ADU BUILDER — GLASTONBURY, CT
Detached ADUs & In-Law Suites Built for Glastonbury.
Glastonbury's generous lot sizes and suburban character make it one of the best towns in Connecticut for detached ADU builds, backyard cottages, and attached in-law additions. We design, permit, and build them all.
25+Years Experience
500+Projects Completed
★ 4.9Google Rated
100%Licensed & Insured
PROUD TO USE INDUSTRY-LEADING BRANDS
WHAT WE BUILD IN GLASTONBURY
Your Glastonbury lot has more potential than you think.
Glastonbury homeowners sit on some of Hartford County's most spacious residential lots — and that space is an opportunity. Whether you want a detached backyard cottage for a family member, a carriage house with a living unit above the garage, or an attached in-law suite added to your existing home, Connecticut's 2026 ADU law has made all of these more accessible than ever.Lagace Construction has been building across Glastonbury and Hartford County for over 25 years. We know the local building department, the zoning nuances in South Glastonbury vs. the main center, and the site conditions that affect ADU cost and feasibility.- Detached ADU cottages & carriage houses
- Garage-with-living-above on existing or new garage
- Attached in-law wing additions with private entrance
- Basement ADU conversions with full egress
- Glastonbury zoning research & septic assessment
- Full permits, engineering, & CO inspection — in-house
GLASTONBURY ADU ADVANTAGE
Larger lots. More ADU options.
Many Glastonbury properties have the lot depth and setback clearance to accommodate a detached structure — giving you the most private, most versatile ADU option available.
Detached means fully independent.
A detached ADU — a freestanding structure on your Glastonbury property — gives you the cleanest separation between your home and the second unit. That independence is ideal for aging parents who want privacy, adult children establishing independence, or tenants you'd prefer not to share walls with.For properties on town sewer, detached ADUs are straightforward. On septic? We assess the existing system capacity and, if needed, work with a licensed engineer to determine the upgrade path before you commit to a build.- Detached units: maximum privacy & resale value
- Septic assessment included in free consultation
- Utility tie-in coordinated with town & utility providers
- Licensed & insured: CT NHC #NHC-0016939
25+Years CT Experience
500+Projects Built
100%In-House Crew
★ 4.9Google Rated
INVESTMENT GUIDE
What does an ADU cost in Glastonbury?
Glastonbury pricing aligns with Hartford County norms. Site conditions — lot size, utilities, septic — affect final cost. Here's a realistic range.Basement Conversion
$85K – $155K
Convert your existing Glastonbury basement into a fully permitted, self-contained living unit with its own entrance.- Egress windows & exterior door
- Full kitchen & bathroom
- Separate electrical panel
- Permits & CO included
Attached In-Law Addition
$160K – $310K
A new addition attached to your Glastonbury home — designed as a completely self-contained unit with private entry.- Private entrance & utility hookups
- Full kitchen, bedroom, bath
- Tied into existing structure
- Full design-build service
Detached ADU / Cottage
$215K – $470K
A fully independent structure on your Glastonbury lot — cottage, carriage house, or garage-with-living-above. Best for large lots.- New foundation & structure
- Full utilities & mechanicals
- Maximum privacy for all parties
- Highest rental income potential
YOUR QUESTIONS ANSWERED
Frequently Asked Questions — ADUs in Glastonbury
Are ADUs allowed in Glastonbury, CT?
Yes. Connecticut's 2026 ADU law requires Glastonbury — like all CT municipalities — to allow at least one ADU per single-family residential lot by right or with a simple permit. Specific rules cover setbacks, maximum unit size (typically capped at a percentage of the primary home's floor area), and design standards. We walk through your parcel's specific rules during your free site visit.Can I build a detached ADU in Glastonbury if I'm on septic?
Possibly, yes — but it requires a septic assessment. Adding a second dwelling unit adds wastewater load to your system. We include a septic feasibility review in our free consultation. If an upgrade is needed, we can refer you to a licensed engineer for system design, and incorporate that scope into the overall project.How long does an ADU project take in Glastonbury?
Basement conversions typically run 12–16 weeks after permits are issued. Attached additions run 4–6 months. Detached new-builds run 6–9 months. Glastonbury permitting generally takes 4–8 weeks. We submit your applications within 2–3 weeks of finalizing the design and use that window to prep materials and schedule crews.What's the rental income potential for a Glastonbury ADU?
Glastonbury's proximity to Hartford, East Hartford employment centers, and strong school district means steady rental demand. A well-finished detached ADU in Glastonbury can rent for $1,400–$2,200/month depending on size and finish. At those rates, a basement conversion typically pays back its construction cost in 6–8 years.Do you do the full project or do I need to hire my own architect?
We handle everything in-house: design, engineering, permit drawings, permit applications, all trades (framing, plumbing, electrical, HVAC, tile, finish work), and final certificate of occupancy. No separate architect needed. One point of contact, one contract, one crew. START YOUR PROJECT
Book a free, no-pressure quote.
Pick a time that works for you. Scott or one of our project leads will visit your home, walk the project with you, and follow up with a clear written estimate — usually within 5 business days.- On-site consultation, no obligation
- Line-itemized written estimate
- Real timelines and a real start date
- CT Licensed & Insured (Reg. #NHC-0016939)
Prefer to call? Reach Scott directly at (860) 933-2700
Serving Hartford & Tolland Counties
Based in Andover, CT — building ADUs and additions across central and eastern Connecticut for over 25 years.
GlastonburyWest HartfordFarmingtonHebronCoventryBoltonManchesterTollandAndoverColumbiaEast HamptonMarlboroughVernonWindsorSouth Glastonbury
