How Long Does It Take to Build an ADU in Massachusetts? A Realistic Timeline for Homeowners
When homeowners begin exploring an Accessory Dwelling Unit (ADU) project, one of the first questions we hear is: “How long will this take?”
The truth is, building an ADU in Massachusetts isn’t a weekend project—but with the right team and process, it can be smooth, efficient, and well worth the investment. The key is understanding what goes into each phase and planning ahead.
Here’s a look at the real timeline—from your first inquiry to move-in day—and how Mass ADU keeps things moving every step of the way.
Phase 1: Property Review + Zoning (1–2 Weeks)
Every project starts with evaluating your specific lot. Just because ADUs are allowed in your town doesn’t mean your property qualifies. Zoning laws, setbacks, lot coverage limits, and overlays (like wetlands or historic districts) all come into play.
At Mass ADU, we:
Review your lot and zoning regulations
Conduct a feasibility analysis
Walk your property to evaluate access and layout options
This step is quick but critical—it sets the foundation for everything that follows.
Phase 2: Design + Survey (4–6 Weeks)
Once your property is confirmed eligible, we move into design. This phase includes:
Bringing in a licensed surveyor to map the property
Working with an architect (ours or yours) to create a custom plan
Reviewing the design with you to ensure it fits your needs and complies with local regulations
Design often takes 4–6 weeks, depending on how quickly homeowners provide feedback. Rushing this step can lead to costly revisions—so we encourage thoughtful, collaborative input.
Phase 3: Permitting Process (6–12 Weeks)
This is where timelines can vary most depending on the town. Massachusetts doesn’t have a statewide ADU permitting standard—each municipality sets its own process.
Permitting may involve:
Zoning board hearings
Conservation commission review
Building department approval
Neighbor notifications
Mass ADU handles all application preparation and communication with town officials, helping prevent delays due to missing paperwork or technical errors. We keep you updated every step of the way, so you’re never left wondering.
Phase 4: Construction (3–5 Months)
Once permits are approved, the fun part begins: building your ADU.
Construction timelines depend on the type of unit (detached, garage conversion, basement suite), the season, and the complexity of the build. Generally, our builds take 3 to 5 months from start to finish.
We manage:
Site prep and excavation
Foundation work
Framing, plumbing, electric, and finishing
Final inspections and occupancy sign-off
Because ADUs are often close to the main home, we work carefully to minimize disruption to your daily life.
How Mass ADU Shortens the Learning Curve
Many homeowners lose time simply trying to figure out where to start. We eliminate that uncertainty.
With Mass ADU, you get:
A team that knows local bylaws in towns across Massachusetts
Vetted professionals (surveyors, architects, engineers)
Permitting experience in dozens of municipalities
Weekly updates and clear next steps
We don’t just manage construction—we guide the entire process, so you avoid costly missteps and frustrating delays.
Why Planning Early Matters More Than Building Fast
ADUs are in high demand, and towns are still adjusting to accommodate them. That means:
Architects, surveyors, and inspectors book up quickly
Town reviews may take longer if submission volumes spike
Last-minute changes can derail a great plan
Even if you're not ready to build tomorrow, starting the planning process now can save you time (and money) down the road
Ready to Take the First Step?
If you're thinking about building an ADU in Massachusetts, don’t wait for the “perfect time.” The process starts with a conversation—and we’re here to walk it with you, step by step.
📞 Call us at (617) 7
