Massachusetts' Leading ADU Experts

Transform your property with a custom Accessory Dwelling Unit. Mass ADU provides complete architectural planning, permitting, engineering, and construction services across Massachusetts.

From initial design to final inspection, we handle every aspect of your ADU project. Whether you're looking to create rental income, house family members, or increase property value, our experienced team makes the process simple and stress-free.

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Modern ADU exterior design showing contemporary architecture

Complete ADU Services for Massachusetts Homeowners

Mass ADU is your trusted partner for Accessory Dwelling Unit development across Massachusetts. We provide end-to-end services that transform your property into a valuable investment while navigating complex local regulations with expertise.

Architectural Planning

Our licensed architects create custom ADU designs tailored to your property, lifestyle, and local zoning requirements. From concept to construction-ready plans, we ensure your vision becomes reality.

Permitting Services

Navigate Massachusetts' complex permitting process with confidence. We handle zoning applications, building permits, utility connections, and all required approvals to keep your project on track.

Engineering

Our licensed engineers ensure structural integrity, utility systems, and code compliance for your ADU. We handle foundation design, load calculations, and all technical requirements.

Construction

Licensed builders bring your ADU to life with quality craftsmanship. We coordinate all trades, manage schedules, and ensure your project is completed on time and within budget.

Why Choose Mass ADU?

Local Expertise

Deep knowledge of Massachusetts regulations and building codes across all municipalities.

Full-Service Solution

One team handles everything from design through construction completion.

Licensed Professionals

All services provided by licensed architects, engineers, and contractors.

Proven Track Record

Hundreds of successful ADU projects completed.

Beautiful ADU interior showing open floor plan design

Ready to Start Your ADU Project?

Get a free consultation and discover how an ADU can transform your property into a valuable investment.

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Massachusetts ADU Regulations & Requirements

Understanding Massachusetts ADU regulations is crucial for a successful project. Our team stays current with all state and local requirements to ensure your ADU complies with all applicable laws.

Zoning Requirements

  • Allowed in most residential zones
  • Size typically limited to 50-100% of main house
  • Setback requirements vary by municipality
  • Height restrictions apply
  • Lot coverage limits must be met

Owner Occupancy

  • Owner must live on property
  • Can live in main house or ADU
  • Some exceptions for family members
  • Rules vary by municipality
  • Deed restrictions may apply

Parking Requirements

  • Typically 1-2 additional spaces required
  • May be reduced near public transit
  • Tandem parking sometimes allowed
  • ADA accessibility may be required
  • Bicycle parking encouraged

Building Code Compliance

  • Must meet state building codes
  • Separate entrance required
  • Kitchen and bathroom mandatory
  • Ceiling height minimums
  • Emergency egress requirements

Municipal Variations Across Massachusetts

Boston

Allows ADUs in most residential districts. Size limited to 900 sq ft or smaller of the two units. Owner occupancy required.

Cambridge

Progressive ADU policies with reduced parking requirements near transit. Size limits based on lot size and main house.

Worcester

Allows ADUs with special permits. Specific design standards for neighborhood compatibility required.

Important: ADU regulations vary significantly between Massachusetts municipalities. Our team researches current requirements for your specific location and ensures full compliance throughout the process.

Massachusetts Service Areas

Mass ADU proudly serves communities across the Commonwealth, bringing expert ADU construction and design services to homeowners throughout Massachusetts. From bustling Boston to charming coastal towns, we're here to help you transform your property.

36+ Cities Served • Full-Service ADU Solutions
Greater Boston Area
Premium Urban Markets
Boston
Cambridge
Somerville
Brookline
Newton
Quincy
North Shore
Coastal Communities
Salem
Lynn
Peabody
Beverly
Gloucester
Newburyport
South Shore
Historic Coastal Towns
Plymouth
Braintree
Weymouth
Hingham
Scituate
Marshfield
MetroWest
Suburban Excellence
Framingham
Natick
Wellesley
Waltham
Watertown
Marlborough
Central Massachusetts
Growing Communities
Worcester
Fitchburg
Leominster
Milford
Shrewsbury
Westborough
Western Massachusetts
Pioneer Valley & Beyond
Springfield
Holyoke
Chicopee
Westfield
Amherst
Northampton

Don't See Your City Listed?

We serve communities throughout Massachusetts. Contact us to discuss your specific location and learn about our comprehensive ADU services in your area.

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500+ Projects Completed

Expert ADU Insights & Guides

Stay informed with the latest ADU trends, regulations, and construction insights specifically for Massachusetts homeowners.

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Frequently Asked Questions

Get answers to the most common questions about ADU development in Massachusetts. Our comprehensive FAQ covers everything from regulations to costs and timelines.

Types of ADUs

In Massachusetts, you can build several types of ADUs including detached ADUs (separate structures), attached ADUs (connected to main house), garage conversions, basement conversions, and attic conversions. Each type has specific requirements based on local zoning laws and building codes.

A detached ADU is a separate, standalone dwelling unit on the same property as your primary residence. These can be built as new construction or converted from existing structures like garages or workshops.

Yes, garage conversions are popular ADU options in Massachusetts. We handle all aspects including structural modifications, electrical, plumbing, insulation, and permit acquisition to transform your garage into a livable space.

An attached ADU is connected to your main house but has its own separate entrance, kitchen, bathroom, and living space. These are often created by converting existing space or adding onto your home.

Yes, basement conversions are permitted in many Massachusetts municipalities, provided they meet ceiling height requirements, egress requirements, and other building code standards for habitable space.

Attic conversions are possible if the space meets minimum ceiling height requirements and proper egress can be installed. We assess structural capacity and building code compliance for all attic ADU projects.

ADU Benefits

ADUs provide rental income potential, increase property value, offer housing for family members, create flexible living space, and help address Massachusetts' housing shortage while maintaining neighborhood character.

ADU rental income in Massachusetts typically ranges from $1,200-$3,000+ per month depending on location, size, and amenities. Urban areas like Boston, Cambridge, and Somerville command higher rents.

Yes, ADUs typically increase property value by 15-25% or more, often exceeding the construction cost. They're considered a valuable addition that enhances marketability and investment potential.

Absolutely! Many homeowners build ADUs to house aging parents, adult children, or as guest accommodations. This provides independence while keeping family close.

ADUs are excellent for retirement planning, providing rental income and the option to downsize by moving into the ADU while renting out the main house.

ADUs increase housing density without changing neighborhood character, providing affordable housing options and helping Massachusetts address its housing crisis sustainably.

Services Offered

We offer complete ADU services including architectural design, engineering, permit acquisition, zoning consultation, construction management, and ongoing support throughout your ADU project.

Yes, we manage the entire permitting process including zoning applications, building permits, utility connections, and all required inspections. Our team knows Massachusetts regulations inside and out.

Our licensed architects create custom ADU designs tailored to your property, needs, and local requirements. We handle everything from initial concepts to construction-ready plans.

Our licensed engineers provide structural analysis, foundation design, utility planning, and ensure all systems meet Massachusetts building codes and safety standards.

Yes, we provide full construction management with licensed builders, coordinating all trades, materials, schedules, and quality control to deliver your ADU on time and budget.

We provide expert consultation on zoning compliance, design options, cost analysis, and feasibility studies to help you make informed decisions about your ADU project.

Cost Factors and Timelines

ADU costs in Massachusetts typically range from $150,000-$400,000+ depending on size, complexity, site conditions, and finishes. We provide detailed cost estimates based on your specific project requirements.

Key cost factors include size, foundation requirements, utility connections, site access, permit fees, design complexity, material selections, and local labor rates. Site conditions significantly impact costs.

Total timeline is typically 8-18 months including design (2-3 months), permitting (3-6 months), and construction (3-9 months). Timelines vary based on project complexity and local approval processes.

Permitting in Massachusetts typically takes 3-6 months, varying by municipality. We expedite the process with complete, code-compliant submissions and ongoing coordination with local officials.

ADU financing options include home equity loans, construction loans, cash-out refinancing, personal loans, and specialized ADU lending programs. We can connect you with financing partners.

Some Massachusetts municipalities offer ADU incentives including reduced fees, expedited permitting, or grants. We stay current on available programs and help you take advantage of opportunities.

Permitting and Zoning

Massachusetts zoning for ADUs varies by municipality but generally includes setback requirements, size limitations (often 50-100% of main house), parking requirements, and owner-occupancy rules. We navigate all local requirements.

Most Massachusetts municipalities require owner-occupancy of either the main house or ADU. This means you must live on the property, but you can choose which unit to occupy.

ADU size limits in Massachusetts typically range from 500-1,200 square feet or 50-100% of the main house size, depending on local zoning. We design within your municipality's specific requirements.

Most areas require 1-2 additional parking spaces for ADUs. Requirements vary by location and proximity to public transit. We help you understand and meet local parking requirements.

Setback requirements vary but typically range from 5-20 feet from property lines. Corner lots and other special situations may have different requirements. We ensure compliance with all setback rules.

Most Massachusetts municipalities allow ADUs, but regulations vary significantly. Some have more restrictive rules than others. We research local ordinances and guide you through the specific requirements in your area.

ADU construction typically requires building permits, electrical permits, plumbing permits, and sometimes special use permits or zoning variances. We handle all required permits and approvals.

ADUs can have separate utility meters or share utilities with the main house. We coordinate with utility companies for connections and help you choose the most cost-effective approach.

Massachusetts Regulations

Massachusetts encourages ADU development through various state initiatives and requires municipalities to allow ADUs in residential zones, though local regulations still apply. The state promotes ADUs as a housing solution.

Most residential zones in Massachusetts allow ADUs, but specific regulations vary by municipality. Single-family residential zones typically have the most permissive ADU rules.

ADUs must meet Massachusetts building code including structural, electrical, plumbing, mechanical, and energy efficiency standards. They must have separate entrances and meet habitability requirements.

ADUs typically receive separate address designations for emergency services and mail delivery. We coordinate with local authorities to establish proper addressing for your ADU.

New ADU construction must meet ADA accessibility guidelines including doorway widths, bathroom accessibility, and may require accessible routes depending on local requirements.

Many municipalities have design standards requiring ADUs to be compatible with neighborhood character, including architectural style, materials, and landscaping requirements.

General Questions

Start by calling (323) 591-3717 for a free consultation or get an instant quote at start.gatheradu.com?ref=massachusetts. We'll assess your property, discuss your goals, and create a customized plan.

Yes, Mass ADU serves all Massachusetts municipalities. Our team understands the varying local regulations and has experience with permits across the state.

Yes! We have a portfolio of completed ADU projects across Massachusetts. Contact us to schedule a consultation where we can show you examples and discuss your specific needs.

We're the only true full-service ADU specialist in Massachusetts, handling everything from initial design through construction completion. Our expertise in local regulations and streamlined process sets us apart.

Yes, we provide comprehensive warranties on our construction work and use licensed professionals for all services. We stand behind our quality and craftsmanship.

While we focus on design and construction, we can refer you to trusted property management partners who specialize in ADU rentals to help maximize your investment return.

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Expert ADU Insights & Guides

Stay informed with the latest ADU trends, regulations, and construction insights specifically for Massachusetts homeowners.

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Join Our Team

Be part of Massachusetts' leading ADU development team. We're looking for talented professionals who share our passion for creating innovative housing solutions.

Architectural Designer

Join our design team creating innovative ADU solutions across Massachusetts. Requirements include architectural degree, CAD proficiency, and knowledge of Massachusetts building codes.

Requirements:
  • Bachelor's degree in Architecture or related field
  • Proficiency in AutoCAD, Revit, and SketchUp
  • Knowledge of Massachusetts building codes
  • 2+ years residential design experience
  • Strong communication and project management skills
Apply Now

Licensed Engineer

Lead structural engineering for ADU projects statewide. Requires PE license in Massachusetts and experience with residential construction.

Requirements:
  • Professional Engineer (PE) license in Massachusetts
  • Structural engineering experience
  • Residential construction background
  • Building code expertise
  • Project management experience
Apply Now

Construction Project Manager

Oversee ADU construction from groundbreaking to completion. Manage subcontractors, schedules, and quality control across multiple projects.

Requirements:
  • Construction management degree or equivalent experience
  • 5+ years residential construction management
  • Massachusetts contractor license preferred
  • Strong organizational and communication skills
  • Experience with residential permitting process
Apply Now

Why Work at Mass ADU?

Growth Opportunities

Advance your career in the rapidly expanding ADU industry

Collaborative Team

Work with experienced professionals across all disciplines

Meaningful Work

Help solve Massachusetts' housing challenges with innovative solutions

Transform Your Property with a Custom ADU

Join hundreds of satisfied Massachusetts homeowners who have increased their property value and created additional income with professionally designed and built ADUs.

From initial consultation to final inspection, Mass ADU handles every aspect of your project with expertise, transparency, and unmatched customer service.

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