The Complete BuildX ADU Build Process (From First Call to Move-In)

By Buz Artiano, BuildX | February 2026

Planning a major construction project creates anxiety for a lot of people. You want to know exactly what happens, when it happens, and what it will cost before you commit to anything or spend any money. Most ADU builders in Massachusetts keep their process vague, they don't tell you what things are going to cost or how long they will take upfront. That can definitely make some people hesitate, even when building an ADU is clearly the right decision.

We've built dozens of ADUs in Massachusetts and we've refined every step of our process to make sure there are no surprises and no stalls. We don't believe in empty promises and we know people need predictability more than anything.

At BuildX, we specialize in detached ADUs throughout Massachusetts, and our systematic way of doing things means we can offer you a 100-day build guarantee, but most of our projects actually take 80 to 85 days. This article walks you through every phase, from your first free consultation to moving in.

What Does the Complete BuildX Timeline Look Like?

The BuildX process has four phases: consultation, pre-development, permitting, and construction. Each one has certain goals and milestones, clear costs, and timelines you can count on. If you started today, you would likely move into your completed ADU in six to eight months.

Here's a breakdown of the timeline. Your free Zoom consultation happens within a couple of days from when you first contact us. Pre-development takes 45 to 90 days after signing. Permitting runs 90 to 120 days depending on your town, and construction takes 100 days or less from groundbreaking to move-in.

What Happens During Your First Consultation?

Your first meeting with BuildX is a free Zoom consultation. During this call, we use this special software called "Can I Build?" to show you in real time whether an ADU will fit on your property or not. That way you know if your project is even possible before you start investing any money.

Then we'll talk about what you want to build. Things like size, layout, and what you'll be using it for. Based on your answers, we'll give you a budget range so you can decide whether the project makes financial sense for you. Sometimes the numbers don't work, and we always tell you that honestly. If the budget is more than what you are comfortable with, we'll discuss options for bringing some of the costs down, but we'll also tell you if the project doesn't really make sense after a certain price point.

We also encourage you to come to one of our open houses so you can walk through a finished ADU. Seeing a finished unit in person is so much better than looking at plans on paper. Our customers are usually there as well, so you can ask them directly about their experience working with us.

What Does the Pre-Development Phase Include?

After your initial consultation, the next step is signing a pre-development agreement for $5,900. This is a flat fee that covers all the work we need to do to get you to a fixed-price contract. We also talk to and get on the schedule with a surveyor during this phase, which usually costs right around $4,000. But we credit that toward your final project cost if you decide to move forward with us.

During pre-development, we finalize your ADU design over the span of 2 or 3 meetings, either in person at our Carver office or over Zoom. We work on the design in real time, and show you 3D renderings so you can really start to visualize the space with furniture placement and outside appearance.

This is also when you will pick all of your finish selections such as roofing, siding, windows, doors, paint colors, flooring, cabinets, and fixtures. Picking all this stuff out at the very beginning is extremely important. The secret to a successful 100-day build is having everything decided before construction starts. There are no changes made to orders mid-project that cause delays.

We are also starting to communicate with your town during this phase. We call the local building department, water department, and other agencies to get answers to specific questions about your property. When we present your final proposal, all the information will be current and accurate, no guesses or estimates.

How Long Does Permitting Take in Massachusetts?

The permitting phase typically takes 90 to 120 days from start to building permit in hand. This process also contains several steps. First, we file for a zoning permit, then we complete the construction drawings and selections while we are waiting for zoning approval. Once zoning is approved, we finalize the price and file for the building permit.

Massachusetts has made a lot of this easier under the state ADU law. Applications are submitted online, and towns have 30 days to approve or deny. As everybody knows, bureaucratic delays can always happen, but our experience working with the local towns requirements help us avoid issues and common mistakes that can cause permits to be denied.

What Happens After You Sign the Construction Contract?

Once all documents are finished and you have your building permit, and we know exactly what we are building, you sign the fixed-price construction contract. The first payment on this contract is $25,000. All the following payments are made when work is completed, not on specified dates. When you can look out your window and see the foundation is installed, then you pay. Same thing goes for the framing and the roof. Mechanicals like HVAC equipment are done and signed off before you pay as well. We'll never ask you to pay for work that hasn't been done.

The day you sign the contract, we order everything: windows, doors, roofing, siding, framing materials, electrical wiring, plumbing fixtures, and cabinets. The only things we can't order in advance are insulation and drywall. We always order materials immediately so we can lock in the current price and so we know everything will be ready when we get to each phase. Our suppliers already know to hold materials for us until we need them.

At this point, you also meet your dedicated project manager. This person has been involved in your pre-construction meetings and knows your specific project inside and out. They will be your main contact from the time you sign the contract until you move-in. But you still always have access to our office and to our team. You'll never be without a direct line to someone who knows you and your project.

How Long Will Your Construction Take?

We guarantee a 100-day build from the day we start digging to move-in. If something specific about your property is going to make that take longer, such as a complicated septic system or a water department requirement that adds two weeks, we tell you all of that before you sign the contract. We might say your project will take 110 days instead of 100, but we will explain to you exactly why. But it's never going to be something like 200 days. The longest any of our projects has ever taken is 120 days. Most of them are finished in 80 to 85 days.

We just finished a project in Freetown that only took 82 days. The reason we can consistently stay in that time frame is because we stick-build on site using proven methods, we order all materials upfront, and make every design decision before breaking ground.

During construction, you can see everything that's happening on your project. The first thing we do when starting a job is install a four-headed site camera with cell connection and night vision. You get your own login and can check on the job site from your phone or laptop anytime you want. You also get access to our Job Tread portal, which shows you the construction schedule and progress updates.

What Happens After Construction Is Complete?

Before you move in, your ADU goes through several inspections like plumbing, electrical, HVAC, septic (if applicable), building inspector, and fire department. After those are all signed off, we'll get rid of the construction dumpster, clean the site, and do your final walkthrough with you.

During the walkthrough, we'll give you a rundown on all the systems, show you where the air filters are, and explain any maintenance you will need to do. We then provide you with a three-year warranty.

After 11 months, we come back for a scheduled follow-up visit. New construction goes through settling as it goes through its first year of heating and cooling. You can get small cracks in the drywall, which is totally normal. So we come back, caulk the baseboards, touch up any cracks, and deal with any minor issues that come up in a new structure. You don't have to chase us down for warranty work, we will come to you, it's part of our process.

Is the BuildX Process Right for Every Homeowner?

Our process works best for people who really want predictability and are ready to make decisions upfront. If you think you'd rather figure things out as you go, change your mind frequently during construction, or want to find and purchase your own materials to save money, our system may not give you the freedom you need. The pre-development phase requires you to commit to all your selections before construction even starts. This is how we are able to be true to our timeline and fixed pricing.

There's a couple kinds of people who just don't do well with our approach and methods. The ones who want a lot of flexibility during construction to change finishes, layouts, or materials as they see the project moving along. Or the ones who want to act as their own general contractor and manage subcontractors themselves to save money. If you think you fall under one of those two categories, then maybe a custom builder or owner-builder way of doing things is better for you than our standardized process.

For homeowners who want to know exactly what they are getting, when they are getting it, and what it will cost. Our way of doing things takes away the stress and uncertainty that you get with so many construction projects.

Ready to See If Your Property Qualifies?

The best way to understand our process is to go through the first step. If you want to see what a finished BuildX ADU looks like, ask about our upcoming open house events where you can walk through completed projects and talk with actual customers.