Accessory Dwelling Units

Custom ADUs for Treasure Valley Homeowners

Rental Income, Family Space, or Both
25+ years building custom homes and additions in the Treasure Valley. Licensed, insured, and local — from your free consultation to your final walkthrough.

25+ Years of Experience

Custom Design & Build Approach

Licensed, Bonded & Insured

Local & Trusted in the Treasure Valley

WHY HOMEOWNERS ARE BUILDING ADUS RIGHT NOW

On July 1, 2026, Idaho’s new ADU law (SB 1354) took effect, guaranteeing homeowners in Boise, Meridian, Nampa, and other Treasure Valley cities the right to add an accessory dwelling unit to their property — with fewer of the old roadblocks around parking, HOA restrictions, and owner-occupancy rules. If you’ve been putting off an ADU because you weren’t sure it was allowed on your lot, now’s the time to find out.

We’ll walk you through what’s actually possible on your specific property — for free.

ADUs are one of several things we build as a Treasure Valley construction company, alongside custom homes, additions, shops and garages.

Rental Income

Long-term rentals are permitted throughout the Boise area; a well-built ADU can meaningfully offset your mortgage.

Multigenerational Living

Keep aging parents or adult kids close, with their own private space.

Home Office or Studio

A dedicated space away from the main house, without a commute.

Increase Property Value

A permitted ADU is a real asset appraisers and buyers recognize.

WHAT WE BUILD

Detached, Attached, or Above the Garage — We Build ADUs That Fit Your Property

Not every lot works the same way, and not every ADU should look the same. We design and build:

Detached ADUs

Standalone backyard cottages, fully independent from the main house

Attached ADUs

Additions that share a wall with your home, often the more cost-effective option

Garage Conversions

Turn existing square footage into a livable unit

Every ADU we build looks like it belongs — matched to your home’s style, not a bolt-on structure.

working steps

Our Working Process

01

Schedule your free consultation

Tell us a little more about your project and our team will reach out to schedule your free in home consultation. We’ll use this opportunity to see the space, learn more about your ideas, and come up with a custom plan for how we can create your dream space together.

02

Finalize the Plan

Our team of experts will take very detailed notes to make sure all of your wishes are taken into account when we build your tailored plan for bringing your project to life. Once we have the plan ready for review, we’ll schedule a follow-up meeting to present this finalized plan to you for approval, ensuring you’re completely satisfied with every detail before any construction begins.

03

Watch Your Dream Come to Life

This is where the magic happens! Our experienced team of craftsmen will begin the construction process, carefully executing each step of the plan we’ve created together. You’ll be kept in the loop every step of the way as your dream begins to take shape.

04

Adding the Finishing Touches

As the project is nearing completion, we will walk through the space together to make sure no details have been missed and that you are absolutely in love with the finished product.

05

Enjoy Your New Space

Once the project is complete, it’s time to relax and enjoy the beautiful, functional space we’ve created together. From start to finish, we’re committed to making your home feel exactly the way you’ve always envisioned.

WHY CHOOSE US

Comfort Expert Builders

With decades of hands-on experience, personalized design solutions, and clear communication, Comfort Expert Builders makes every project feel straightforward and dependable. Our licensed and insured team delivers quality craftsmanship while treating every home and property with care.

Custom Design & Build Approach

Every project is thoughtfully designed and built around your vision, needs, property, and long-term goals.

Transparent Communication

We keep you informed at every stage with clear updates, honest guidance, and responsive communication from start to finish.

Licensed, Bonded & Insured

Work with confidence knowing your project is handled by a fully licensed, bonded, and insured construction team.

Local & Trusted

As a trusted local builder, we understand the community and take pride in delivering dependable service and lasting craftsmanship.

Reviews

Built on Trust. Proven by Our Clients.

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Arturo Davila profile picture
Arturo Davila
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Alex came in and did exactly what he said in a timely manner, his employee was excellent and very professional, I would highly recommend them and will definitely use them in the future.
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Cora Wayenberg profile picture
Cora Wayenberg
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First time doing any kind of construction and an ADU above our garage was quite the experience! Alex was good at letting us know each step of the way. We had a hiccup with cabinets....but even with that delay, project was done within a week of when he said it would b done! I've been told, in the construction world, that's miracle! He worked with us to keep us within our budget....even assisting on some areas so it would b amazing! I loved that he didn't "nickle & dime" us to death!! Anything extra needed was carefully shared & explained. The finished product is so much more than we could have hoped for & admired by all who view it! Thank you Alex & CEB!!
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Evy Lobkov profile picture
Evy Lobkov
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did a great job with our house remodel!! very professional and made sure we got what we wanted. would recommend
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Reagan Olson profile picture
Reagan Olson
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We recently had the pleasure of working with Alex from Comfort Expert Builders, who completed a ~1400SQ FT addition above our garage. From start to finish, Alex was great to work with. He was professional, approachable, and always ready to address any questions or concerns. His team moved quickly and completed our project in an impressive 3-months! Throughout the project, Alex maintained excellent communication, keeping us informed of progress and any potential issues. The construction estimate was accurate, and there were no unexpected costs or surprises. His level of honesty and reliability is rare and highly appreciated. Overall, I would highly recommend Comfort Expert Builders for any home construction projects.
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Zach Redd profile picture
Zach Redd
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Comfort Expert Builders, is a great business partner of ours in the treasure valley. As a Business owner myself, I appreciate good communication, reliability, and expertise is ones field. That’s exactly what you get with Alex and his team. I highly recommend them to anyone building in the area.
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olga derbis profile picture
olga derbis
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Alex and his team have been a pleasure to work with! First of all, always easy to communicate with, and responding in a timely fashion. We always felt comfortable asking questions, and if a change in the plan was needed, they were accommodating and patient. And secondly, very professional and work quality speaks for itself. Would definitely recommend to friends and family!

ADU Questions? Here's What Treasure Valley Homeowners Ask Us Most

What does an ADU cost in the Boise area?

Costs vary widely based on size, whether it’s attached or detached, site conditions, and finish level — a garage conversion runs very differently than a ground-up detached unit. We’ll give you a real, project-specific estimate after seeing your property, not a generic number that doesn’t apply to your lot.

As of July 2026, Idaho’s new state law guarantees most homeowners in cities over 10,000 people — including Boise, Meridian, and Nampa — the right to build at least one ADU, up to their city’s maximum allowed size. But your specific zoning, lot size, city, and (if applicable) HOA rules still matter. We build across the whole Treasure Valley, so we’ll check the exact rules for your address as part of your free consultation, before you spend a dollar on design.

Every ADU in Boise requires city approval through Planning & Development Services. Permit costs and timelines depend on your project scope. Because we build ADUs regularly in the Treasure Valley, we know what the planning department expects and can help you avoid the common delays — like footprint or setback issues — before they cost you time.

Timelines depend on design complexity, permitting, and whether you’re doing a conversion or new construction. We’ll give you a realistic timeline specific to your project during your consultation, and keep you updated at every stage — no disappearing for months at a time.

Sometimes, yes. City approval and HOA approval are separate — even where the city allows an ADU, older HOA covenants may still restrict it. We recommend checking your CC&Rs early, and we’re happy to help you understand what you’re looking at.

Long-term rentals are generally allowed in the Treasure Valley. Short-term/Airbnb-style rentals are more restricted. We can talk through what’s realistic for your goals.

Get a Free ADU Estimate for Your Treasure Valley Property

Tell us a little about your property and what you’re hoping to build. We’ll research any zoning or permitting details for your specific address ahead of time, so your free consultation actually gets you answers — not just a sales pitch.

We’ll respond within one business day. No obligation.

We’ll research any local zoning or permitting restrictions ahead of time.