ADU builder for the South Shore
An Accessory Dwelling Unit (ADU) is a smaller, self-contained home on the same lot as your main house — with its own kitchen, bath, and entrance. Thanks to Massachusetts' Affordable Homes Act, homeowners can now add one by right in single-family zones, making ADUs one of the smartest ways to house family, generate rental income, or add long-term value. Jennifer Construction designs and builds them end to end across the South Shore.
Free ADU Consultation
Find out what your lot allows by right.
ADUs are now allowed by right in Massachusetts
The Affordable Homes Act lets homeowners build one Accessory Dwelling Unit of up to 900 sq ft by right in single-family zoning districts statewide — no special permit or zoning variance required. Local building codes and reasonable dimensional rules still apply, and that's exactly the process we handle for you.
- One ADU up to 900 sq ft (or half the main home's size, whichever is smaller) allowed by right
- No special permit needed in single-family zoning districts
- Owner-occupancy cannot be required as a condition in most cases
- Standard building permits and inspections still apply — we manage them for you
Three ways to add an ADU.
Detached ADU
A standalone backyard cottage — the most private and flexible option, ideal for rental income or multigenerational living.
Attached ADU
A new addition connected to your existing home, such as an in-law suite with its own entrance, kitchen, and bath.
Conversion ADU
Converting existing space — a garage, basement, or attic — into a fully independent dwelling unit.
The value of an ADU.
Rental Income
Generate steady monthly income by renting your ADU long-term.
Multigenerational Living
Keep aging parents or adult children close with independent, private space.
Added Property Value
A well-built ADU can meaningfully increase your home's resale value.
Flexible Use
Home office, guest house, or future downsizing option — your needs can change over time.
How we build it.
- 1
Free Consultation
We review your lot and goals and confirm what your zoning allows by right.
- 2
Design & Feasibility
We plan the ADU type, size, and layout and prepare drawings for permitting.
- 3
Permitting
We file the application and coordinate with your city or town's building department.
- 4
Construction
Our insured crew builds it end to end — site work, foundation, framing, roof, siding, and interior finishes.
- 5
Final Inspection & Handover
We pass inspection, walk you through the unit, and back the work with our warranty.
What does an ADU cost?
ADU costs vary widely with type, size, site conditions, and finishes — a garage conversion and a new detached cottage are very different projects. Rather than quote a misleading number, we provide a free on-site consultation and a clear written estimate, and we offer financing to help spread the investment.
ADU construction across Massachusetts.
We build ADUs throughout the South Shore and Greater Boston. Explore ADU rules and options in your county.
Common questions about ADUs.
What is an ADU?+
An Accessory Dwelling Unit is a smaller, independent home on the same lot as a single-family house. It has its own kitchen, bathroom, and separate entrance, and can be detached, attached, or created by converting existing space.
Can I build an ADU by right in Massachusetts?+
Yes. Under the Affordable Homes Act, effective February 2, 2025, a single ADU of up to 900 sq ft is permitted by right in single-family zoning districts statewide — no special permit or variance required. Local building codes and reasonable dimensional standards still apply.
How large can my ADU be?+
The by-right limit is 900 square feet, or half the size of your principal dwelling, whichever is smaller. A larger ADU may still be possible with local approval.
Do I have to live on the property?+
In most cases the law prevents towns from requiring owner-occupancy as a condition for a by-right ADU, which makes renting one out more feasible than under the old rules. We'll confirm the specifics for your municipality.
How long does it take to build an ADU?+
It depends on the type. A conversion can move quickly, while a new detached ADU takes longer for site work, foundation, and full construction. We give you a realistic timeline during your consultation.
Can you help with financing?+
Yes. ADUs are a significant investment, and we offer flexible financing options. See our financing page or ask during your free consultation.
Ready to explore an ADU?
Get a free, no-obligation consultation and find out exactly what your Massachusetts lot allows by right.