ADU & Garage Apartment Builder in Connecticut
Accessory dwelling units and garage apartments that add real, flexible living space — for aging parents, adult children, guests, a home office, or rental income.
In short: An ADU (accessory dwelling unit) is a self-contained living space on the same property as a home — often above or attached to a garage. In Connecticut, a garage apartment or ADU typically costs from roughly $200,000 to $500,000+ depending on size, the garage below, and finishes. Thomas Construction designs, permits, and builds ADUs and garage apartments statewide.
Flexible living space, done right
An accessory dwelling unit is one of the smartest ways to add living space and long-term value to a property. It can house aging parents close by, give an adult child independence, welcome guests, serve as a private home office or studio, or generate rental income. Most of the ADUs we build are garage apartments — finished living space above or beside a custom garage — but we also build attached in-law suites and standalone units.
ADUs are deceptively complex: they involve zoning, building code, utilities, egress, and sometimes septic capacity. As a veteran-owned, licensed design-build contractor, we manage all of it — so you get a comfortable, code-compliant, beautifully finished space without the headaches.
Benefits of an ADU
- Multigenerational living — keep family close while everyone keeps their independence.
- Rental income — a well-built ADU can offset a mortgage or fund retirement.
- Flexibility — guest suite now, office later, rental after that.
- Property value — adds usable square footage and appeal.
- Efficiency — pairing an ADU with a new detached garage maximizes value from one project.
Common ADU configurations
- Garage apartments: a full apartment above a two- or three-car garage, with private entry and stairs.
- Attached in-law suites: living space connected to the main home — see home additions.
- Detached ADUs: a separate small cottage or unit on the property.
- Finishes: full kitchen, bath, laundry, mini-split climate control, and the same quality finishes as a main home.
Design considerations
A great ADU lives larger than its square footage. We focus on:
- Layout efficiency: smart floor plans that feel open and functional.
- Privacy & access: separate entries, parking, and sound separation.
- Accessibility: single-level or first-floor options for aging in place.
- Utilities: heating, plumbing, electrical, and how the ADU ties into existing systems or septic.
- Light & comfort: windows, ceiling height, and finishes that make it a real home.
Connecticut ADU considerations
- Zoning & local rules: Connecticut has encouraged ADUs statewide, but each town sets specific rules on size, parking, owner-occupancy, and whether they are allowed by-right. We confirm what your town permits.
- Septic capacity: properties on septic must have adequate capacity for the added bedrooms; we coordinate evaluation and any upgrades. See septic & foundation work.
- Egress & code: bedrooms and stairs must meet building and fire codes.
- Permitting: we handle zoning approvals and building permits.
Our construction process
- Consultation — we discuss who the ADU is for and what you want it to do.
- Feasibility & design — we confirm zoning and septic, then design the unit.
- Proposal & permitting — detailed proposal, drawings, and approvals.
- Foundation & shell — foundation, framing, and enclosure (often with the garage below).
- Systems & finishes — kitchen, bath, mechanicals, and quality finishes.
- Final walkthrough — reviewed together and backed by our 2-year craftsmanship warranty.
Why build your ADU with us
ADUs reward experience. We understand Connecticut zoning, septic, and code, and we manage the whole project as one team — so you end up with a comfortable, compliant, beautifully built living space and a single point of contact throughout.
Questions homeowners ask us
Most garage apartments and ADUs run from roughly $200,000 to $500,000+ depending on size, whether a garage is built below, and finish level. Building the ADU together with a new garage is often the best value. We provide a detailed proposal after assessing your property.
Yes. Connecticut has encouraged accessory dwelling units statewide, but each municipality sets its own rules on size, parking, and approval. We confirm exactly what your town allows before design.
In many Connecticut towns, yes — though some have owner-occupancy or short-term rental rules. We help you understand the local regulations that apply to your property.
Possibly. Added bedrooms increase septic demand, so properties on septic need adequate capacity. We coordinate evaluation and any required upgrades as part of the project.
An ADU is a self-contained living unit with its own kitchen, bath, and entrance. A home addition expands your existing living space without necessarily being independent. We build both and can advise which fits your goals.
Thinking about an ADU or garage apartment?
We will help you navigate Connecticut ADU rules and design a space that fits your family and property.