Cape Cod's Trusted ADU Builder | 20+ Years Experience
We don’t build to code, we build to exceed expectations. Building code defines what is legally acceptable. It does not define excellence.
- Workmanship guarantee
- ADUs now legal by-right in Massachusetts, no special permit or public hearing needed
- 20+ years building on Cape Cod
- Transparent, line-item pricing, no surprise change orders
5.0
Nick McElroy
Customer feedback
We work closely with Mussato Building Group on high end residential projects, and they are consistently excellent to collaborate with. Joe’s attention to detail is second to none, and it shows in every aspect of the homes he builds. He truly crafts beautiful custom homes, not just houses.
Joe is a great listener, highly organized, and always shows up for the client and the project. His expectations are clear, his communication is solid, and he takes pride in delivering a finished product that exceeds standards. We highly recommend Mussato Building Group to anyone looking for a true custom home builder.
Book Your FREE ADU Consultation and Get A Site Feasibility Report
BOOK YOUR FREE ADU CONSULTATION THIS WEEK & GET A SITE FEASIBILITY REPORT. KNOW EXACTLY WHAT YOU CAN BUILD BEFORE YOU SPEND A DOLLAR.
About Us
We are a family owned and operated company located in Cape Cod, MA. With more than 20 years of experience, the company has established itself in the construction industry, primarily servicing clients within Cape Cod area.
Mussato Building Group Inc. is known for its commitment to integrity, personal attention, superior craftsmanship, and efficient communication.
Client Testimonials
Hear directly from homeowners who trusted us to build and enhance their homes. Their stories underscore our dedication to excellence, reliability, and personalized attention.
What Sets Us Apart
Licensed & Fully Insured
Every project is fully permitted and insured up to $1M. You'll never worry about liability, code violations, or unfinished work. We handle all permit paperwork so you don't have to.
22+ Years of Experience
Joe Mussato brings over two decades of hands-on residential construction experience. They've seen every challenge Cape Cod homes can throw at them and they know exactly how to solve it.
On-Time, On-Budget Delivery
We set realistic timelines and we stick to them. No vague promises, no disappearing for weeks. You'll get a clear schedule before any work begins — and we'll keep you updated at every stage.
Transparent, Line-Item Pricing
You'll see exactly where every dollar goes before signing anything. No hidden fees, no surprise change orders, no uncomfortable conversations at the end. The price we quote is the price you pay.
Hands-On Leadership
Joe don't sit in an office. he's on your job site, managing crews, solving problems in real time, and making sure every detail meets their personal standard. You'll always know who's in charge of your project.
Cape Cod Expertise
Older Cape Cod homes come with unique challenges — historic district, tight spaces, outdated plumbing, moisture from salt air, and quirky layouts. We specialize in working with these homes, not against them. We know what works here because we've been doing it here for years.
Is Your Property Ready?
- You own a single-family home on Cape Cod with unused yard or lot space
- You have a detached garage or outbuilding that could be converted
- You're paying a mortgage on land that's generating zero income
- You assumed building a second unit wasn't allowed and haven't checked since the law changed
Our Process
1
Free Consultation & Site Feasibility Report
Joe or a senior team member visits your property to evaluate the lot, setbacks, zoning, septic capacity, utility access, terrain, and existing structures. You’ll receive a Site Feasibility Report that tells you exactly what you can build, where it can go, and what to expect. No cost. No commitment.
2
Design & Budget
We design your ADU around your goals, rental income, family housing, or long-term value. You’ll see floor plans, exterior elevations, and material options alongside a detailed line-item budget. We adjust until the design and the investment feel exactly right.
3
Permitting
We prepare and submit your building permit application, coordinate septic review, and manage any additional approvals. Since ADUs are now by-right in Massachusetts, the standard process moves faster, but we still make sure every document is airtight.
4
Site Work & Foundation
Clearing, grading, utility connections, septic (if separate system required), and foundation. Every step inspected and built to Cape Cod’s specific soil and frost requirements.
5
Construction — Frame to Finish
Framing, roofing, siding, windows, plumbing, electrical, HVAC, insulation, drywall, cabinetry, tile, flooring, painting, trim, fixtures. Joe and his crew manage every trade on site. You’ll receive regular updates at every milestone.
6
Final Inspections, Walkthrough & Handoff
We coordinate all required inspections and obtain your certificate of occupancy. Then we walk every inch with you, every finish, every fixture, every system. We don’t hand over the keys until you’re 100% satisfied. Your property is left cleaner than we found it.
Types of ADUs We Offer
Detached Guest Cottage
A standalone structure in your backyard, fully independent with its own entrance, kitchen, bathroom, bedroom, and living space. The most popular ADU type on Cape Cod. Ideal for vacation rentals, family housing, or a private guest suite. We design exteriors that complement your primary home so it looks like it was always there.
Garage Conversion
Already have a detached garage you barely use? Converting it into a livable ADU is one of the most cost-effective options, the structure, foundation, and roof already exist. We handle insulation, plumbing, electrical, interior buildout, and any structural upgrades needed to meet code.
Above-Garage Unit
Build upward instead of outward. A second-story addition above your existing garage creates a fully independent apartment without using any additional ground space. Perfect for smaller lots or properties with tight setback requirements.
Attached In-Law Suite
An addition connected to your primary home but with its own private entrance, kitchen, and bathroom. Ideal for aging parents who want independence but the security of being steps away. Designed for accessibility, wider doorways, curbless showers, single-floor living — when needed.
Pre-Fab ADU
A factory-built accessory dwelling unit delivered to your property and set in place with speed and precision. Pre-fab ADUs reduce construction time while maintaining high-quality finishes and full functionality, including kitchen, bathroom, bedroom, and living space. Ideal for homeowners looking for a faster, more streamlined build process with predictable costs. We handle site work, foundation, utilities, delivery coordination, and final installation, ensuring the unit integrates seamlessly with your property and meets all local codes.
Frequently Asked Questions
Is it really legal to build an ADU on my property now?
Yes. Under the 2024 Massachusetts Affordable Homes Act, every single-family homeowner can build one ADU up to 900 sq ft (or 50% of the primary home’s floor area, whichever is smaller) by-right. No special permit, no zoning variance, no public hearing. You still need a standard building permit and code compliance which we handle for you.
How much does it cost to build an ADU on Cape Cod?
Most ADU projects on the Cape range from $150,000 to $350,000+ depending on size, finishes, site conditions, and whether it’s a new build, garage conversion, or above-garage unit. We provide a detailed, line-item proposal so you know exactly where every dollar goes before committing.
How much rental income can an ADU generate?
Depends on location, size, and rental strategy. Seasonal vacation rentals on Cape Cod typically generate $25,000 to $60,000+ per year. Year-round rentals can generate $1,500 to $3,000+ per month. An ADU built for rental performance which is exactly what we specialize in, can often pay for itself within 4 to 7 years.
Will I need to upgrade my septic system?
Possibly. Since an ADU typically adds a bedroom, your septic system must be rated for that increased capacity. In nitrogen-sensitive areas of Cape Cod, an Innovative/Alternative (I/A) system may be required, adding $20,000 to $30,000. We evaluate your septic situation in our free Site Feasibility Report before you spend anything.
How long does it take to build?
Most ADU projects take 4 to 8 months from permit to move-in. Garage conversions are typically faster (3-5 months). New detached builds take longer depending on site work and complexity. We provide a realistic timeline during the design phase and stick to it.
Will an ADU increase my property taxes?
Generally yes, an ADU is an improvement that increases your property’s assessed value. However, the tax increase is typically modest compared to the rental income or equity gained. Many Cape Cod towns are also exploring tax incentives for ADUs rented year-round to local residents.
Can I use the ADU for Airbnb / vacation rental?
In most Cape Cod towns, yes, but short-term rental regulations vary by municipality. Some towns require registration or limit the number of rental days. We can help you understand your specific town’s rules during the consultation so you build with the right rental strategy in mind.
What if my lot is small or has challenging terrain?
That’s exactly what our Site Feasibility Report evaluates. Many Cape Cod lots that look too small or complex actually qualify, it’s a matter of knowing the setback rules, septic options, and creative design solutions. We’ve built on tight lots, sloped lots, and wooded lots. Let us assess yours before you assume it won’t work.
What materials do you recommend for Cape Cod kitchens?
We handle everything, frame to finish. Design, permitting, site work, foundation, framing, plumbing, electrical, insulation, interior finish, exterior finish. One team, one contract, one point of contact. You don’t need to hire anyone else.
What makes Mussato different from other ADU builders?
Joe’s carpentry and finish work has been called “unmatched” by clients who’ve hired dozens of contractors. You’re not getting a generic builder. You’re getting a craftsman with 20 years of Cape Cod-specific experience.
BOOK YOUR FREE ADU CONSULTATION THIS WEEK & GET A SITE FEASIBILITY REPORT. KNOW EXACTLY WHAT YOU CAN BUILD BEFORE YOU SPEND A DOLLAR.
Book Your FREE ADU Consultation and Get A Site Feasibility Report
Find Out What You Can Build, For Free
The first step isn’t signing a contract. It’s knowing what’s possible on your specific lot.
Our free Site Feasibility Report gives you the answer, zoning, setbacks, septic, and build potential, before you spend a dollar.
- Free site visit and feasibility analysis
- Zoning, setbacks, septic capacity, and buildability evaluated
- Honest answer on what you can and can't build
- If it's buildable: design options, timeline, and line-item pricing
- Our team will respond within 24 hours