If you’ve ever thought about adding an in-law apartment to your home — a place where aging parents could live close by, or where adult children could have their own space without paying city rent — there’s never been a better time to explore it in Connecticut.
Thanks to major changes in Connecticut state law over the past few years, accessory dwelling units (ADUs) are now a realistic option for many homeowners across eastern CT. Here’s what changed, what it means for your property, and how an ADU could be one of the smartest investments you make for your family.
What Is an ADU?
An Accessory Dwelling Unit — commonly called an in-law apartment, granny flat, or backyard cottage — is a second, smaller living space on the same lot as your primary home. It can be:
- Attached — a converted garage, basement apartment, or addition connected to the main house
- Detached — a separate cottage or studio structure in the backyard
- Interior — a basement or attic converted into a fully self-contained unit
ADUs have their own entrance, kitchen, bathroom, and sleeping area — a fully independent living space, just at a much smaller scale than a traditional home.
What Changed in Connecticut Law
For decades, zoning laws across most of Connecticut made it extremely difficult — or outright impossible — to add a second dwelling unit to a single-family property. That began to change in 2021.
Public Act 21-29, signed into law in 2021, was one of the most significant housing reforms Connecticut had seen in a generation. The law amended Connecticut General Statutes § 8-2 and required every municipality in the state to allow at least one ADU on any single-family lot — without requiring a zoning variance, special permit, or public hearing. Under the state baseline rules:
- ADUs can be attached or detached
- Maximum size is 1,000 square feet or 30% of the primary home’s square footage (whichever is less)
- Towns cannot require more than one parking space per ADU
- Towns cannot restrict occupancy exclusively to family members
The law included an opt-out provision that allowed towns to write their own local ADU regulations instead of following the state standard. Over 100 Connecticut municipalities opted out by the January 2023 deadline — but opting out doesn’t mean banning ADUs. It simply means those towns set their own rules, which vary from town to town.
The bottom line: Whether your town opted out or not, ADUs are now a permitted option across Connecticut. The question is what the specific requirements are in your municipality.
What This Means for Homeowners in Eastern CT
For homeowners in towns like Tolland, Coventry, Andover, Hebron, Glastonbury, Colchester, Windham, and Marlborough, the change in state law has opened a real door that simply wasn’t there before.
Every town handles things slightly differently — setback requirements, size limits, and design standards can vary — so the first step is always checking with your local zoning office. But the days of being flatly denied because “we don’t allow second units” are largely behind us.
At Lagace Construction, we help homeowners navigate both the zoning piece and the actual build. We’ve been building and remodeling in eastern Connecticut for over 20 years, and we know how to work within local requirements to get your project done right.
The Multi-Generational Living Advantage
One of the biggest reasons homeowners are turning to ADUs right now is multi-generational living — and it makes a lot of sense.
Consider the numbers: the average assisted living facility in Connecticut costs over $5,000 per month. A one-bedroom apartment in the Hartford area averages $1,400–$1,800/month. Meanwhile, building an ADU on your property — a real, permanent structure tailored to your family’s needs — can cost significantly less over the long run and adds lasting value to your home.
An ADU lets you:
- Keep aging parents close — independent enough to maintain privacy and dignity, close enough to provide care and peace of mind
- House adult children — give them a real start without paying rent to a stranger, while keeping the family together
- Generate rental income — when the unit isn’t needed for family, it can be rented out to offset your mortgage or property taxes
- Add long-term property value — a well-built ADU increases your home’s resale value and marketability
It’s not just a housing solution — it’s a family solution.
What Does It Cost to Build an ADU?
Costs vary widely depending on the type of ADU, the size, and site conditions. As a general guide:
- Basement conversion: Often the most affordable option, typically $40,000–$80,000 depending on the scope of work
- Garage conversion: $50,000–$100,000+, depending on insulation, plumbing, and finishing level
- Addition (attached ADU): $150,000–$250,000+, depending on size and foundation requirements
- Detached cottage/backyard structure: $120,000–$250,000+, depending on size and utilities
These are ranges, not guarantees — every property is different. But compared to the cost of senior housing or moving to a larger home, building an ADU is often the most cost-effective path for families planning ahead.
Ready to Explore Your Options?
If you’re a homeowner in eastern Connecticut thinking about adding an in-law apartment or accessory dwelling unit, we’d love to talk. Lagace Construction specializes in residential additions, remodels, and new construction — and we can help you figure out what’s possible on your property.
Give us a call at (860) 933-2700 or reach out through our website to schedule a free consultation. Let’s talk about what makes sense for your family and your home.
Lagace Construction — Building in Eastern Connecticut Since 2001. Licensed CT New Home Construction Contractor #NHC-0016939.
