The Casita Bill
Signed in May 2024 and effective January 1, 2025. Every Arizona city over 75,000 residents must allow one attached and one detached ADU on any single-family lot — no special use permit, no variance, no public hearing.
Licensed general contractor · AZ ROC #354956
Add a home to
your backyard.
Rental income, property value, or a place for family to land — built by one licensed team from the first site visit to the final inspection.
2025By-right in AZ cities
1,000 ft²Maximum ADU size
5 ftSetback cap by statute
1Team, start to finish
01 — What changed
Arizona stopped saying no.
Now the answer is by right.
County expansion
Signed May 2025. It carried nearly the same rules out to Arizona's counties, with a compliance deadline of January 1, 2026 — so unincorporated lots are covered too.
What the rules say
Up to 75% of your home's habitable area, capped at 1,000 ft². Setbacks can't be pushed past five feet. Cities can't demand extra parking, can't force your casita to match the house, and can't require you to live on site to rent it long term.
Your HOA still counts
Both bills leave private covenants intact. If your CC&Rs ban accessory dwellings, the association can still say no — whatever the city allows. We check this in the first week, before you spend a dollar on design.
Statute summaries are provided for orientation. Your lot, your city and your CC&Rs decide the real answer — that's the first thing we confirm.
02 — Why homeowners build one
One structure. Four different lives.
Rent it out
A detached casita is a real long-term rental with its own entrance, kitchen and bath. Since 2025 the city can't require you to live on the property to rent it.
Monthly income
Add value to the lot
You're adding permitted, finished, code-compliant square footage with a certificate of occupancy — not a shed.
Property valueWork, guests, pool lounge
An office with a full bath. A guest suite. A shaded room off the pool. The permitted envelope is the same — the layout is yours.
Flexible useOne team, one number to call
We're the general contractor. Design, engineering, permits, trades, inspections and the certificate of occupancy sit with us — you don't chase subs.
Turnkey03 — The same yard
Drag it. That's the whole pitch.
Before
After
Illustration of a typical build, not a photograph of a specific project.
04 — Models
Three footprints. Everything else is yours.
Every unit is site-built with 2×6 exterior framing and a sealed envelope for Arizona summers. Pick the footprint that fits your lot and we adapt the layout, the openings and the finish.
The Studio
One open room, full bath, kitchenette. The pool lounge, the office, the guest suite. Fits the tightest side yards.
- Footprint
- 270 – 400 ft²
- Layout
- Studio · 1 bath
- Ceiling
- 9' flat
- Typical build
- 12 – 16 weeks
The One-Bed
A separate bedroom, a real kitchen and a covered patio. The size most Phoenix homeowners rent out long term.
- Footprint
- 400 – 700 ft²
- Layout
- 1 bed · 1 bath
- Ceiling
- 9' – 10'
- Typical build
- 16 – 22 weeks
The Two-Bed
Full laundry, two bedrooms, a covered patio. Built for family who are staying, not visiting.
- Footprint
- 700 – 1,000 ft²
- Layout
- 2 bed · 1–2 bath
- Ceiling
- 10'
- Typical build
- 20 – 28 weeks
05 — How it's built
Built for 115°, not for the brochure.
Arizona heat finds every gap in a building. The envelope is where a casita either stays cheap to run for thirty years, or doesn't.
- 2×6 exterior framing — deeper cavity, more insulation, a site-built structure rather than a lightweight kit.
- Sealed envelope — spray foam at the roof deck and rim, so the conditioned air stays where you paid to put it.
- Dual-pane low-E glazing — sized and shaded for the west exposure that punishes most yards here.
- Solar-ready roof — conduit and structure staged for panels, whether you add them on day one or year five.
- Desert-rated finishes — stucco and cedar detailing chosen for UV and monsoon, not for a coastal catalogue.
Cedar / stucco rainscreen
Ventilated cavity
Weather barrier
2×6 structural framing
Insulated cavity
Service cavity
Interior finish
Representative assembly. Final specification is set on your engineered plans.
06 — How it works
Five steps. One contractor.
-
01
Feasibility
We pull your parcel, check setbacks, utilities, easements and your CC&Rs, and tell you the largest unit your lot can legally hold. No cost, no obligation.
Week 1 -
02
Design & engineering
Floor plan, elevations and 3D views until it's right, then structural, mechanical, electrical and plumbing drawings stamped for submittal.
Weeks 2 – 6 -
03
Permits
We submit to your city or county, answer plan-review comments and handle the corrections. You get a copy of everything and nothing to chase.
Weeks 4 – 12 -
04
Build
Pad and utilities, framing, envelope, rough-ins, drywall, finishes. One superintendent on site, one weekly update, staged inspections along the way.
12 – 28 weeks -
05
Final inspection & keys
Final city inspection, certificate of occupancy, walkthrough, warranty documents. Then it's a legal dwelling you can move family into or list for rent.
Handover
Timelines are typical ranges for the Phoenix metro. Plan review times vary by municipality and by season.
07 — Casita estimator
Show us the yard. We'll do the math.
Upload a photo or PDF of your space, draw the buildable area on the map, and get an orientation estimate of what a casita there would cost — plus what it could return over ten years.
- 1Your space
- 2Size
- 3Location
- 4Draw it
- 5Estimate
Step 1 · Show us the space
A photo of the backyard, a site plan, a survey PDF — whatever you have. Our assistant reads it and pre-fills what it can. You can also skip this and go straight to the numbers.
- Looks like a yard
- —
- Usable area seen
- —
- Ground surface
- —
- Obstacles
- —
Step 2 · How much casita
Arizona caps an ADU at 75% of your home's habitable area, up to 1,000 ft². Tell us both and we'll flag it if you're over.
Step 3 · Where is it
Your address centers the map on your lot. We only use it to place the drawing and to check we serve your area.
Step 4 · Draw the buildable area
Tap the corners of the part of your yard where the casita could go. Close the shape and we'll measure it.
0 ft² drawn
Last step · Where do we send it
Your estimate appears right here. We'll also keep a copy so a Prime Builders AZ project manager can walk you through it.
Orientation estimate · not a quote
A 500 ft² casita
Estimated build cost
—
— per ft², including a typical site-work allowance
Est. long-term rent—per month, at today's Phoenix rates
10-year net rental income—after a 25% vacancy & upkeep allowance
Added property value in 10 yrs—build cost recaptured, then appreciated
Total 10-year position—in today's dollars, inflation-adjusted
What's behind these numbers
This is an orientation estimate generated from public Phoenix-metro market ranges, not a price from Prime Builders AZ and not a financial projection. Real cost depends on your lot, utilities, grading, finishes and current pricing. A real number comes from a site visit.
Turn this into a real quote08 — Homeowners
Sample content · replace with real reviewsWhat people say after the keys.
The part I didn't expect was the permit stage. They submitted, they answered the city, they told me when something moved. I never opened a portal.
My mother has her own front door and her own kitchen, and she's forty feet away. That was the whole point and it worked exactly like that.
It rented the first month. The summer bills are lower than I budgeted for, which tells me the insulation was not a sales line.
09 — Questions
Before you call us.
Do I need a permit to build a casita in Arizona?
Yes — always. What changed is that in qualifying cities and counties you no longer need a special use permit, a variance or a public hearing. It's an administrative building permit reviewed against the code, and we handle the whole submittal.
How big can my casita legally be?
The cap is 75% of your primary home's habitable area or 1,000 ft², whichever is smaller. Several cities guarantee a minimum around 650 ft² regardless. The estimator on this page checks that for you if you enter your home's size.
Can I rent it out?
For long-term rental, yes, and cities can't require you to live on the property to do it. Short-term rental is a separate question — some municipalities regulate it independently, so we check your specific city before you plan around it.
What if my HOA doesn't allow it?
Then it's a real obstacle. State law expressly preserves private covenants, so CC&Rs that prohibit accessory dwellings still bind you. We read them in week one — before you pay for design — and tell you honestly if this isn't going to work.
How close to my fence can it sit?
Municipalities can't require a setback greater than five feet from the rear or side line for a detached ADU. Easements, utilities and drainage can still constrain placement, which is what the feasibility check is for.
Does it have to match my house?
Not by law — design-matching mandates were removed. Most homeowners still choose finishes that relate to the main house, because it reads better on the lot and at resale. Your call.
How long does the whole thing take?
Plan on roughly six to twelve months door to door: a few weeks of design, plan review that varies by city, and twelve to twenty-eight weeks of construction depending on size. We give you a schedule at contract, and we tell you when it moves.
What does it cost?
There's no honest single answer before someone stands in your yard — utilities, grading, access and finish level move the number more than square footage does. The estimator above gives you an orientation range from public market data; a real figure comes from a site visit and it's free.
10 — Talk to us
Start with the
feasibility check.
It's free and it's the honest first step: what your lot allows, where the unit can sit, and whether this is worth doing at all.
- Call(602) 647-4799
- Emailhello@primebuilderaz.com
- Office3910 W Indian School Rd, Phoenix, AZ
- LicenseAZ ROC #354956