From Dream to Done: The Real Process of Building an ADU in Massachusetts

You know what question I get more than almost anything else? “Dan, I love the idea of an ADU, but what does this actually look like from start to finish?” Fair question. Building an Accessory Dwelling Unit isn’t like ordering furniture online – it’s a real construction project with permits, inspections, and more moving parts than your average IKEA assembly.

But here’s the good news: when you understand the process, it’s way less intimidating. At Conway Home Remodeling, we’ve guided countless Massachusetts homeowners through ADU builds, and I’m going to walk you through exactly how it happens. No fluff, no surprises – just the honest truth about what to expect.

Step One: The “Is This Even Possible?” Conversation

Before we break ground on anything, we need to figure out if an ADU makes sense for your property. This isn’t about crushing dreams – it’s about being smart and realistic from day one.

We start with a site visit to your home. I’ll walk your property with you, measuring, observing, asking questions. How much yard space do you have? Where are your utility connections? What’s the slope situation? Is there good access for construction equipment?

Then comes the fun part: checking your local zoning regulations. And let me tell you, Massachusetts towns have some opinions about ADUs. Some communities rolled out the welcome mat with recent zoning changes, while others still have restrictions that make things tricky. Boston, Cambridge, Somerville, Newton – they’ve all got different rules about lot size, setbacks, parking requirements, and maximum ADU square footage.

I’ve seen properties where we thought an ADU was impossible until we found a creative solution, and I’ve seen “perfect” lots that turned out to have zoning restrictions we couldn’t work around. That’s why this step matters – we’re making sure your time, money, and hopes are invested wisely.

Step Two: Design and Vision

Once we know an ADU is feasible, the real fun begins. This is where your vision meets our experience, and we figure out exactly what we’re building.

Some clients come to us with Pinterest boards and detailed sketches. Others just know they need “a space for Mom” or “something we can rent out.” Both approaches work – we’re here to translate your needs into actual blueprints.

We’ll discuss size (Massachusetts ADUs typically range from 500-1200 square feet), layout (studio, one-bedroom, or two-bedroom), and style (should it match your main house or have its own character?). We’ll talk about practical stuff like whether you need accessibility features, how much natural light you want, and what finishes make sense for your budget.

This is also when we have the money conversation. Nobody likes talking budgets, but I’d rather surprise you with how much we can do for your investment than hit you with unexpected costs down the road. We’ll break down options – where you can splurge, where you can save, and what gives you the best return on investment.

Step Three: Engineering and Permitting (The Patience Phase)

Okay, I won’t sugarcoat it – this phase isn’t the most exciting, but it’s absolutely crucial. This is where we take your design and get it approved by all the right people.

First, we bring in engineers and architects to create detailed construction drawings. These aren’t the fun “here’s what your ADU will look like” renderings (though we have those too). These are the technical plans that show exactly how we’re building this thing to code, how utilities will connect, and how the structure will be safe and sound for decades.

Then we head into the permit process. In Massachusetts, this typically involves your local building department, the health department (for septic or sewer connections), and sometimes the zoning board if we need any variances or special permits. We submit plans, answer questions, make revisions, and eventually get that golden approval to build.

How long does this take? Honestly, it varies by town. Some communities move fast and we’re approved in 4-6 weeks. Others take 3-4 months. We stay on top of it, following up regularly and addressing any concerns quickly, but there’s always some waiting involved. Think of it like the DMV – but for building your dream ADU.

Step Four: Site Prep and Foundation

Finally! This is when things start looking real. Once permits are in hand, we mobilize our crew and get to work.

First up: site preparation. We’ll clear and grade the building area, set up temporary utilities for construction, and establish access routes. If you’re keeping your yard intact, we’ll protect it with fencing and ground protection. We’ve built ADUs in backyards where the only access was through a narrow side yard, and we’ve done it without destroying the landscaping. It just takes planning and care.

Then we pour the foundation. Depending on your soil conditions, zoning requirements, and design, this might be a slab-on-grade, a crawl space, or even a full basement (though that’s less common for ADUs). This phase typically takes 1-2 weeks, and it’s weather-dependent – we need decent conditions for concrete work.

Pro tip: This is when your neighbors start noticing what’s happening. We’re respectful about noise, timing, and keeping the site clean, but there’s no hiding a construction project. A quick heads-up to your neighbors goes a long way.

Step Five: Framing and Exterior

Once the foundation cures, framing begins. This is the phase everyone loves because your ADU suddenly looks like an actual building. Walls go up, the roof takes shape, windows and doors get installed – you can finally walk through and visualize the space.

We frame with quality lumber, install proper insulation, and make sure everything is square, plumb, and built to last. Massachusetts weather is no joke, so we’re paying close attention to weatherproofing and energy efficiency from day one.

The exterior comes together next: siding, roofing, trim work. This is where your ADU starts developing personality. Whether we’re matching your main house’s aesthetic or creating something with its own character, we’re focused on quality materials and craftsmanship that’ll hold up to New England’s weather extremes.

This phase typically runs 4-6 weeks, depending on size and complexity. You’ll see steady progress, and it’s incredibly satisfying.

Step Six: Utilities and Systems

While the exterior is wrapping up, we’re roughing in all the behind-the-walls systems: plumbing, electrical, HVAC. This is technical, unglamorous work that you’ll never see – but it’s what makes your ADU actually livable.

We’re running water lines, installing drain systems, connecting to your sewer or septic. We’re wiring for outlets, switches, lighting, and internet. We’re setting up heating and cooling systems sized appropriately for the space. In Massachusetts, we’re also making sure everything exceeds energy code requirements – because high utility bills are nobody’s friend.

Each system gets inspected by the town as we go. Rough plumbing inspection, electrical inspection, insulation inspection – it’s a process, but it ensures everything is done right and up to code.

Step Seven: Interior Finishes

This is where your ADU transforms from construction site to actual home. Drywall goes up, painting happens, flooring gets installed. Kitchens and bathrooms come together with cabinets, countertops, fixtures, and tile work.

We’ll install the trim, hang interior doors, and add all those finishing touches that make a space feel polished and complete. Lighting fixtures, hardware, shelving – every detail matters.

This is also when you’ll make final decisions on finishes if you haven’t already. What color paint? Which cabinet hardware? What style light fixtures? We guide you through these choices, offering options at different price points and helping you create a cohesive look.

The interior finish phase typically takes 3-4 weeks, and it’s honestly the most rewarding part. You’re watching your vision become reality, and every day brings new progress.

Step Eight: Final Inspections and Certificate of Occupancy

We’re in the home stretch! Once construction is complete, the town comes back for final inspections. Building inspector checks overall construction quality and code compliance. Fire inspector verifies smoke detectors, egress windows, and fire safety requirements. Health inspector signs off on plumbing and septic connections.

If everything passes (and with our experience, it usually does on the first try), the town issues a Certificate of Occupancy. This is the official document saying your ADU is safe, legal, and ready to be occupied.

No CO, no moving in – Massachusetts doesn’t mess around with this. But once you’ve got it, you’re golden.

Step Nine: Finishing Touches and Handover

Before we hand you the keys, we do a final walkthrough together. We’ll demonstrate how everything works, provide you with warranty information and maintenance guidelines, and address any last-minute touch-ups or adjustments.

We’ll also provide you with all the documentation you need: as-built plans, equipment manuals, warranty information, and that precious Certificate of Occupancy. Keep these safe – you’ll need them for insurance, future maintenance, and eventual resale.

What Makes Conway Different

Here’s what I want you to know: we don’t disappear between phases. You’re not calling around trying to figure out where your project stands or who’s responsible for what. We manage the entire process from concept to completion – one team, one point of contact, one accountability.

We’ve built relationships with local building departments across Massachusetts. We know what they’re looking for, what questions they’ll ask, and how to get approvals efficiently. We’ve got trusted subcontractors for specialized work, and we coordinate everything so you don’t have to.

Most importantly, we communicate. You’ll know what’s happening, what’s next, and if anything changes. No surprises, no excuses – just honest, professional service from people who’ve done this many times before.

Ready to Start Your ADU Journey?

Look, building an ADU is a commitment. It takes time, investment, and patience. But when it’s done, you’ve got a beautiful, functional space that solves real problems in your life – whether that’s housing family, generating income, or just giving you flexibility for whatever comes next.

The process isn’t as scary as it might seem, especially when you’re working with a team that’s guided dozens of Massachusetts homeowners through it successfully. We know the challenges, we’ve solved the problems, and we’re ready to help you make it happen.

If you’re serious about building an ADU, let’s sit down and talk through your specific situation. We’ll tour your property, discuss your goals, and map out exactly what your project would look like from start to finish. No pressure, no sales pitch – just honest expertise from a team that genuinely loves making these projects work.

At Conway Home Remodeling, we’re not just building ADUs – we’re helping Massachusetts families create solutions that make their lives better. And that’s a process worth getting right.