Guest House Builder in Tucson | Pima County Guest Houses

Why "guest house" means something specific here

If your home is in unincorporated Pima County, which takes in the Catalina Foothills, Casas Adobes, Tanque Verde, Green Valley and much of Vail, a detached casita is permitted as a guest house. That is a defined term in the county zoning code with its own rules, and they are not the same as the City of Tucson's ADU rules. Getting the category right at the start saves a redesign later.

Not sure which side of the line you're on? Look up your parcel on the Pima County Assessor site, or ask us on the site walk.

Pima County's guest house rules

Per Pima County's guest house page, a guest house is a detached structure with at least two rooms and a bathroom, and it may have a kitchen. The main rules:

One guest house per lot.
Lot of at least 4,000 sq ft, residential or rural.
Same access as the main home. No new driveway or access point.
No separate utility meters for the guest house.
Setbacks follow the accessory building standards for your zone, and coverage follows the same standards.
Use: primarily by members of the family living in the main home and their non-paying guests.

That last point is the one people miss. A county guest house is built for family and guests, not as a rental unit. If rental income is part of the plan, talk to us early, because the answer depends on where the lot is. Inside the City of Tucson, state law requires that an ADU can be rented long term (see our ADU builder page).

The county's guest house page also says to follow its custom home process for the permit submittal, and setback relief is possible through a modification of setback request or a variance.

Block home with tile roof built by AZ Atlas Builder Group

What shapes a guest house on a county lot

Septic

Many county lots are on septic. A new bathroom and kitchen add flow to that system, so we look at its size and location before design. Septic permits go through Pima County's onsite wastewater process.

Washes and floodplains

Lots near a wash may need a floodplain use permit from the Pima County Flood Control District, which can decide where the guest house sits.

Slope and native plants

Foothills and Tucson Mountains lots are often sloped. The county has hillside development rules and native plant preservation requirements that can apply when grading goes past set limits.

Shared driveway and utilities

Because the guest house shares access and meters with the main home, we plan the path, the trenching for water, sewer or septic, and the electrical load together. An older panel may need an upgrade.

Matching the main house

Block or frame with stucco, tile or flat roof: the guest house should look like it was always there. We do the framing, stucco and roofing with our own crew.

Planning the inside for visitors

A guest house that gets used for weekends and long family visits works best when it's simple to live in and easy to look after:

A real bathroom. A walk-in shower is easier for guests of every age than a tub. Our bathroom team builds them every week.
A kitchenette or full kitchen. The county allows one, and even a small one lets guests keep their own schedule.
Its own cooling. A mini-split means you only cool the guest house when someone is staying.
Shade on the way in. A covered entry or porch makes the walk from the main house comfortable in July.
Storage. A closet with shelving keeps luggage and linens out of the way.

Guest house, ADU or addition?

A guest house gives visiting family real privacy. For a parent moving in full time, an attached suite can be easier day to day (see mother-in-law suites). For your own household, a primary suite addition may be the better spend. Our casita vs home addition guide compares them side by side, and our casita cost guide covers price drivers.

How we build a guest house

Site walk. Jurisdiction, zoning, lot size, access, septic or sewer, slope and washes.
Plans. Floor plan and site plan sized to your zone's accessory building standards.
Permit. Submitted to Pima County Development Services, with septic or floodplain reviews if needed.
Build. Foundation, framing, roof, stucco, utilities and interiors by one licensed contractor (AZ ROC #344537).
Final. Inspections, then a walk-through with you.

Common questions.

Yes. Pima County defines a guest house as a detached structure with at least two rooms and a bathroom, which may have a kitchen.

The county describes a guest house as used primarily by the family in the main home and their non-paying guests, so it is not set up as a rental. If you want rental income, ask us early so we can look at what your lot and jurisdiction allow.

Pima County's guest house page doesn't set one size. Coverage and setbacks follow the accessory building standards for your zone, so the size depends on your lot. We work it out on the site walk.

No. In unincorporated Pima County a guest house must use the same access as the main home and can't have separate utility meters.

A Tucson mailing address can be either. Your parcel record on the Pima County Assessor site shows the jurisdiction, and we confirm it before design.

Yes. A guest house is a new habitable building and needs a building permit from Pima County Development Services, plus septic or floodplain approvals where they apply.

Tell us about your project.

Takes about a minute. Photos help, especially for repairs.