Add the Space Your Home Needs
Garages, ADUs, pole barns, and room additions, framed and tied seamlessly into your existing home. As framing contractors, we build additions that look like they were always there.
More Room, Built to Belong
Sometimes the right move isn't a new house; it's more of the one you already love. A garage, an extra bedroom, a bigger kitchen, or a separate living space can transform how your home works without the cost and upheaval of moving.
Advanced Custom Builders builds garages, ADUs, pole barns, room additions, and kitchen or bathroom blowouts across the Missoula area. Because we're framing contractors first, we tie new construction into your existing structure cleanly, matching the framing, the roofline, and the finish so the addition looks original, not bolted on.
Additions That Tie In, Not Stand Out
The hardest part of an addition isn't the new construction; it's joining it to what's already there. Here's how we get it right.
Garages, ADUs, Pole Barns & More
Our additions cover a wide range: attached and detached garages, accessory dwelling units, pole barns, second-story expansions, new room additions, and kitchen or bathroom blowouts that open up the space you already have. Whether you need a workshop, a rental unit, a primary-suite expansion, or simply a bigger kitchen, we've got the framing experience to build it right and the crew to finish it.
Matched to Your Existing Home
Joining new construction to an older home is where additions go wrong: uneven floors, mismatched rooflines, cracks at the seam. We use laser leveling and precise measurements to tie into your existing foundation and roofline, and for older homes we account for settling and use modern engineered lumber to make a flush, structurally sound transition. The goal is simple: an addition that feels like it was part of the original house.
"They did an exceptional job. Tony has an incredible attention to detail, and all my neighbors were super impressed by the speed and quality of their work. His crew were respectful, diligent, hard workers — I would fully trust him on any project."
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Thinking About an ADU?
An ADU (Accessory Dwelling Unit), sometimes called a granny flat or mother-in-law suite, is an independent living space on the same lot as a single-family home with its own kitchen, sleeping area, and bathroom. It can't be sold separately from the primary property, but it can do a lot for you while you own it.
Whether an ADU makes sense depends on your goals, local zoning, and your property layout, but here's why we like them: they can generate steady monthly cash flow or help offset your mortgage; they give aging parents or adult children independent space while keeping family close; and building one on land you already own is often far more affordable than buying a separate investment property. We're happy to walk through whether one fits your lot.
No Job Too Big or Too Small
We take on small projects as readily as large ones, and we find that small projects often build the trust that leads to bigger ones down the road. A quick repair, a single-room addition, or a full-scale build gets the exact same level of detail, communication, and quality from our crew. You won't get brushed off because your project isn't big enough.
"Tony is amazing and fair priced. Quality work each time so far. Had a call back once for a simple fix — his guys had the solution immediately and a quick fix! I always call and always use ACB."
See our profileTony and his team swung trusses the day before hurricane-force winds came through Missoula, and the next morning they were still locked in and solid. I think that is a huge testament to the quality that they put out. I have a large appreciation for the help and consistency to get a project to the finish line in a timely and quality fashion.
Our Additions Process
From the first call to the final walkthrough, here's what working with us looks like:
1. Reach Out
Call or fill out the form with your contact information.
2. On-Site Review
We visit your home, take measurements, and talk through how the addition ties in.
3. Clear, Written Estimate
You get a formal, free estimate with no guesswork and no hidden costs.
4. Permits & Schedule
We handle the permitting and lock in dates that fit your timeline.
5. Build & Tie In
Our crew frames, ties into your existing home, and finishes to match.
6. Walkthrough & Warranty
We finish with a final walkthrough, backed by a one-year workmanship warranty.
The Standards Behind Every Addition
Seamless Tie-In
We use laser leveling and precise measurements to join new construction to your existing home.
Matched to Your Home
We account for settling and match framing, roofline, and finish so the addition looks original.
Permits & Code Handled
We pull the permits and build to the Montana Existing Building Code, so your addition is done by the book.
1-Year Workmanship Warranty
Every addition is backed by a one-year workmanship warranty from the date we finish.
Framing-Crew Built
Additions are framing-heavy work, and framing is our specialty — structure first, always.
Garages, ADUs & More
Garages, ADUs, pole barns, room additions, and kitchen or bathroom blowouts, big or small.
Related Services
Framing
Custom homes, townhomes, apartments, and commercial builds up to six stories, passed the first time.
Learn MoreSiding
Match your addition's exterior to your home: James Hardie, LP SmartSide, Versetta Stone, vinyl, and metal.
Learn MoreDecks
Custom decks in Trex composite and traditional wood framing, built to handle Montana seasons.
Learn MoreAdditions Across Missoula County & Beyond
Additions Questions, Answered
We build attached and detached garages, accessory dwelling units (ADUs), pole barns, second-story expansions, room additions, and kitchen or bathroom blowouts for both small projects and full-scale builds.
We use laser leveling and precise measurements to tie into your existing foundation and roofline. For older homes, we account for settling and use modern engineered lumber to help ensure a flush, structurally sound transition.
An ADU (Accessory Dwelling Unit) is an independent living space on the same lot as a single-family home, sometimes called a granny flat or mother-in-law suite, with a kitchen, sleeping area, and bathroom. It can't be sold separately from the main property. Whether one's worth it depends on your goals, local zoning, and property layout, but ADUs can generate monthly cash flow or offset a mortgage, provide independent space for aging parents or adult children, and are often more affordable than buying a separate investment property.
Yes, most structural additions, second-story expansions, and detached structures require permits to comply with the Montana Existing Building Code. Some smaller accessory structures, such as detached residential sheds under 200 sq. ft., may be exempt, provided they meet local zoning and setback rules. We handle the permitting either way.
Absolutely. We find that small projects often build the trust needed for large projects down the road. Whether it's a quick repair, a full-scale renovation, or a new build, we apply the exact same level of detail, communication, and quality to the job.
Yes. Estimates are free and written in plain terms, every project carries a one-year workmanship warranty, and we're fully licensed and insured. A small travel charge may apply outside a 45-mile radius.
Let's Add Your Space
A garage, an ADU, a bigger kitchen, or a whole new wing, reach out for a free estimate. No job is too big or too small.
Get in Touch
Call or fill out the form with your contact information.
Get Your Estimate
We review the scope and give you a clear, free, written estimate.
We Build It Right
Our crew builds your addition and ties it cleanly into your existing home.