issues it?

The Southborough Building Department, at 9 Cordaville Road in the lower level, is the office to call about building permits and inspections inside the town2. The Massachusetts state building code applies to every building in every city and town, and a local inspector enforces it9.

We could not read Southborough's own building chapter, so the exact permit thresholds, fees and certificate of occupancy steps are unconfirmed; ask the Building Department. Homeowners building their own owner-occupied one- or two-family house are exempt from contractor licensing, but a permit is still required for work that needs one, and a homeowner who hires help must act as supervisor10.

How do septic permits work in Southborough?

Septic permits for Southborough come from the town's own Board of Health and Health Department, which enforces the state Title 5 code3. Massachusetts lets local boards of health administer permits for individual sewage disposal systems while state minimums apply everywhere18. The Board of Health has added its own addenda on septic tanks and percolation rates3.

Soils matter. Only 1.4% of the soils in Worcester County rate as not limited for a conventional drain field, so expect a soil test and often an engineered system19.

If a public sewer runs in the street in front of a parcel, state law requires connection as the sewer authority directs20. We could not confirm Southborough's sewer connection distance, so ask the Health Department.

Private wells: a Massachusetts town may require a local site permit from the driller21, and the Health Department posts a well permit application22.

Building a home in Southborough: the steps, in order

  1. Confirm the district and lot standards in Chapter 174; in RA that means 43,560 square feet and the setbacks above6.
  2. If you are dividing land, submit the plan to the town planning board first, because Massachusetts requires approval before a subdivision23.
  3. Call the Health Department about soil testing and a septic design, or a sewer connection if a sewer is available3.
  4. Ask about a private well permit if the lot has no public water22.
  5. Apply for a building permit and call the Building Department to schedule inspections2.

What stays with Worcester County, and what to check before you buy in Southborough

Worcester County does not run building permits or zoning for Southborough; those are municipal24. The county's own page covers land elsewhere in the county: Worcester County.

Before buying, check the zoning district on the town's map, wetlands on the lot, and the septic or sewer situation. Worcester County's effective property tax rate is 1.3%25, and the typical home value is about $507,04926.

Watch-outs

  • Southborough's building chapter was not available to us, so ask the Building Department about permit thresholds, fees and certificates of occupancy before you plan work2.
  • The RA rules above apply to the Residence A district only; other districts such as RB and the business districts have different standards5.
  • Garbage disposal grinders are banned in Southborough, which matters for any home on a septic system3.
  • A building permit is still required for owner-built homes even though contractor licensing is waived10.

Sources

  1. Chapter 174 Zoning, Article III Use Regulations and Schedule (Town of Southborough, eCode360) (Town of Southborough), quoted and re-checked
  2. Southborough Building Department (southboroughma.gov)
  3. Southborough Health Department (Board of Health) (southboroughma.gov)
  4. City of Worcester - Inspectional Services (2026 county census)
  5. Chapter 174 Zoning, Article III Use Regulations and Schedule (Town of Southborough, eCode360) (Town of Southborough), quoted and re-checked
  6. Chapter 174 Zoning, Article III Use Regulations and Schedule (Town of Southborough, eCode360) (Town of Southborough), quoted and re-checked
  7. Chapter 174 Zoning, Article III Use Regulations and Schedule (Town of Southborough, eCode360) (Town of Southborough), quoted and re-checked
  8. Chapter 174 Zoning, Article III Use Regulations and Schedule (Town of Southborough, eCode360) (Town of Southborough), quoted and re-checked
  9. Massachusetts General Laws, Chapter 143, Section 3A: Enforcement of state building code (Massachusetts statewide rule), quoted and re-checked
  10. Building & Zoning | City of Worcester, quoted and re-checked
  11. Chapter 174 Zoning, Article III Use Regulations and Schedule (Town of Southborough, eCode360) (Town of Southborough), quoted and re-checked
  12. Chapter 174 Zoning, Article III Use Regulations and Schedule (Town of Southborough, eCode360) (Town of Southborough), quoted and re-checked
  13. Chapter 174 Zoning, Article IV Dimensional Regulations (eCode360) (Town of Southborough), quoted and re-checked
  14. General Law - Chapter 40A, Section 3 (Massachusetts statewide rule), quoted and re-checked
  15. Chapter 174 Zoning, Article III Use Regulations and Schedule (Town of Southborough, eCode360) (Town of Southborough), quoted and re-checked
  16. Massachusetts General Laws, Chapter 132A, Section 2D (Massachusetts statewide rule), quoted and re-checked
  17. Massachusetts General Laws Chapter 40A, Section 3 (Massachusetts statewide rule), quoted and re-checked
  18. Massachusetts General Laws Chapter 111, Section 31E (Massachusetts statewide rule), quoted and re-checked
  19. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
  20. Massachusetts General Laws Chapter 83, Section 5 (Massachusetts statewide rule), quoted and re-checked
  21. Massachusetts General Laws Chapter 21G, Section 20 (Massachusetts statewide rule), quoted and re-checked
  22. Southborough Health Department (private wells) (southboroughma.gov)
  23. Massachusetts General Laws c. 41, § 81O (Massachusetts statewide rule), quoted and re-checked
  24. City of Worcester - Building & Zoning (2026 county census)
  25. Effective property tax rate: Bolthole Index county data
  26. Typical home value (Zillow): Bolthole Index county data

Written October 24, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.

Answers from the rulebook for Town of Southborough

Town of Southborough’s own rules

  • Local zoningPresent (with conditions)

    Land inside Southborough town limits; the town administers its own zoning bylaw (Chapter 174 Zoning) for use and dimensional rules.

    • Uses and dimensions are governed by district; the RA Residence A district is the main single-family district read in this research.
    • Permitted uses in each district are subject to the Schedule of Use Regulations and special-permit requirements.
    “chapter 174 zoning (§ 174-1 – § 174-28)”
  • Zoning districtsPublished (with conditions)

    Zoning districts of Southborough town (Chapter 174)

    • Districts listed include C Conservation, RA Residence A, RB Residence B, BV Business Village, BH Highway Business, IP, ID, SP, WFP, CR, WCS, Downtown and MCOD.
    “§ 174-8 schedule of use regulations. § 174-8.1 c conservation district. § 174-8.2 ra residence a district. § 174-8.3 rb residence b district. § 174-8.4 bv business village district. § 174-8.5 bh highway business district. § 174-8.6 ip industrial park district. § 174-8.7 id industrial district. § 174-8.8 sp research, scientific and professional district. § 174-8.9 wfp wetland and floodplain district. § 174-8.10 cr critical resource district. § 174-8.11 wcs wireless communication service district. § 174-8.12 downtown district. § 174-8.13 mcod mbta communities overlay district.”
  • Minimum lot sizeSpecified

    Lots in the RA Residence A district (main single-family district) of Southborough town

    • Minimum 20,000 square feet must be exclusive of wetlands.
    • RA is the main single-family district; no agricultural or rural-residential district was identified in the code index.
    • Previously recorded lots are governed by a separate rule (see second claim).

    minimum lot area: >= 43560 sq ft (minimum 20,000 sq ft exclusive of wetlands)

    “d. development standards are as follows: (1) minimum lot area: 43,560 square feet; minimum 20,000 square feet exclusive of wetlands.”
    One more reviewed finding on this topic
    • Specified — Separately owned lots that existed when the dimensional requirements were adopted and have not been since combined, for a one-family house in Southborough town
      “a. any lot which was in ownership separate from adjoining land at the time the dimensional requirements of this chapter were adopted and has not been since consolidated, altered or combined with other lots may be built upon for a one-family residence, provided that such a lot has at least 5,000 square feet in area and 50 feet in frontage.”
  • SetbacksSpecified

    Structures on lots in the RA Residence A district of Southborough town

    • Front 35 ft; rear 50 ft (10 ft for accessory buildings and swimming pools); side 25 ft (10 ft for accessory buildings and swimming pools); other street 35 ft; minimum frontage 150 ft.

    front setback: >= 35 ft · rear setback: >= 50 ft (10 ft for accessory buildings and swimming pools) · side setback: >= 25 ft (10 ft for accessory buildings and swimming pools)

    “(3) minimum setbacks: (a) front: 35 feet. (b) rear: 50 feet; 10 feet for accessory buildings and swimming pools. (c) side: 25 feet; 10 feet for accessory buildings and swimming pools. (d) other street: 35 feet.”
  • Building heightSpecified

    Buildings in the RA Residence A district of Southborough town

    • Accessory buildings limited to 17 feet, one story.
    • Height limitation does not apply to antennas, chimneys, and similar features per the chapter's height exception.

    maximum height: <= 35 ft (2 1/2 stories; accessory buildings 17 ft, one story)

    “(4) maximum height: 35 feet, 2 1/2 stories (17 feet, one story for accessory buildings).”
  • Living in an RVLimited

    Use of a mobile home or travel trailer as a dwelling in the RA Residence A district of Southborough town

    • Permitted by right only for 30 days or fewer in a year.
    • Use for more than 30 days in a year requires a special permit under the RA district special-permit list (item 7).
    • Definition of 'trailer' excludes use as a dwelling in a permanent location.

    use duration by right: <= 30 days per year (RA district only)

    “(7) mobile home or travel trailer used as a dwelling for 30 days or fewer in a year.”
  • Manufactured homesLimited

    Use of a mobile home as a dwelling in the RA Residence A district of Southborough town

    • Permitted by right only for 30 days or fewer in a year.
    • Special permit required for use as a dwelling for more than 30 days in a year.
    • Mobile home is defined in Chapter 174 §174-2 as a structure built on a permanent chassis with wheels, designed to be used as a dwelling when connected to the required utilities.

    use duration by right: <= 30 days per year (RA district only)

    “(7) mobile home or travel trailer used as a dwelling for more than 30 days in a year.”
  • Accessory dwellingsLimited

    Accessory dwelling units on lots in the RA Residence A district of Southborough town

    • Permitted by right only if gross floor area is not larger than one-half the principal dwelling's gross floor area or 900 sq. ft., whichever is smaller.
    • An accessory dwelling unit with gross floor area greater than 900 sq. ft. requires a special permit.

    ADU gross floor area by right: <= 900 sq ft (or one-half the principal dwelling gross floor area, whichever is smaller)

    “(11) accessory dwelling unit that is not larger in gross floor area than ½ the gross floor area of the principal dwelling or 900 sq. ft., whichever is smaller.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Town of Southborough or Worcester County directly.

  • Building permit — New residential construction inside Southborough town
  • Owner-builder exemption — Owner-builder construction inside Southborough town
  • Building code adopted — New residential construction inside Southborough town
  • Inspections — Building inspections inside Southborough town
  • Certificate of occupancy — Certificates of occupancy inside Southborough town
12 more unanswered
  • Minimum dwelling size
  • Lot coverage
  • Camping on your land
  • Tiny homes
  • Off-grid sanitation
  • Well permit
  • Mandatory utility hookup
  • Agricultural exemption
  • Driveway access
  • Short-term rentals
  • Permit fees
  • Permit process

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Unanswered questions are usually a sign that Town of Southborough publishes no rule on the point, not that none exists. Worcester County’s page lists the county offices to call.

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