ADUs & Guest Houses
ADUs & guest houses in St. George
A permitted accessory dwelling with its own kitchen, bath, and entrance. Room for aging parents, grown kids, or a long term guest, and rental income when the space is empty.
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- Licensed & insured
- 4.9 on HomeAdvisor
- 20+ years local
Inferno Construction builds ADUs and guest houses across St. George and Washington County: legally permitted accessory dwellings with a full kitchen, bathroom, and separate entrance. We handle the zoning, the utility connections, and the code that comes with a second dwelling, so the space can be lived in full time or rented.
Why Inferno
The permit is the project
An ADU and a guest suite can look identical when they are finished. What separates them is a stack of paperwork, and that paperwork is most of the work. An accessory dwelling unit is a legal second home on your lot, which means it answers to zoning, to setbacks, to parking rules, to utility and metering requirements, and to the building code for a dwelling rather than a room. Get that right and you have an asset you can rent or finance. Get it wrong and you have an unpermitted structure that becomes a problem the day you try to sell.
So we start with what your lot and your city actually allow. Rules for ADUs have shifted in recent years and they differ between St. George, Washington, Hurricane, Ivins, and the unincorporated county. Some allow a detached unit, some only attached, some cap the size or require an extra parking space or owner occupancy. We check your parcel before you spend anything on plans and tell you plainly what is permittable, because there is no point designing a unit your city will not approve.
From there the build is a small, complete home: a full kitchen, a full bath, its own entrance, and often its own utility connections or submeters so you can track what a tenant uses. We coordinate the engineering, pull the permits, and manage the inspections, and we build it to match your house so it reads as part of the property and not as a rental bolted onto the back.
What's included
A complete second home
An ADU is a full dwelling in miniature, held to the same code. The kitchen, the meters, and the permit are what make it legal to live in or rent.
Zoning & permits
We confirm what your lot allows, then handle the zoning, setbacks, engineering, permits, and inspections a second dwelling requires.
Full kitchen
A real kitchen with a range, sink, and appliances, plumbed and wired to code, which is part of what legally makes it a dwelling.
Full bath
A complete bathroom with proper venting and drainage, built to the same standard as the main house, not a half-finished add-on.
Separate entrance
Its own private entrance and, where required, its own address, so a tenant or family member comes and goes independently.
Utilities & metering
Water, sewer, and power run to the unit, with submeters or separate service where the city requires it or you want to bill usage.
Dedicated HVAC
Its own heating and cooling so the unit is comfortable and independent, sized for a Southern Utah summer.
Code-built envelope
Foundation, framing, insulation, and finishes built to dwelling code, so the ADU is financeable and insurable, not just habitable.
Exterior matching
Stucco, roof, windows, and trim matched to your home so the ADU reads as part of the property and protects your resale value.
What goes into it
Every detail, handled in house
One of our additions framed, sheathed, and closed in, windows and slider set, ready for the finishes inside. An ADU is built the same way, as a complete small home. Tap a marker to see what goes into it.
Want this level of detail in your ADU?
Free estimateHow it works
From site visit to final walkthrough
Free site visit
We walk the lot, check what your city allows for an ADU, and talk through whether you want it for family, for rental income, or both.
Plans and permits
Drawings, engineering, and the zoning and permit submittal for a second dwelling, including parking and metering where your city requires it.
Build to dwelling code
Foundation, framing, a full kitchen and bath, utilities and HVAC, and finishes, all built and inspected to the code a dwelling has to meet.
Final walkthrough
We finish inside and out, confirm the unit passes its final inspections, and walk it with you so it is ready to live in or rent.
Real reviews
Homeowners on their projects
Two decades of building across St. George, and a 4.9 rating to show for it. Here is what a few of them had to say.
Questions
ADU & guest house FAQs
What is the difference between an ADU and a casita?
An ADU is a legally permitted accessory dwelling with a full kitchen and its own entrance, which means it can be rented or lived in full time. A casita is usually a detached guest suite with a bath and a kitchenette, meant for family and guests rather than as a separate legal home. The build looks similar. The permitting and the full kitchen are what make it an ADU, and we sort out which one your lot allows before we design anything.
Are ADUs allowed in St. George and Washington County?
Sometimes, and it depends entirely on your city, your zoning, and your lot. The rules have changed in recent years and they differ between St. George, Washington, Hurricane, Ivins, and the unincorporated county. Some allow detached units, some only attached, and some add parking or owner-occupancy requirements. We check your parcel during the free site visit and tell you what is actually permittable before you spend on plans.
Can I rent out an ADU?
That is one of the main reasons people build one, but whether you can rent it, and whether short term rental is allowed, depends on your city's rules and sometimes your HOA. We tell you what your zoning permits up front so you build a unit that can legally do what you want it to do, rather than finding out after it is finished.
Does an ADU need its own utilities?
A full kitchen and bath need water, sewer, and electrical run to the unit, and some cities require separate meters or service for a second dwelling. Even where it is not required, submeters let you track what a tenant uses. We plan the utility connections and metering as part of the design so there are no surprises at inspection.
Will an ADU add value to my property?
A permitted, code-built ADU is an asset. It can generate rental income, house family, and add to what an appraiser and a buyer see, precisely because it is legal and financeable. An unpermitted structure does the opposite, which is why we build to dwelling code and match it to your home rather than cutting corners you would pay for at resale.
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