Working With Us
Hiring an ADU builder in Chatham
Lower Cape ADU is a licensed accessory dwelling unit builder serving Chatham and the seven other Lower Cape towns. Our office is in North Eastham, at Unit #7, 4250 State Highway, about twenty-five minutes from Chatham. We work throughout Chatham, from the village out to the shore-side neighborhoods.
Chatham carries high property values alongside real coastal constraints: flood zones, conservation setbacks, and shifting shoreline rules. Siting an ADU well here protects both the project budget and the property value.
We handle Chatham 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 Chatham ADU project looks like
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Free consultation
We sit down with you — no charge, no obligation — and talk about what you are actually trying to solve on your Chatham property: rental income, room for family, a place to downsize into, or staying put as you age.
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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.
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Legal and physical limits
We establish what Chatham and the Massachusetts Affordable Homes Act actually allow on your parcel, so the design starts from a real envelope rather than a hopeful one.
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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.
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Permitting
We prepare and submit the permit package and represent the project before the Chatham Building Department, the Chatham Board of Health on septic or sewer questions, and the Conservation Commission for properties near wetlands or the shore as required.
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Construction supervision
We supervise construction through to occupancy, as a licensed Massachusetts Construction Supervisor working on your Chatham property.
What We Build
Types of ADUs we build in Chatham
Which of these fits depends on your lot, your septic or sewer situation, and what you are trying to accomplish. We work through that with you before recommending one.
Standalone Cottages in Chatham
A detached cottage on your own lot — the most flexible option when land and septic allow it.
Garage Conversions in Chatham
Converting an existing garage, or building above one, often on an already-approved footprint.
Basement Conversions in Chatham
A lower-level unit using space you already have, where ceiling height and egress work out.
Attic Conversions in Chatham
Overhead space turned into a compact unit without expanding the building footprint.
Modular & Prefab in Chatham
Factory-built units that shorten on-site construction time and tighten the schedule.
The Local Picture
Chatham combines high value with a real working waterfront
Chatham occupies the Cape's elbow, surrounded on three sides by water, with a postcard Main Street, the much-photographed Chatham Light, and a fishing fleet that still lands its catch at the pier. It's among the Cape's most sought-after addresses, which means property values are high and year-round housing is tight. For a Chatham homeowner sitting on valuable land, an ADU is a way to convert some of that value into income or a manageable downsizing home — without selling and leaving a town that's hard to replace.
Why an ADU Fits Here
Chatham character, Chatham opportunity
What makes Chatham Chatham—and how a well-designed accessory dwelling unit fits naturally into it.
Chatham Light & the Fish Pier
Chatham Light and the Fish Pier are the town's signature — a reminder that Chatham is both a resort and a working community. Year-round housing for that workforce is scarce, and an ADU can help supply it.
Main Street & the Resort Economy
Chatham's Main Street and summer economy generate steady seasonal rental demand, while the town's desirability keeps year-round rentals valuable too.
High Land Values
Chatham's strong property values mean an ADU can represent a meaningful financial tool — a way to put existing land to work for retirement income without selling the primary home.
Aging in a Town You Love
Many Chatham owners want to stay put as they age. A single-level, no-step ADU lets an owner downsize into easy living while keeping the larger house as a rental or for family.
The Rules, In Brief
Chatham ADU rules at a glance
How the statewide ADU law applies in Chatham — and what still gets decided locally.
By-Right, Statewide
Since February 2025, a first ADU is permitted by right in single-family zoning under the Affordable Homes Act, with no owner-occupancy requirement.
Size Limits
By-right ADUs are capped at 900 square feet or half the primary dwelling's floor area, whichever is smaller.
Coastal & Conservation Review
With water on three sides, many Chatham lots involve flood zones, coastal setbacks, or conservation review that influence where an ADU can be placed.
Local Dimensional Rules
Setbacks, height, and lot coverage stay town-set, and Chatham has been aligning its bylaw with state law — so current local specifics are worth confirming.
Local Knowledge
What to think about for a Chatham ADU
Chatham's defining feature — water on nearly every side — is also its main design consideration. Flood zones, coastal setbacks, and conservation review touch many properties here and can determine where, and how high, an ADU is built. The flip side is financial: Chatham's high land values mean a well-placed ADU can be a genuinely powerful retirement and income tool. For owners weighing whether to downsize in place rather than sell, that calculation often favors staying. We start by mapping your lot's flood and setback picture, then design an ADU that works within it while serving your financial goals.
Permitting an ADU in Chatham typically involves the Chatham Building Department, the Chatham Board of Health on septic or sewer questions, and the Conservation Commission for properties near wetlands or the shore. We prepare the package and represent the project through that process as part of every job.
Common Questions
Chatham ADU questions we get asked
Do I need a special permit to build an ADU in Chatham?
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 Chatham 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 Chatham?
The by-right cap is 900 square feet or 50% of the primary dwelling’s floor area, whichever is smaller. On a modest Chatham 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 Chatham property?
Chatham has invested heavily in municipal sewer and many properties are now connected, though others remain on private septic. Sewer availability, along with flood zone and conservation setbacks, is a primary driver of what is possible on a given Chatham lot. We confirm all of it before design.
How long does an ADU project take in Chatham?
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 Chatham property at the consultation rather than a generic range.
Can I rent out an ADU in Chatham?
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 Chatham rules before you build. We raise this early because it can change which design makes sense.
Let's Talk
Thinking about an ADU in Chatham?
The first conversation is free. Tell us about your Chatham 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 ConsultationVern Hatt · Licensed Construction Supervisor #CS62739 · Home Improvement Contractor #177590