Permits for patios, walls and fire pits on Cape Cod
What needs a permit or a town sign-off before hardscape work on Cape Cod, in plain words, with the official source for every rule. Checked on October 2, 2026. Rules change and every town has its own offices, so confirm with yours before you build.
At a glance
| The job | State building permit | Also check |
|---|---|---|
| Retaining wall up to 4 ft, measured from the bottom of the footing | Not required, unless it holds up a surcharge | Conservation Commission near wetlands; historic district |
| Retaining wall over 4 ft | Required | A licensed construction supervisor on site at set stages |
| Driveway or walkway | Not required | Town permit for any work in the road layout; Conservation Commission near wetlands |
| Patio | Not on the exempt list: ask your building department | Conservation Commission near wetlands |
| Fire pit or outdoor fireplace | Not on the exempt list: ask your building department | Your fire district's rules; historic district |
| Drywell or drainage | Not on the exempt list: ask your building department | Title 5 distances from the septic system; trench permit if deeper than 3 ft |
Retaining walls
Under the Massachusetts State Building Code, a retaining wall that is not over 4 feet tall does not need a building permit, unless it supports a surcharge, such as a driveway, a slope or a structure above it. The 4 feet are measured from the bottom of the footing to the top of the wall, so the buried part counts.
Over 4 feet, the wall needs a permit, and once a wall is more than 4 feet above grade, the licensed construction supervisor has to be on site at the stages the code lists. Older summaries online say "unbalanced fill" or a 6-foot fence limit: that was the 8th edition. The 10th edition has been the only code in effect since July 1, 2025.
Driveways, walkways and aprons
Driveways and sidewalks are on the code's list of work exempt from a building permit for one- and two-family homes. Work inside the town road layout is not exempt:
- Barnstable (Hyannis and the other villages): any driveway work in a town road or right-of-way needs a permit from the DPW Engineering Division, filed at least five business days ahead, by a contractor licensed with the Engineering Division and bonded. The part of a driveway inside the public way must be asphalt or concrete for at least 10 feet back from the road.
- Yarmouth: digging inside the town road layout needs a Road Opening Permit from the Engineering Division.
- Routes 6, 6A and 28 are state roads: a driveway onto them needs a MassDOT Highway Access Permit.
Near wetlands, ponds and the shore
Work within 100 feet of a wetland, or within 200 feet of a river, goes to the town Conservation Commission before it starts. If you are not sure the rules apply, you can file a Request for Determination of Applicability; if the work would alter the area, you file a Notice of Intent. Cape towns add their own bylaws on top of the state rules:
- Barnstable keeps a 50-foot undisturbed buffer from the wetland, and its rules count patios, landscape walls and even gravel or shell paving as hardscape.
- Yarmouth protects the 100-foot buffer itself, and the state's exemptions do not apply. No new structures within 50 feet of a resource area; minor structures up to 140 square feet in total, such as pervious patios, may be allowed as close as 35 feet.
- Dennis: nothing closer than 50 feet to a wetland resource area, apart from water-dependent projects.
Fire pits and outdoor fireplaces
State rules allow a fire for cooking; other fires fall under the open burning regulation. The fire departments set the details, and they differ:
- Yarmouth and Hyannis: no special permit, but the fire must be for cooking, under 3 feet across, at least 25 feet from the house, shed, garage or deck, and watched by an adult until it is out.
- West Barnstable: its guidance says no permit is needed to install and use a fire pit; clean firewood only, never under a roof or awning.
- Burning brush is a different thing: January 15 to May 1 only, 10 am to 4 pm, more than 75 feet from any home, with a permit from your fire department.
In Yarmouth's Old King's Highway Historic District (everything north of Route 6), the committee approves stone walls, built-in seating and permanent fireplaces. Ground-level patios, walkways and driveways do not go to the committee.
Drainage and drywells
Under Title 5, a drywell has to sit at least 10 feet from the septic tank and 25 feet from the leaching field, and no driveway or other impervious surface goes over the leaching field unless there is no other way. A stormwater drywell on a single-family property is exempt from MassDEP registration. Any trench deeper than 3 feet needs a trench permit from the town, even on private land.
Before anyone digs
Massachusetts law requires marking the area in white and notifying Dig Safe (call 811) at least 72 hours ahead, not counting weekends and holidays. The ticket lasts 30 days, and when a contractor does the digging, the ticket is the contractor's. Town water and sewer lines and private lines may not be marked.
This page is a plain summary of public rules, not legal advice. Your town's building department, conservation office and fire district have the final word.
Questions
Do I need a permit for a retaining wall in Massachusetts?
Not under the state building code if the wall is not over 4 feet tall, measured from the bottom of the footing to the top of the wall, and it does not hold up a surcharge such as a driveway or a slope. Over 4 feet it needs a building permit. Near wetlands or in a historic district the town may need to approve it anyway.
Can I build a patio near a wetland on Cape Cod?
Work within 100 feet of a wetland goes to the town Conservation Commission first. Barnstable keeps a 50-foot undisturbed buffer and counts patios as hardscape. Yarmouth allows no new structures within 50 feet, with minor ones up to 140 square feet, such as pervious patios, possibly allowed as close as 35 feet.
Can I use a fire pit in Yarmouth or Hyannis?
Yes, without a special permit, if the fire is for cooking, under 3 feet across, at least 25 feet from the house, shed, garage or deck, and an adult watches it until it is out. Other fire districts have their own rules, so check yours.
Do I need to call Dig Safe before a patio or a wall?
Yes. Massachusetts requires marking the area in white and notifying Dig Safe at 811 at least 72 hours ahead, not counting weekends and holidays. When a contractor digs, the ticket is the contractor's.