Eastham · Cape Cod

ADU Builder in Eastham, Massachusetts

Gateway to the Outer Cape — and to a smarter way to stay in the home you love. An accessory dwelling unit lets Eastham homeowners add income, age in place, and downsize without leaving town.

Working With Us

Hiring an ADU builder in Eastham

Lower Cape ADU is a licensed accessory dwelling unit builder serving Eastham and the seven other Lower Cape towns. Our office is in North Eastham, at Unit #7, 4250 State Highway next to Ace Hardware — so Eastham is not a town we drive to, it is the town we work in every day.

Eastham projects live or die on septic capacity. Knowing before design starts whether your Title 5 system can carry another bedroom is the difference between a project that moves and one that stalls after you have already paid for drawings.

We handle Eastham ADU projects end to end — site assessment, design, permitting, and construction supervision — so you are working with one accountable party from the first conversation through to occupancy, rather than coordinating a designer, an expediter, and a contractor yourself.

  • Vern Hatt, owner
  • MA Construction Supervisor License #CS62739
  • MA Home Improvement Contractor License #177590
  • Office in North Eastham

What an Eastham ADU project looks like

  1. Free consultation

    We sit down with you — no charge, no obligation — and talk about what you are actually trying to solve on your Eastham property: rental income, room for family, a place to downsize into, or staying put as you age.

  2. Property assessment

    We walk the property and look at the things that decide the project: lot area, setbacks, septic or sewer, grade, access, and what the existing house can support.

  3. Legal and physical limits

    We establish what Eastham and the Massachusetts Affordable Homes Act actually allow on your parcel, so the design starts from a real envelope rather than a hopeful one.

  4. Preliminary design and estimate

    We produce a preliminary design and a good-faith estimate as part of the bidding process, so you can see the project and its cost before committing to anything.

  5. Permitting

    We prepare and submit the permit package and represent the project before the Eastham Building Department, the Eastham Board of Health for septic review, and where a project calls for it, the Zoning Board of Appeals or Conservation Commission as required.

  6. Construction supervision

    We supervise construction through to occupancy, as a licensed Massachusetts Construction Supervisor working on your Eastham property.

Talk to an ADU builder about your Eastham property. The first conversation is free.

508-255-3788

The Local Picture

We're based right here in Eastham

Our office sits at 4250 State Highway in North Eastham, next to Ace Hardware — so Eastham isn't just a town we serve, it's where we work every day. Eastham anchors the entrance to the Outer Cape, where Route 6 narrows and the National Seashore begins. It's a town of year-round neighbors, summer visitors, and a housing market squeezed between the two. For longtime residents, an ADU offers a way to put existing land to work without giving up the address, the neighbors, or the life they've built here.

Why an ADU Fits Here

Eastham character, Eastham opportunity

What makes Eastham Eastham—and how a well-designed accessory dwelling unit fits naturally into it.

Cape Cod National Seashore

National Seashore Gateway

Eastham holds the Salt Pond Visitor Center and the gateway to the National Seashore. That protected setting keeps the town desirable for year-round and seasonal renters alike — and it means a well-designed ADU sits in a community where housing stays in demand and short supply.

Bay & Ocean

First Encounter & the Bay Side

From First Encounter Beach on the bay to the Atlantic-facing Seashore, Eastham's two coastlines define its character. A single-level cottage or garage conversion can give an aging owner a comfortable, low-maintenance home while the larger house becomes a year-round rental.

Local Landmarks

Nauset Light & Three Sisters

Eastham's iconic Nauset Light and the Three Sisters lighthouses speak to a town proud of its heritage. ADU design here respects that scale — modest, subordinate units that fit quietly behind or beside the primary home.

The Housing Reality

Year-Round Housing Pressure

Eastham works hard to keep year-round residents and essential workers housed. An ADU is one of the gentlest tools available: it adds a home without changing the neighborhood, using land and infrastructure that already exist.

The Rules, In Brief

Eastham ADU rules at a glance

How the statewide ADU law applies in Eastham — and what still gets decided locally.

By-Right, Statewide

Since February 2025, the Massachusetts Affordable Homes Act allows a first ADU by right in single-family zoning — no special permit or owner-occupancy requirement for that first unit.

Size Limits

A by-right ADU is capped at 900 square feet or 50% of the primary dwelling's floor area, whichever is smaller. Larger or second units may require additional local review.

Septic & Title 5

Like most of the Outer Cape, Eastham relies on private septic. Title 5 capacity is often the single biggest design driver here — we assess it early so there are no surprises.

Local Bylaw Reconciliation

Eastham has been updating its local ADU bylaw to align with state law. Setbacks, height, and short-term-rental rules are still set at the town level, so current details matter.

Local Knowledge

What to think about for an Eastham ADU

Two factors shape most Eastham projects. The first is septic: many lots are served by Title 5 systems sized for the existing house, so adding bedrooms can trigger an upgrade. We evaluate your system's capacity at the very start, because it often determines whether a detached cottage, a garage conversion, or a within-the-footprint reconfiguration is the most cost-effective path. The second is the Seashore and resource overlays — properties near protected land or wetlands may carry extra setback or conservation review. None of this is a barrier; it's simply why an Eastham ADU benefits from local experience and an early, honest assessment.

Permitting an ADU in Eastham typically involves the Eastham Building Department, the Eastham Board of Health for septic review, and where a project calls for it, the Zoning Board of Appeals or Conservation Commission. We prepare the package and represent the project through that process as part of every job.

Please verify current local rules. ADU requirements are evolving as Eastham reconciles its local bylaw with the Massachusetts Affordable Homes Act. The summaries here are general guidance, not legal advice. Always confirm setbacks, septic requirements, height, lot coverage, and short-term-rental rules with the Eastham building and planning departments before relying on them. We help our clients do exactly that as part of every project.

Common Questions

Eastham ADU questions we get asked

Do I need a special permit to build an ADU in Eastham?

Under the Massachusetts Affordable Homes Act, a first accessory dwelling unit is allowed by right in single-family zoning, which means a special permit is generally not required for that first unit. You still need a building permit, and Eastham still applies its own setback, height, and lot coverage rules. Second units, oversized units, or properties in overlay districts may require additional local review. We confirm the current requirements with the town as part of every project.

How big can an ADU be in Eastham?

The by-right cap is 900 square feet or 50% of the primary dwelling’s floor area, whichever is smaller. On a modest Eastham home, the 50% figure is often the binding number rather than the 900 square feet — which is why we measure the existing house early instead of assuming.

Will septic or sewer limit an ADU on my Eastham property?

Eastham has municipal water but no town sewer, so nearly every Eastham ADU depends on private septic. Title 5 capacity is usually the first thing that decides whether a project is feasible and what size it can be. We check your system’s rated capacity before any design work begins, because adding a bedroom can trigger an upgrade.

How long does an ADU project take in Eastham?

Design and permitting typically run a few months, and construction depends on the type of unit and the season. Garage, basement, and attic conversions generally move faster than new detached construction. We give you a realistic schedule for your specific Eastham property at the consultation rather than a generic range.

Can I rent out an ADU in Eastham?

Long-term rental of an accessory dwelling unit is generally permitted. Short-term rental rules are set locally and vary meaningfully from town to town on the Lower Cape, so if short-term rental income is part of your plan, confirm current Eastham rules before you build. We raise this early because it can change which design makes sense.

Across the Lower Cape

ADU builders for every Lower Cape town

We serve all eight Lower Cape towns. Explore the others, or reach out about Eastham.

Let's Talk

Thinking about an ADU in Eastham?

The first conversation is free. Tell us about your Eastham property and what you are trying to solve — rental income, family space, or downsizing in place — and we will walk you through whether it makes sense, with a preliminary design before any estimate.

Start with a Free Consultation

Vern Hatt · Licensed Construction Supervisor #CS62739 · Home Improvement Contractor #177590