Dukes County, MA Building Permits, Zoning & Septic Rules

A building permit is required in Dukes County, Massachusetts, but there is no single county building department: the building inspector for the parcel's town enforces the statewide code¹. Each town also administers zoning, while the Martha's Vineyard Commission adds regional review for certain projects²³. Septic systems follow Title 5 and go through the local Board of Health⁴.

At a glance

Building permit: Required under the statewide building code and issued by the parcel's town¹
Zoning: Administered by each town, with added regional review by the Martha's Vineyard Commission for qualifying projects²
Septic permit: Governed by statewide Title 5 and reviewed by the local town Board of Health⁴
Owner-builder: A homeowner may use the license exemption for an owner-occupied one- or two-family dwelling⁵
Tiny house: A seasonal-community town must adopt a bylaw allowing a year-round tiny house of 400 square feet or less⁶
Minimum home size: Local zoning cannot regulate the interior area of a single-family home, though building-code rules still apply⁷
Accessory dwelling unit: One ADU is protected in a single-family residential district, subject to reasonable local rules⁸

Who to call

Planning & zoning

Martha's Vineyard Commission

Regional planning assistance, Developments of Regional Impact and Districts of Critical Planning Concern; town offices still issue local permits

508-693-3453

The Stone Building, 33 New York Avenue, Oak Bluffs, MA 02557

Contact details are copied from each office’s official page and were checked against it on September 28, 2026.

Do you need a building permit in Dukes County, Massachusetts?

Yes. Construction in Dukes County requires a building permit under the Massachusetts State Building Code, with the building inspector for the parcel's town enforcing the requirement rather than a county building department¹. Start with the town where the land lies, because a permit from another island town does not apply to the parcel. A homeowner of an owner-occupied one- or two-family dwelling may qualify to obtain the permit without a construction supervisor's license by filing the homeowner exemption affidavit, but the exemption does not remove the permit requirement⁵. Certain projects can also face regional review after referral by a town permitting agency, so a local approval path may include the Martha's Vineyard Commission³.

Who issues Dukes County building permits, and how do you reach the right office?

Dukes County does not provide one building-permit counter for the entire county; the municipal building inspector for the parcel's town issues and enforces the building permit¹. The same town-first approach applies to zoning and septic review, so identify the municipality from the deed or assessor record before seeking forms²⁴. For regional land-use questions, the Martha's Vineyard Commission provides technical assistance to the seven Dukes County towns and can be reached at The Stone Building, 33 New York Avenue, Oak Bluffs, MA 02557, or 508-693-3453³. The commission is not a substitute for the town building office: qualifying projects are generally referred to it by a town permitting agency³.

Does Dukes County have zoning?

Yes, but zoning is administered town by town, and the Martha's Vineyard Commission adds a regional land-use layer through review of Developments of Regional Impact and Districts of Critical Planning Concern². Parcel-specific uses, lot size, setbacks, height and coverage therefore need to be confirmed in the applicable town's current zoning bylaw; a rule from a neighboring town is not an answer for the parcel. Massachusetts supplies several statewide boundaries: local zoning cannot regulate the interior area of a single-family residential building, although building-code requirements remain⁷. State law also protects one accessory dwelling unit in a single-family residential district, subject to reasonable rules such as site-plan review, setbacks, bulk and height limits⁸. Large or regionally significant proposals may be referred by the town permitting agency to the Martha's Vineyard Commission³.

How do septic permits work in Dukes County?

Dukes County septic systems are governed by Massachusetts Title 5, and the local Board of Health for the parcel's town reviews designs and issues septic permits⁴. Site feasibility deserves attention before a house plan is finalized: zero percent of the county's mapped soils are rated without severe limitations for a conventional septic drain field, so a parcel-specific evaluation may point to an engineered design rather than a basic conventional field⁹. A public sewer changes the path as well; when a town has provided both a drain and a sewer in a public way, an abutting or connected parcel must route sewage to the sewer as directed by the responsible authority¹⁰. Ask the town Board of Health to confirm the required testing, design, permit and inspection sequence for the specific lot before closing or designing the home.

Can you live in an RV or tiny home on your land in Dukes County?

Dukes County has no single confirmed countywide answer for living in an RV on private land; ask the parcel's town zoning or building office about occupancy, temporary camping and utility connections before moving an RV onto the site². Tiny houses have a defined state pathway for seasonal communities, but the municipality must adopt a bylaw permitting them⁶. Under that pathway, a tiny house contains no more than 400 square feet excluding lofts, must meet state and local building requirements, and must serve as year-round housing rather than a seasonal home or a short-term rental⁶. Year-round housing means principal-residence occupancy for at least 10 months each year, and a movable tiny house must be registered when applicable⁶. Confirm that the specific town has adopted the necessary bylaw and that the parcel's zoning district allows the proposal.

Building a home in Dukes County: the steps, in order

Identify the parcel's town, because municipal offices administer building permits, zoning and septic review¹²⁴.
Ask the town zoning office for the parcel's district, allowed use, setbacks, lot requirements and any overlay rules².
Take the site to the town Board of Health for the Title 5 septic process; countywide soil mapping shows zero percent of soils without severe conventional drain-field limitations⁴⁹.
Ask whether the proposal requires Martha's Vineyard Commission review, since town permitting agencies refer qualifying regional projects³.
Apply to the town building inspector under the statewide building code¹.
If acting as the owner-builder of an eligible owner-occupied home, file the homeowner exemption affidavit with the permit materials⁵.
Schedule the town's required inspections and obtain final approval before occupancy¹.

What should you check before buying land in Dukes County?

Confirm the municipality first, then obtain the town zoning map and bylaw, because Dukes County land-use controls are administered locally and can differ across town lines². Make septic feasibility a contract contingency: zero percent of mapped county soils are rated without severe limitations for a conventional drain field, despite 89.5% of county land having a slope of 15% or less⁹¹¹. Ask the town about private-well approval, floodplain development, legal road access and driveway requirements because countywide answers for those topics could not be confirmed. Budget with the island market in mind: the typical home value is about $1,559,624, the typical annual home-insurance premium is about $7,760, and the median annual property-tax bill is about $5,503¹²¹³¹⁴. The effective property-tax rate is about 0.5%¹⁵.

Watch-outs

A Dukes County address does not identify the permitting office; building, zoning and septic applications go to the parcel's town¹²⁴.
Conventional septic conditions are difficult countywide: zero percent of mapped soils are rated without severe drain-field limitations, so secure a parcel-level evaluation early⁹.
RV occupancy, temporary camping, private-well permits and driveway rules could not be confirmed countywide; ask the parcel's town zoning, building, health and road offices before relying on the land for those uses².
A seasonal-community designation alone does not authorize a tiny house; the town must adopt a permitting bylaw and the home must satisfy year-round occupancy and code conditions⁶.

Sources

Written September 28, 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.

How Dukes County scores

Seclusion39100% ev.

Self-Sufficiency59100% ev.

Admin Boringness43100% ev.

Durability81100% ev.

Property Autonomy44100% ev.

Carry Cost48100% ev.

Evidence strength: 100%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$1560kTypical home

0.5%Property tax

$8,824Land / acre

47.1"Annual rain

4% of yrsSevere drought

0 / yr (+0)Mid-century 100°F days

10.7 daysMid-century dry spell

1.97" (+8.9%)Mid-century 1-day rain

1.27×Wildfire change factor

100%Forward climate coverage

$7,760Home insurance / yr

0.5% / yrInsurance growth

0.75%Nonrenewal rate

county median (2+ published ZIPs)Insurance basis

12,242People within 30 min

59,044Radius comparison (15 mi)

201.7People / sq mi

0.9%Federal land

89.5%Land at 15% slope or less

0%Septic soil without severe limits

0 acWorkable land screen

43.7%Wooded land

25 tonsBiomass / forest ac

51.4°FAvg temp

Answers from the rulebook for Dukes County

What the ordinances and state agencies actually say — one answer per question, each quoted from the official source and independently re-checked.

Dukes County rules

Building permitRequired
Under the statewide Massachusetts State Building Code (780 CMR), a building permit is required for all construction (e.g., Edgartown requires one except as exempted by 780 CMR 105.2), enforced by each town's municipal building inspector, not the county.
Town of Edgartown (Dukes County) - Building Inspector ↗Scouted from the county site, not yet independently re-checked
County-wide zoningPresent
Zoning is administered by the towns, and Martha's Vineyard additionally has the Martha's Vineyard Commission, the regional land-use authority reviewing Developments of Regional Impact (DRI) and Districts of Critical Planning Concern (DCPC) for the towns of Dukes County.
Martha's Vineyard Commission - What We Do ↗Scouted from the county site, not yet independently re-checked
Who permits septicMassDEP Title 5 (310 CMR 15.000), enforced by the local Board of Health
Septic systems are governed by the statewide Title 5 / State Environmental Code (310 CMR 15.000) promulgated by MassDEP; the local town Board of Health reviews designs and issues septic permits.
Mass.gov - Septic Systems & Title 5 (MassDEP) ↗Scouted from the county site, not yet independently re-checked
Owner-builder exemptionAvailable
A homeowner of an owner-occupied one- or two-family dwelling may obtain a building permit without a construction supervisor's license under the 780 CMR homeowner license exemption (filing a Homeowner Exemption Affidavit).
Mass.gov - When is a Construction Supervisor License Required (homeowner exemption) ↗Scouted from the county site, not yet independently re-checked

Massachusetts rules that apply here

Zoning districtsPartial
Massachusetts zoning districts, including the statutory requirement applicable to MBTA communities and locally adopted zoning districts.
- Zoning ordinances and bylaws are adopted by cities and towns; the statewide statute does not provide one uniform zoning map or complete statewide district inventory.
- For an MBTA community, at least one reasonable-size district must permit multifamily housing as of right, without age restrictions and suitable for families with children.
- The required MBTA-community district must have a minimum gross density of 15 units per acre, subject to limitations under chapter 131 section 40 and Title 5 of the state environmental code, and must be within 0.5 miles of a commuter rail station, subway station, ferry terminal, or bus station, if applicable.
- Local zoning amendments generally require public hearings and a two-thirds vote, subject to statutory exceptions.
minimum gross density: >= 15 units per acre (Subject to further limitations imposed by section 40 of chapter 131 and Title 5 of the state environmental code.) · maximum distance from applicable transit: <= 0.5 miles (Applies to the MBTA-community district when a qualifying commuter rail station, subway station, ferry terminal, or bus station is applicable.)
“An MBTA community shall have a zoning ordinance or by-law that provides for at least 1 district of reasonable size in which multi-family housing is permitted as of right; provided, however, that such multi-family housing shall be without age restrictions and shall be suitable for families with children.”
General Law, Chapter 40A, Section 3A ↗Re-checked Sep 11, 2026
Minimum dwelling sizeNone
Local zoning ordinances and bylaws statewide, as to the interior area of a single-family residential building.
- This finding concerns zoning regulation; state building-code requirements are not eliminated.
- The cited statute separately permits reasonable bulk and height, yard-size, lot-area, setback, open-space, parking, and building-coverage regulations for land or structures used for specified religious or educational purposes.
“No zoning ordinance or by-law shall regulate or restrict the interior area of a single family residential building”
General Law - Chapter 40A, Section 3 ↗Re-checked Sep 11, 2026
Tiny homesLimited
Tiny-house dwelling occupancy in municipalities designated as Massachusetts seasonal communities.
- A tiny house must be a detached structure containing a dwelling unit of 400 square feet or less, excluding lofts.
- The seasonal community must adopt bylaws or zoning ordinances permitting construction of tiny houses.
- Tiny houses must be designated for year-round housing and meet all state and local building-code requirements.
- Any qualifying undersized-lot housing may not be used as a seasonal home or short-term rental of less than 6 months and must be used as year-round housing.
- A movable tiny house must be registered with the Registry of Motor Vehicles, as applicable.
- The municipality must be in a designated seasonal community; the statute requires designation for municipalities in Dukes and Nantucket counties and specified municipalities in Barnstable and Berkshire counties, and permits additional designations.
maximum floor area: <= 400 square feet excluding lofts · minimum year-round occupancy period: >= 10 months per year (The statute defines year-round housing as principal-residence occupancy for not less than 10 months a year.)
“A seasonal community shall: [...] adopt by-laws to permit the construction of tiny houses provided that such tiny houses are designated for use as year-round housing units”
Massachusetts General Laws Chapter 23B, Section 32 ↗Re-checked Sep 11, 2026
Manufactured homesLimited
Placement and occupancy of a manufactured home on the site of a Massachusetts residence destroyed by fire or another natural holocaust while the residence is being rebuilt.
- The person must be the owner and occupier of the destroyed residence.
- The manufactured home must be placed on the site of that residence.
- Occupancy may not exceed 12 months while the residence is being rebuilt.
- The manufactured home remains subject to the Massachusetts state sanitary code.
maximum occupancy period: <= 12 months (While the residence is being rebuilt.)
“period not to exceed twelve months while the residence is being rebuilt.”
Massachusetts General Laws Chapter 40A, Section 3 ↗Re-checked Sep 11, 2026
Accessory dwellingsAllowed (with conditions)
A single accessory dwelling unit, or its rental, in a single-family residential zoning district in Massachusetts cities and towns.
- The use may be subject to reasonable regulations, including applicable 310 CMR 15.000 requirements, site-plan review, dimensional setbacks, and bulk and height regulations.
- Municipal restrictions or prohibitions on short-term rental may apply.
- Owner occupancy of either the accessory dwelling unit or principal dwelling is not required.
- No more than one additional parking space may be required.
- No additional parking space may be required for an accessory dwelling unit located not more than 0.5 miles from a commuter rail station, subway station, ferry terminal, or bus station.
- More than one accessory dwelling unit, or rental thereof, in a single-family residential zoning district requires a special permit.
- The unit must otherwise satisfy the statutory definition, including sleeping, cooking, and sanitary facilities, a separate entrance, and a maximum gross floor area of the lesser of one-half the principal dwelling's gross floor area or 900 square feet.
maximum gross floor area: the lesser of 50% of the principal dwelling's gross floor area or 900 square feet · additional parking spaces: <= 1 space per accessory dwelling unit (No additional space may be required within 0.5 miles of a commuter rail station, subway station, ferry terminal, or bus station.)
“No zoning ordinance or by-law shall prohibit [...] a single accessory dwelling unit”
Massachusetts General Laws Chapter 40A, Section 3 ↗Re-checked Sep 11, 2026
Off-grid sanitationLimited
Alternative or off-grid sewage handling on parcels abutting a public sewer in a Massachusetts town.
- When a town has provided both a drain and a sewer in a public way, sewage must be connected to the sewer as directed by the responsible sewer authority.
- This claim does not establish a statewide rule for parcels without access to a public sewer.
“When a town has provided both a drain for waters and a sewer for sewage in a public way, the owner of every parcel of land abutting on such way or connected with such drain or sewer shall arrange his plumbing so that the waters shall be kept separate from the sewage; and shall make such connections with the drain and sewer respectively that the waters shall pass into the drain and the sewage into the sewer in accordance with the directions of the board or officer having charge of the repair and maintenance of sewers in such town.”
Massachusetts General Laws Chapter 83, Section 5 ↗Re-checked Sep 11, 2026
Agricultural exemptionAvailable (with conditions)
Commercial agriculture, aquaculture, silviculture, horticulture, floriculture, and viticulture land uses and related structures under Massachusetts local zoning law.
- The statutory protection applies when, during June, July, August, and September or during the harvest season of the primary crop, 25 percent of products for sale based on gross sales dollars or volume were produced by the owner or lessee on the parcel; alternatively, 25 percent were produced on the parcel and at least an additional 50 percent were produced in Massachusetts on other qualifying land.
- Activities may be limited to parcels of 5 acres or more, or to parcels of 2 acres or more in areas not zoned for the listed agricultural uses when annual sales generated from the use are at least $1,000 per acre based on gross sales dollars.
- Land divided by a public or private way or waterway is construed as one parcel for this section.
- The exemption does not exempt land or structures from floodplain or wetlands regulations established under the General Laws.
- Agriculture has the meaning given in Chapter 128, Section 1A; horticulture includes growing and keeping nursery stock and its sale.
- Agriculture, aquaculture, floriculture, and horticulture do not include marijuana-related growing, cultivation, distribution, or dispensation as described in the cited statutes, although a municipality may allow commercial marijuana growing and cultivation by zoning on land used for commercial agriculture, aquaculture, floriculture, or horticulture.
on-parcel production threshold: >= 25 percent (During June, July, August, September, or the primary crop’s harvest season; measured by gross sales dollars or volume.) · additional Massachusetts production threshold: >= 50 percent (Alternative test requiring at least 25 percent on-parcel production and additional production elsewhere in Massachusetts.) · minimum parcel size: >= 5 acres (Activities may be limited to parcels of 5 acres or more.) · alternative minimum parcel size: >= 2 acres (In areas not zoned for the listed agricultural uses, only if annual sales are at least $1,000 per acre based on gross sales dollars.) · annual sales threshold: >= 1000 USD per acre (Applies to the 2-acre alternative in areas not zoned for the listed agricultural uses.)
“nor shall any such ordinance or by-law prohibit, unreasonably regulate, or require a special permit for the use of land”
General Law - Chapter 40A, Section 3 ↗Re-checked Sep 11, 2026

Still unanswered

We looked and could not find an official answer yet. Silence is not permission — ask the county directly.

Building code adopted — Massachusetts building-code adoption applicable in Dukes County.
Inspections — Building inspections in Dukes County.
Certificate of occupancy — Certificates of occupancy in Dukes County.
Local zoning — Aggregate local zoning administered by municipalities and towns in Dukes County.
Minimum lot size — Minimum lot-size requirements in Dukes County.

15 more unanswered

Setbacks
Lot coverage
Building height
Living in an RV
Camping on your land
Septic permit
Septic inspection
Well permit
Mandatory utility hookup
Subdividing land
Driveway access
Building in a floodplain
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.

Living off-grid in Dukes County, Massachusetts

Is Dukes County a good place to live off-grid or homestead?

Dukes County scores 60/100 on the Bolthole Index, a solid county profile. Its strengths: a durable current and mid-century hazard profile and strong self-sufficiency basics: 47.1″/yr rainfall with little drought. Watch-outs: sparse surroundings — about 12,242 people within a 30-minute drive.

Do you need a building permit in Dukes County, Massachusetts?

Dukes County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by MassDEP Title 5 (310 CMR 15.000), enforced by the local Board of Health. Owner-builders may act as their own contractor to build their home. Rules change and cities within the county differ — always confirm with the county before you buy or build.

How much does land cost in Dukes County, Massachusetts?

Land in Dukes County runs about $8,824 per acre, based on the latest county data.

What is the water situation in Dukes County?

Dukes County gets about 47.1" of rain a year, with severe drought in roughly 4% of years.

How remote is Dukes County?

A typical private-land location has about 59,044 people within 15 miles and 9,626,184 within 100 miles. These radius catchments are the published fallback where road routing is unavailable.

Building permits, zoning and land rules in Dukes County, Massachusetts

At a glance

Who to call

Do you need a building permit in Dukes County, Massachusetts?

Who issues Dukes County building permits, and how do you reach the right office?

Does Dukes County have zoning?

How do septic permits work in Dukes County?

Can you live in an RV or tiny home on your land in Dukes County?

Building a home in Dukes County: the steps, in order

What should you check before buying land in Dukes County?

Watch-outs

Sources

Dukes County in Massachusetts

How Dukes County scores

Find land. Bring the promising ones back.

Parcel due diligence

Answers from the rulebook for Dukes County

Dukes County rules

Massachusetts rules that apply here

Still unanswered

Living off-grid in Dukes County, Massachusetts

Is Dukes County a good place to live off-grid or homestead?

Do you need a building permit in Dukes County, Massachusetts?

How much does land cost in Dukes County, Massachusetts?

What is the water situation in Dukes County?

How remote is Dukes County?

How Dukes compares in Massachusetts