ADU Costs in Lynn, MA
Building an ADU in Lynn costs $135k–$315k depending on type, with up to 900 sq ft allowed.
Estimate ADU costs in Lynn, Massachusetts based on local size limits, allowed types, and zoning rules. Plan your budget with real data.
ADU Regulations in Lynn
Lynn follows the Massachusetts state baseline under the Affordable Homes Act. This means all Massachusetts state-level ADU rights apply — including by-right approval, no owner occupancy requirement, and standardized size limits. Lynn may also have additional local regulations that supplement the state baseline.
Cost by ADU Type in Lynn
ADU costs in Lynn vary by type:
- Conversion: $100–$200/sq ft — most affordable, reuses existing structure
- Attached: $150–$250/sq ft — shares a wall and utility connections with your home
- Detached: $200–$350/sq ft — most expensive, but offers maximum privacy and flexibility
Budget for a Full-Size ADU
With 900 sq ft allowed in Lynn, a maximum-size detached ADU could cost $180k-$315k for construction alone. Add 15-25% for permits, design, site work, and utility connections. A smaller footprint can significantly reduce costs.
Return on Investment
ADUs in Lynn can generate significant rental income while also increasing your property value. With a population of 101,253, Lynn has strong rental demand that supports competitive rates. Without owner occupancy requirements, you have full flexibility to maximize your rental returns — including the option to rent both units.
Lynn ADU Rules at a Glance
Max Size
900 sq ft
% of Home
50%
Max Height
35 ft
Front Setback
10 ft
Side Setback
8 ft
Rear Setback
15 ft
Parking
1 space(s)
Approval
BY RIGHT
Owner Occupancy
Not required
Rental Allowed
Yes
Short-Term Rental
Not allowed
Lynn Building Department
Frequently Asked Questions
How much does it cost to build an ADU in Lynn, MA?
ADU costs in Lynn typically range from $150,000 to $350,000+ depending on the type. With a maximum size of 900 sq ft allowed, a full detached ADU (the most expensive option) in Lynn could cost $200-$350/sq ft. Interior conversions are typically the most affordable at $100-$200/sq ft.
What is the cheapest type of ADU to build in Lynn?
In Lynn, a conversion ADU is typically the most affordable option. Interior conversions reuse your existing structure (basement, attic, or garage), eliminating foundation and framing costs. Lynn allows detached, attached, conversion ADUs, giving you flexibility to choose based on your budget.
Are there ADU financing options in Lynn?
Common ADU financing options available to Lynn homeowners include home equity loans (HELOCs), construction loans, cash-out refinancing, and renovation loans (FHA 203k or Fannie Mae HomeStyle). Some Massachusetts programs also offer ADU-specific financing or incentives.
What rental income can I expect from an ADU in Lynn?
ADU rental income in Lynn depends on size, finishes, and location. A full 900 sq ft unit (2-bedroom) can command premium rents. With a population of 101,253, Lynn has strong rental demand that supports competitive rates.
Do ADU permit fees add significantly to costs in Lynn?
Permit fees in Lynn typically range from $1,000 to $5,000 depending on the project scope. While not the biggest cost factor, budget for building permits, plan review fees, utility connection fees, and any impact fees. By-right approval in Lynn means you avoid the additional costs of hiring a lawyer for public hearings.
Where can I find all ADU regulations for Lynn?
Visit our complete ADU rules page for Lynn, MA for a full overview of zoning, permits, size limits, setbacks, parking, and costs. We cover all Massachusetts municipalities with data sourced from local ordinances and state law.
Check Your Address
See exactly what ADU rules apply to your specific property in Lynn.