Bolthole Index

Plymouth County, Massachusetts

Zoning, building permits and septic rules in Plympton, Massachusetts

The Town of Plympton, Massachusetts requires a building permit for a home, and the town's own Building Department issues it1. Plympton writes and enforces its own zoning bylaw2. Septic approval comes from the Plympton Board of Health, not the county3.

At a glance

Building permit
Required; issued by the Plympton Building Department14
Zoning
Town bylaw with agricultural-residential, business, light manufacturing and industrial districts5
Minimum lot (AR district)
60,000 sq ft with 200 ft of frontage6
Septic
Plympton Board of Health under state Title 537
RV or trailer as a dwelling
Limited to 60 days without a Zoning Board of Appeals special permit8
Accessory dwelling unit
Allowed with limits; building permit required9
Owner-builder
Owner-occupants appear able to pull their own permit10

Who to call

Building permits

Plympton Building Department

Building permits, inspections and certificates of occupancy, plus zoning determinations and zoning enforcement inside Plympton

(781) 585-0571

buildingadmin@plymptontown.org

Town House 5 Palmer Road Plympton MA 02367

Septic permits

Plympton Board of Health

Title 5 septic permits, septic installer and Title 5 inspector permits, well permits and percolation tests inside Plympton

781-585-7000

boh@plymptontown.org

5 Palmer Road

Contact details are copied from each office’s official page and were checked against it on October 23, 2026.

Off-grid gear

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

These are affiliate links — we may earn a commission, at no cost to you. As an Amazon Associate, Bolthole Index earns from qualifying purchases.

Do you need a building permit in Plympton, Massachusetts?

Yes. The Town of Plympton requires a building permit, because Massachusetts enforces its statewide building code through each town's own inspector and Plymouth County has no building department of its own1. The Plympton Building Department issues building permits and certificates of occupancy4.

An accessory dwelling unit needs its own building permit before construction starts11. In the business, light manufacturing and industrial districts, Planning Board site plan approval comes before a building permit, though single-family and two-family dwellings, farm buildings and their accessory buildings are excepted12.

Plympton's fee schedule, the town's own building-code chapter and its inspection rules are still unconfirmed; the Building Department can give current fees and forms.

Who issues building permits in Plympton, and how do you reach them?

The Plympton Building Department at Town House, 5 Palmer Road, handles building permits, inspections and zoning determinations4. Call (781) 585-0571 or email buildingadmin@plymptontown.org4. The office is open Monday through Thursday, 9 am to 2 pm4.

The Building Department also handles zoning enforcement, so a call there is the quickest way to learn whether a planned shed, barn or addition fits the bylaw4. Plympton is a town with its own offices; the county commissioners in Plymouth do not issue building permits, zoning approvals or septic permits13.

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

Plympton has its own zoning bylaw, Chapter 300 of the town code, with agricultural-residential (AR), business, light manufacturing and industrial districts25. AR is the main residential district. Overlay districts for floodplain and watershed, historic, groundwater protection and residential development sit on top of the base districts5.

In AR, a lot needs at least 60,000 sq ft and 200 ft of frontage on a town-maintained public way or an approved subdivision way6. Retreat lots need 120,000 sq ft6. Buildings may cover no more than 30% of an AR lot14, impervious surface is capped at 60%15, and buildings are limited to 35 ft16.

A minimum floor area for a house inside Plympton was not found in the bylaw sections we reviewed. Massachusetts zoning bylaws cannot regulate the interior area of a single-family home in any case17.

How do septic permits work in Plympton?

The Plympton Board of Health handles septic. The board enforces the state Title 5 septic regulations along with Plympton's own supplemental Title 5 rules, issues permits for septic installations and repairs, and its Health Agent witnesses percolation tests18. Septic permits in Plympton come from the town, not Plymouth County19.

Soil matters here. Only about 2.6% of Plymouth County soils rate "not limited" for a conventional drain field20, so expect a percolation test and possibly an engineered system. Private wells carry a separate step: the state certifies well drillers, and a town can require its own site permit21. Plympton's Board of Health also issues well installation permits18.

Can you live in an RV, trailer or tiny home in Plympton?

Only briefly without special approval. Plympton's bylaw bars a trailer or mobile home on private property from serving as a dwelling for more than 60 days unless the Zoning Board of Appeals grants a special permit8. Board of Health approval of sewage disposal and drinking water is required before a temporary dwelling is occupied22. Commercial trailer coach parks are prohibited23.

A family whose home burned can place a manufactured home on the site for up to 12 months during rebuilding24.

Tiny homes: we found no Plympton rule written for them. The state's tiny-house law applies only in designated seasonal communities25. Ask the Building Department before buying land for one.

Accessory dwellings are the practical alternative. Plympton allows an ADU of up to 900 sq ft by right, or up to 1,200 sq ft with Planning Board site plan review9. ADUs cannot be rented short term26.

Building a home in Plympton: the steps, in order

  1. Confirm the lot meets the AR minimums and has frontage on an accepted way6. Land splits go through the Planning Board under the town's subdivision regulations27.
  2. Call the Plympton Board of Health about a percolation test and septic design18.
  3. Check floodplain and groundwater protection overlays on the zoning map with the Building Department5.
  4. Apply to the Building Department for a building permit4. Owner-occupants of a one- or two-family home appear able to act as their own contractor10.
  5. Schedule inspections and request a certificate of occupancy4.

What stays with Plymouth County, and what to check before you buy in Plympton

Almost nothing about building rules sits at the county level in Massachusetts. For other towns in the county, see the Plymouth County page.

County-level numbers: Plymouth County's median property tax bill is about $6,345 a year28, at an effective rate of 1.2%29. About 76% of the county is wooded30. Ask the Building Department about the floodplain overlay and the Board of Health about well and septic before you make an offer.

Watch-outs

  • Plympton's fees, building-code chapter, inspection rules, driveway access rules and certificate-of-occupancy process were not confirmed; the Building Department at (781) 585-0571 can answer them4.
  • The 60-day limit on living in a trailer covers any district, and a special permit from the Zoning Board of Appeals is needed to stay longer8.
  • Part of a lot in the floodplain overlay counts only partly toward the AR lot minimum, and at least 40% of the minimum lot must be upland6.
  • A Plympton ADU cannot be leased for less than one calendar year, and the owner must live in the main house or the ADU9.

Sources

  1. Mass.gov — 780 CMR Massachusetts State Building Code (Administration) (2026 county census)
  2. Article V Intensity of Use Regulations, §§ 300-5.0 to 300-5.10 - Town of Plympton, MA (eCode360) (Town of Plympton), quoted and re-checked
  3. Article VI General Regulations, §§ 300-6.1 to 300-6.11 - Town of Plympton, MA (eCode360) (Town of Plympton), quoted and re-checked
  4. Plympton Building Department (town.plympton.ma.us)
  5. Article III Districts, § 300-3.1 Use districts - Town of Plympton, MA (eCode360) (Town of Plympton), quoted and re-checked
  6. Article V Intensity of Use Regulations, §§ 300-5.0 to 300-5.10 - Town of Plympton, MA (eCode360) (Town of Plympton), quoted and re-checked
  7. Mass.gov — 310 CMR 15.000 Septic Systems (Title 5) (2026 county census)
  8. Article VI General Regulations, §§ 300-6.1 to 300-6.11 - Town of Plympton, MA (eCode360) (Town of Plympton), quoted and re-checked
  9. Article V Intensity of Use Regulations, §§ 300-5.0 to 300-5.10 - Town of Plympton, MA (eCode360) (Town of Plympton), quoted and re-checked
  10. Mass.gov — 780 CMR State Building Code (Administration) (2026 county census)
  11. Article V Intensity of Use Regulations, §§ 300-5.0 to 300-5.10 - Town of Plympton, MA (eCode360) (Town of Plympton), quoted and re-checked
  12. Article VI General Regulations, §§ 300-6.1 to 300-6.11 - Town of Plympton, MA (eCode360) (Town of Plympton), quoted and re-checked
  13. General Laws c. 40A, § 1A — Definitions, quoted and re-checked
  14. Article V Intensity of Use Regulations, §§ 300-5.0 to 300-5.10 - Town of Plympton, MA (eCode360) (Town of Plympton), quoted and re-checked
  15. Article V Intensity of Use Regulations, §§ 300-5.0 to 300-5.10 - Town of Plympton, MA (eCode360) (Town of Plympton), quoted and re-checked
  16. Article V Intensity of Use Regulations, §§ 300-5.0 to 300-5.10 - Town of Plympton, MA (eCode360) (Town of Plympton), quoted and re-checked
  17. General Law - Chapter 40A, Section 3 (Massachusetts statewide rule), quoted and re-checked
  18. Plympton Board of Health (town.plympton.ma.us)
  19. Massachusetts General Laws, Chapter 111, Section 31E, quoted and re-checked
  20. 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
  21. Massachusetts General Laws Chapter 21G, Section 20 (Massachusetts statewide rule), quoted and re-checked
  22. Article VI General Regulations, §§ 300-6.1 to 300-6.11 - Town of Plympton, MA (eCode360) (Town of Plympton), quoted and re-checked
  23. Article VI General Regulations, §§ 300-6.1 to 300-6.11 - Town of Plympton, MA (eCode360) (Town of Plympton), quoted and re-checked
  24. Article VI General Regulations, §§ 300-6.1 to 300-6.11 - Town of Plympton, MA (eCode360) (Town of Plympton), quoted and re-checked
  25. Massachusetts General Laws Chapter 23B, Section 32 (Massachusetts statewide rule), quoted and re-checked
  26. Article V Intensity of Use Regulations, §§ 300-5.0 to 300-5.10 - Town of Plympton, MA (eCode360) (Town of Plympton), quoted and re-checked
  27. Town of Plympton, MA Code table of contents (eCode360) (Town of Plympton), quoted and re-checked
  28. Median property tax bill: Bolthole Index county data
  29. Effective property tax rate: Bolthole Index county data
  30. Wooded share of land: Bolthole Index county data

Written October 23, 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 Plympton

Town of Plympton’s own rules

  • Building permitRequired

    Accessory dwelling units inside Plympton town limits

    • Applies to ADU construction only; the general building permit rule in Chapter 120 was not opened.
    “b. no adu shall be constructed without applying for a building permit.”
  • Local zoningPresent (with conditions)

    Land inside Plympton town limits: the Town of Plympton administers its own zoning bylaw (Chapter 300, Zoning) with agricultural-residential, business, light manufacturing and industrial districts.

    • Use and dimensional rules vary by district; see the district-specific claims.
    • Several uses require a special permit from the Zoning Board of Appeals or site plan review by the Planning Board.
    • The bylaw's amendments are dated in the code (for example amended 5-15-2024 and 5-14-2025); the code table of contents states it includes legislation through 05-15-2024.
    “a dwelling hereafter erected in an agricultural-residential district, or in a business district, or in a light manufacturing district, or in an industrial district shall be located on a lot having not less than the minimum requirements set forth in this bylaw.”
  • Zoning districtsPublished

    Land inside Plympton town limits

    • Districts are agricultural-residential (AR), business (B), light manufacturing (LM) and industrial (I); overlay districts (floodplain and watershed, historic, groundwater protection, residential development overlay) are superimposed over them under § 300-3.2.
    • The zoning map is § 300-3.7; this run did not open the map itself.
    “for purposes of this bylaw, the town of plympton is hereby divided into the following types of use districts: agricultural-residential (ar) business (b) light manufacturing (lm) industrial (i)”
  • Minimum lot sizeSpecified

    Lots in the Plympton agricultural-residential (AR) district, the main residential district, inside town limits

    • Minimum area 60,000 sq ft and minimum frontage 200 ft in AR.
    • Two-family dwelling lots in AR require 100,000 sq ft.
    • Retreat lots (§ 300-5.8) require 120,000 sq ft and 40 ft frontage; the bylaw measures frontage on a town-maintained public way or a way on an approved subdivision plan (§ 300-5.2).
    • A lot smaller than the table may qualify only if it was recorded before the bylaw was adopted and did not adjoin other land of the same owner (§ 300-5.1 a.).
    • Part of a lot in the floodplain overlay may count toward lot area, capped at 50% of the AR minimum; at least 40% of the minimum lot must be contiguous upland (§ 300-5.6).

    minimum lot area: >= 60000 sq ft (two-family dwellings 100,000 sq ft; retreat lots 120,000 sq ft) · minimum lot frontage: >= 200 ft (retreat lots 40 ft)

    “area (square feet) 60,000 60,000 60,000 60,000 frontage (feet) 200 200 200 200”
  • Lot coverageSpecified

    Lots in the Plympton agricultural-residential (AR) district inside town limits: maximum impervious coverage

    • Also subject to the groundwater protection district requirements in § 300-8.3.

    maximum impervious coverage: <= 60 percent of lot (also subject to groundwater protection districts, § 300-8.3)

    “e. maximum percentage of impervious coverage of land; also subject to the requirements of groundwater protection districts, § 300-8.3. ar b lm i 60% 60% 60% 60%”
    One more reviewed finding on this topic
  • Building heightSpecified

    Buildings in the Plympton agricultural-residential (AR) district inside town limits

    • Height limits do not apply to chimneys, ventilators, towers, spires or other ornamental features not used for living purposes (§ 300-5.7).

    maximum building height: <= 35 ft · maximum number of stories: <= 2.5 stories

    “number of stories 2 1/2 3 3 3 height in feet 35 35 35 40”
  • Living in an RVLimited

    Trailers set on private property inside Plympton town limits when used as a dwelling

    • The 60-day limit and special-permit rule in § 300-6.3 a. covers trailers as well as mobile homes.
    • Board of Health approval for sewage disposal and potable water is required before a temporary dwelling is occupied (§ 300-6.3 b.).
    • Travel or vacation trailers are defined separately in Article XI (definitions); that definition was not opened in this run.

    maximum days as dwelling without special permit: <= 60 days (Zoning Board of Appeals special permit)

    “a. no mobile home or trailer shall be set upon private property in any district for use as a dwelling, storage, sales or office space for a period of more than 60 days except as authorized by special permit from the board of appeals.”
  • Camping on your landLimited

    Commercial trailer coach parks inside Plympton town limits

    • Applies only to commercial trailer coach parks; private, non-commercial temporary camping is not addressed in the sections read.
    “d. no lot, parcel or tract of land in any district shall be used for the purposes of a commercial trailer coach park.”
  • Manufactured homesLimited

    Mobile homes set on private property in any district inside Plympton town limits

    • A mobile home may not be used as a dwelling, storage, sales or office space for more than 60 days unless the Zoning Board of Appeals grants a special permit (§ 300-6.3 a.).
    • Schedule of uses lists temporary mobile homes as requiring a Zoning Board of Appeals special permit in all four districts (§ 300-4.2).
    • For a temporary dwelling, Board of Health approval for sewage disposal and potable water must be obtained before occupancy (§ 300-6.3 b.).
    • A dwelling destroyed by fire or natural cause may be replaced by a mobile home on the site for up to 12 months during rebuilding (§ 300-6.3 c.).

    maximum days without special permit: <= 60 days (Zoning Board of Appeals special permit; 12 months while a fire- or natural-loss residence is rebuilt)

    “a. no mobile home or trailer shall be set upon private property in any district for use as a dwelling, storage, sales or office space for a period of more than 60 days except as authorized by special permit from the board of appeals.”
  • Accessory dwellingsLimited

    Accessory dwelling units (ADUs) on lots inside Plympton town limits in districts where single-family dwellings are permitted or allowed

    • A by-right ADU may not exceed one-half the gross floor area of the principal dwelling or 900 sq ft, whichever is smaller; an ADU up to 1,200 sq ft needs site plan review by the Planning Board (§ 300-5.10 c.(5)).
    • The lot must meet the minimum lot size for its district, and the ADU may not raise the lot above two dwelling units (§ 300-5.10 c.(6)).
    • The owner must occupy the primary residence or the ADU, and no ADU may be leased for less than one calendar year (§ 300-5.10 c.(9)).
    • One additional parking space is required, unless the lot is within 0.5 miles of a transit station (§ 300-5.10 c.(8)).
    • A building permit must be applied for before an ADU is constructed (§ 300-5.10 b.).
    • The bylaw cites 760 CMR 71.00 for undefined terms; the section was amended 5-14-2025 (art. 20).

    by-right ADU maximum gross floor area: <= 900 sq ft (one-half the principal dwelling gross floor area if smaller) · site plan review ADU maximum gross floor area: <= 1200 sq ft

    “(5) a by-right adu not larger in gross floor area than 1/2 the gross floor area of the principal dwelling or 900 square feet, whichever is smaller”
  • Who permits septicLocal (with conditions)

    Sewage disposal for a temporary dwelling inside Plympton town limits

    • The bylaw ties sewage disposal approval to the town Board of Health for temporary dwellings; the state Title 5 rules (310 CMR 15.00) also apply but were not opened in this run.
    • The bylaw's on-site septic reference in § 300-5.0 indicates lots rely on on-site septic systems.
    “b. for use as a temporary dwelling, board of health approval for sewage disposal and potable water supply must be obtained prior to occupancy.”
  • Septic permitRequired

    Temporary dwellings (including trailers or mobile homes used as dwellings) inside Plympton town limits

    • Board of Health approval must be obtained before occupancy.
    • This bylaw section does not set out the application or permit form for a general residential septic system.
    “b. for use as a temporary dwelling, board of health approval for sewage disposal and potable water supply must be obtained prior to occupancy.”
  • Subdividing landRegulated (with conditions)

    Land divisions inside Plympton town limits under the town's subdivision regulations

    • The town's subdivision regulations are Chapter 350 (§ 350-1.1 to § 350-6.3) of the town code.
    • Frontage must be on a town-maintained public way or a way shown on a subdivision plan approved by the Planning Board under subdivision control statutes (§ 300-5.2).
    • The Chapter 350 text was not opened in this run.
    “chapter 350 subdivision regulations (§ 350-1.1”
  • Short-term rentalsLimited

    Renting rooms in a dwelling in the Plympton agricultural-residential (AR) district inside town limits

    • Renting of rooms is allowed by right in AR with a four-person limit.
    • A bed-and-breakfast establishment, including conversion of an existing dwelling, needs site plan review by the Planning Board in AR.
    • Use in the business and light manufacturing districts follows the same schedule of uses (§ 300-4.2).

    guest limit: <= 4 persons (renting of rooms)

    “renting of rooms (4-person limit) a a a x”
    One more reviewed finding on this topic
  • Permit processPartial

    Nonresidential building permits in the business, light manufacturing and industrial districts inside Plympton town limits

    • Planning Board site plan approval is required before a building permit may be issued in these districts, with the exception of single-family and two-family dwellings, farm buildings and accessory buildings (§ 300-6.7 a.).
    • The rest of the permit procedure (application, fees, timing) was not opened in this run.
    “approval of a site plan by the planning board shall be required before any building permit may be issued, with the exception of single-family and two-family dwellings, farm buildings and accessory buildings to the same.”

Still unanswered

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

  • Owner-builder exemption — Owner-builder permit exemption inside Plympton town limits
  • Building code adopted — Building code adoption inside Plympton town limits
  • Inspections — Building inspections inside Plympton town limits
  • Certificate of occupancy — Certificate of occupancy for new homes inside Plympton town limits
  • Minimum dwelling size — Minimum dwelling floor area inside Plympton town limits
9 more unanswered
  • Tiny homes
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Mandatory utility hookup
  • Agricultural exemption
  • Driveway access
  • Building in a floodplain
  • Permit fees

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 Plympton publishes no rule on the point, not that none exists. Plymouth County’s page lists the county offices to call.

← All of Plymouth County: county rules, score and offices