BuildX's 100-Day ADU Build Guarantee: What It Covers and What Can Extend It

By Buz Artiano, BuildX | February 2026

When homeowners first come to us, one of their biggest fears is how long the whole project might take. They've heard horror stories about construction projects dragging on for eight months to a year, and in some cases even longer. They are thinking about how long their backyard will be torn up, or interest payments piling up on money they can't use, and then the constant stress of just not knowing when the whole thing will finally be done.

Trust us, we understand that time is money, literally. For every extra month that your ADU is not complete, that is another month you are paying interest on your loan while not being able to use your ADU for how it is needed. We plan out the entire construction process around these timeline issues.

At BuildX, we have built dozens of ADUs across Massachusetts, and the way we do things is much different than other construction companies. Under Massachusetts ADU regulations, ADUs are now allowed by right in single-family zoning districts, so the market is exploding. Most ADU builders take six to twelve months from the time they start the actual construction all the way to completion. We don't just hope for quick builds, we guarantee them. Here is how our 100-day build guarantee actually works, what can extend it, and why most of our projects finish even faster.

Does BuildX Really Guarantee 100 Days?

Yes, we guarantee a 100-day build from the day we start digging. That means from the day we break ground, you will be able to move into your completed ADU within 100 days. Most importantly, that number is not an estimate, it's a guarantee.

When Lieutenant Governor Kim Driscoll visited one of our project sites and learned how quickly we get these projects done, she called it "phenomenal" and said she wished all construction projects could do the same. Which is exactly what we hear from most homeowners. They expect construction to just drag on and on, but we prove it doesn't have to.

Our track record says it all. We recently completed a project in Freetown in just 82 days. That is the same with most of our builds, they almost always fall in the 80 to 85 day range, so we come in well under the 100-day guarantee.

What Could Extend the Timeline Beyond 100 Days?

There are some properties that have conditions that make a 100-day build impractical. But we look at all these factors in the very beginning and give you all the details before you sign the contract, long before the construction begins.

Things that can cause a build to take a little longer:

Complex septic systems: If your property requires a lot of septic work or coordination with health departments, we factor in that time upfront.

Challenging site access: Very long driveways or difficult to access properties can add time to certain phases of work.

Ledge or rock in the ground: If we find that there is ledge underground, the excavation takes longer than with normal soil conditions.

Steep slopes: Building on a steep slope means we have to do extra foundation work and site prep.

Utility coordination: If the water or power companies tell us they need two weeks to complete their part, we add that to your quoted timeline from the start.

If any of these are true for your project, we might tell you that it will take 110, 120, or even 130 days, but the longest build we have ever done took 120 days, and we explained everything before having them sign their contract. There are no surprises, no midstream revelations, and no "we did not realize" conversations.

Why Does the 100-Day Guarantee Matter Financially?

The amount of time a project takes directly affects your finances. Most ADU projects involve financing, probably with a HELOC (home equity line of credit), construction loan, or other type of loan. Once you start using the funds, you pay interest every day the project is under construction.

Think about it this way: if a cheaper builder quotes you a lower price but takes three extra months to complete the ADU, then you are paying interest on money you can't even use for another 90 days. That interest cuts right into the savings and a lot of time you actually lose money. Plus, you lose three months of using the ADU.

Our 100-day guarantee is not just about speed, it's about protecting your investment and creating an asset that you can use as soon as possible.

How Does BuildX Deliver on This Guarantee?

The secret to our quick builds is not a result of cutting corners. It is simply very meticulous pre-construction planning. By the time we break ground, every design detail has been decided and all the materials and parts have been ordered.

During our pre-construction agreement phase, we work together to pick out cabinets, flooring, siding, roofing, windows, doors, plumbing fixtures, and finishes. We make sure everything is figured out before we ever start anything.

The day you sign the contract, we order everything: windows, doors, roofing, siding, framing materials, cabinets, and all fixtures. The only things that we can't order ahead are insulation and plasterboard because they are measured on site. And all of our suppliers know they need to hold materials ready for our schedule.

Doing it this way has a couple benefits. First, we lock in pricing at the moment of order, so you don't end up with materials cost increases. Second, there are never delays waiting for design selections. We will never come to you and ask you what roof color you want when the roof is being installed the next day. We will talk about all of that with you before anything even starts, months prior to when the roof is actually installed.

Traditional construction is always susceptible to these slow downs. The builder reaches a phase, realizes they never finalized the customers choices, and the project stalls while everyone scrambles and materials are ordered. The way we do our pre-construction process eliminates all that.

What Is the Total Project Timeline Including Pre-Construction?

The 100-day guarantee covers construction only, from when we start digging to move-in. But a complete ADU project includes pre-construction work before we start digging.

The usual project takes 45 to 90 days for the pre-construction phase, followed by 100 days of construction. Pre-construction includes surveying, permitting, finalizing design choices, and ordering materials.

There are some things we can't rush though. Things like the surveyor's schedule or the permit review process. But once construction begins, we control the timeline thanks to our streamlined processes.

So if you start your project in March, a typical timeline might look like this: pre-construction through early spring, construction from April to July, and moving in by the end of the summer.

Will I Be Able to Track Progress During the Build?

Yes. Once we are under contract, you get access to our JobTread portal. You get your own login and there's an app as well. The portal shows your real-time construction schedule, so you always know exactly what's happening and what comes next.

During construction, the only time we aren't actively working on your site is when we are waiting for inspections. We don't stop and start construction based on what materials are available because we ordered them day one.

When Is a 100-Day Build Not the Right Fit?

We believe in being very direct about who we are best suited to help. Our 100-day guarantee works because of our specific process and pre-construction decisions. This may not work for every homeowner.

Our methods might not be right for you if you want a lot of highly custom features outside the standard. Or if you need to integrate the systems for the ADU into the already existing house. Or maybe you just prefer to make your materials choices during construction rather than before. Some people like the flexibility to change things mid way through the project, and that's fine. But a different builder may be a better fit for that approach.

For homeowners who want a fast, predictable build with a known move-in date and clear pricing, our methods work best.

Ready to Know Your Move-In Date Before You Start?

A guaranteed build timeline changes the whole experience of adding an ADU to your property. Instead of all this uncertainty, you know exactly when you will be handing keys to a tenant or moving a family member into their new place.

If you want to understand what your specific timeline would look like, including any site factors that might affect your project, we are happy to walk through the details. Learn more about Massachusetts ADU regulations and explore our build process on our website.