A second home in your backyard.
ADUs & Casitas in Surprise & the Valley
An accessory dwelling unit or casita is one of the smartest additions you can make, a fully finished detached space for aging parents, adult kids, guests or rental income, built to match your home.
Matson Signature Builders builds casitas and ADUs across the Phoenix Valley. Our published 2026 range is $150,000 to $1,000,000+. Cost is driven less by square footage than by type: a garage conversion reuses an existing slab and roof, while a detached casita needs its own foundation, utilities and kitchen. Arizona ROC 336562.
Overview
ADUs & Casitas, Done Right.
Arizona families are embracing ADUs and casitas for good reason: they add flexible living space and real value without the cost of moving. We build detached and attached units complete with kitchenettes or full kitchens, bathrooms, climate control and private entrances, finished to the same standard as the main house.
Whether you want a private suite for visiting family, a quiet home office and studio, or a rentable income unit, we handle design, permitting and construction from start to finish. We'll navigate setbacks, utility connections and county or HOA requirements so your casita is legal, comfortable and built to last.
This is also where our guest house and pool house builds live, detached guest quarters and backyard pool houses are simply casitas designed for a specific use, and we build them all the same way: fully permitted and finished to match your main home.
Good To Know
ADUs & Casitas Questions, Answered
Still have questions? We're happy to talk it through, no obligation.
What's the difference between an ADU, casita and guest house?
They overlap a lot. A casita is typically a smaller detached room or suite; an ADU is a fully independent dwelling with its own kitchen and bath. We build all of them, and help you decide which fits your goals and budget.
Can I rent out my ADU?
In many Valley jurisdictions, yes, rules vary by city and HOA. We build to permit so your unit is legal, and we'll point you to the local requirements that apply to renting.
Will it match my main house?
Yes. We match stucco, roofline, paint and finishes so your ADU or casita looks like a natural part of the property, not an afterthought.
Getting the words right
ADU, casita or guest house?
These get used interchangeably in marketing and precisely at the permit counter, which is where the confusion starts. The kitchen is the hinge: add one and you have created a dwelling unit.
| Term | What it actually means | Has a kitchen? |
|---|---|---|
| Accessory Dwelling Unit (ADU) | The legal term. A self-contained residence on the same lot as a main house, with its own entrance, bathroom, sleeping area and kitchen. | Yes |
| Casita | The Arizona word. Used for a true detached ADU, and loosely for a detached room or suite with no kitchen. | Sometimes |
| Guest house | A marketing term, not a code term. Usually means a casita. | Sometimes |
| Detached bedroom or office | A detached room with no kitchen and often no full bath. Not a dwelling unit. | No |
| Garage conversion | Existing garage space converted to habitable use. Becomes an ADU if a kitchen is added. | If designed as one |
Start Your Project
Let's Talk About Your ADUs & Casitas Project.
Tell us about your project and we'll prepare a detailed, no-pressure estimate, usually within a few business days.
Related reading
Last updated August 2026 · Matson Signature Builders · Licensed Arizona contractor ROC 336562