Step-by-Step Guide to Permitting an ADU in Your City
Everything You Need to Know About Getting Approved to Build Your ADU
If you’re thinking about building an Accessory Dwelling Unit (ADU) on your property in Massachusetts, there’s good news: a 2024 state law now allows ADUs by right in many communities across the Commonwealth.
But even with the law on your side, you still need local permits — and every city has its own process.
Here’s your step-by-step guide to getting an ADU permitted, no matter where you live in Massachusetts.
✅ First: Know the Law
In 2024, Massachusetts passed a law requiring all cities and towns to allow at least one ADU on single-family lots. This means you no longer need a special variance in many cases — as long as your ADU meets local zoning and building codes.
🔍 Important: Each city or town can still set its own rules for things like:
- Size limits
- Setbacks and height
- Owner occupancy
- Parking
- Number of bedrooms
At ADULink, we help homeowners navigate these differences — at no cost.
📋 Step-by-Step: Permitting Your ADU in Massachusetts
1️⃣ Property & Zoning Review
Goal: Determine if your property qualifies and under what conditions.
✔️ Review your city’s ADU ordinance
✔️ Check lot size, existing structures, and zoning district
✔️ Identify any special restrictions (e.g., conservation zones)
👉 Don’t want to do this yourself? Let us check your zoning for free
2️⃣ Preliminary Site Plan
Goal: Sketch out your proposed ADU — location, size, access, and setbacks.
✔️ Use a plot plan or survey of your property
✔️ Decide on ADU type: detached, attached, basement, garage conversion
✔️ Ensure compliance with setback and size rules
In many cities, ADUs must be under 900 sq ft or no more than 50% of the main house’s size.
3️⃣ Design & Architectural Plans
Goal: Submit official drawings that meet local building code.
✔️ Floor plans, elevations, and materials
✔️ May need licensed architect or designer
✔️ Include plumbing, electrical, and HVAC layouts
ADULink works with trusted professionals to create city-ready plans.
4️⃣ Submit for Permitting
Goal: Apply for a building permit with your city’s Inspectional Services or Building Department.
You’ll need to submit:
- Architectural drawings
- Site plan
- Energy compliance form (Massachusetts Stretch Code may apply)
- Permit application and fee
Processing time: 2 to 8 weeks, depending on the city
5️⃣ Plan Review & Corrections
City officials will review your plans to ensure they meet:
- Building code
- Zoning regulations
- Fire safety and egress rules
- Energy efficiency
They may request revisions. We help you respond quickly and stay on track.
6️⃣ Receive Building Permit
Once approved, you’ll receive your building permit — and you’re ready to break ground!
You’ll typically have 6 to 12 months to start construction once the permit is issued.
7️⃣ Inspections During Construction
Your city will inspect the ADU at key milestones:
- Foundation
- Framing
- Rough plumbing/electric
- Final walk-through
Pass all inspections and you’ll receive a Certificate of Occupancy — your ADU is now legally ready to use!
🛠️ Who Handles All This?
You can either:
- DIY (with lots of time, patience, and paperwork), or
- Work with a full-service ADU project manager like ADULink
We take care of everything — from zoning checks to final inspections.
📍 Massachusetts Cities We Serve
We’re active in over 40 cities and towns across the state — including Boston, Cambridge, Lowell, Worcester, Lynn, Revere, Salem, and more.
👉 Check your city’s ADU rules here »
💬 Final Thoughts
Permitting an ADU in Massachusetts has never been easier — but it still requires attention to detail.
At ADULink, we help you navigate every step of the process, so you can focus on what matters: building value, income, and space for the future.
📞 Ready to start your ADU journey?
👉 [Schedule a Free Consultation]
👉 [Find Out If Your Property Qualifies]