Casita cost per square foot by size and finish
Pick your size row, then your finish column. We split each sourced range into three equal bands: Basic, Standard and High-end. The calculator uses these exact numbers.
| Casita living space | Basic | Standard | High-end |
|---|---|---|---|
| Casita, under 500 sq ft | $270 to $312 | $312 to $354 | $354 to $396 |
| Casita, 500 sq ft and up | $195 to $218 | $218 to $242 | $242 to $265 |
Bath and kitchen level moves you up: a full kitchen moves you up one band, two baths plus a full kitchen move you up two. High-end is the top. A long utility run or a new 200A subpanel adds $4,500 to $8,000.
Watch the 500 sq ft line. A 490 sq ft casita can price higher than a 520 sq ft one, because it uses the small-unit rate. That is how published prices behave too: the smallest models carry the highest cost per foot.
Worked examples
Each row uses the same math as the calculator.
| Example (same math as the calculator) | Planning range |
|---|---|
| 400 sq ft casita, Standard finish, 1 bath + kitchenette, short utility run | $124,800 to $141,600 |
| 800 sq ft casita, Basic finish, 1 bath + full kitchen (moves to Standard band), long utility run | $178,900 to $201,600 |
| 1,000 sq ft casita, High-end finish, 2 baths + full kitchen | $242,000 to $265,000 |
| 600 sq ft casita plus 24x45 (1,080 sq ft) stucco RV bay, Standard finish | $233,400 to $291,000 |
| 20x40 (800 sq ft) stucco garage or shop | $76,000 to $108,000 |
| 24x50 (1,200 sq ft) insulated AC shop, 14 ft door | $156,000 to $198,000 |
Across all finish levels, a 600 sq ft casita runs $117,000 to $159,000. A 600 sq ft casita plus a 24x45 stucco RV bay runs $219,600 to $304,800.
Where the money goes
Below is a 600 sq ft Standard casita split into line items. The last row is the balance (plumbing, electrical, interior finishes, bath, kitchen, builder overhead and contingency), so the rows add up to the total. Permits and plan review fees have their own row.
| Line item | Low | High |
|---|---|---|
| Site prep, grading and engineering | $5,600 | $7,400 |
| Concrete slab (600 sq ft) | $9,100 | $10,100 |
| Framing (600 sq ft) | $14,500 | $16,700 |
| Exterior walls and roof (600 sq ft) | $12,000 | $13,800 |
| Mini-split AC for the casita | $4,500 | $5,800 |
| Permits and plan review fees | $1,100 | $1,700 |
| Plumbing, electrical, interior finishes, bath, kitchen, builder overhead and contingency (balance) | $84,000 | $89,700 |
| Total | $130,800 | $145,200 |
Our line-item planning rates: slab $14 to $18, framing $22 to $30, and exterior walls and roof $18 to $25 per sq ft. Grading and engineering run $4,500 to $8,500, and a mini-split $3,800 to $6,500.
When your total range is narrow, we narrow each line item toward its middle. That keeps every row in order, and the rows still add up to the total.
Permit fees in the area have run about $800 to $2,000. For example, Mesa permits for detached RV garages showed fees of about $830 to $920 on city open data.
Already have a bid? Free fair price check
Enter your builder's bid total, the project, the size and your city. You see right away where it falls in our 2026 planning ranges. We compare numbers only. We do not rate builders.
How we set these numbers
We compared published casita prices from builders who serve the East Valley, permit valuations from city open data, and guide sites. Mid-size published prices ran about $212 to $293 per sq ft. Units under 500 sq ft ran about $270 to $396.
Some builders advertise lower starter prices on small models, so always ask what is included: plans, permits, utility runs, site work and AC.
Permit valuations are not contract prices. Cities often use a fixed table, so use them as a floor.
Paying for it: HELOC example
Many owners use a home equity line of credit (HELOC). At an example rate of 7.2% APR paid off over 20 years, each $100,000 borrowed costs about $787 a month. That rate is only an example, not an offer. Many HELOCs start interest-only, so real payments vary. Ask a lender for your real rate.
Next steps
- Run your numbers in the casita cost calculator.
- Check your city or county rules and your HOA.
- Adding a shop? See shops and RV garages.
- When ready, get a free quote from a licensed builder.
Frequently asked questions
Why do small casitas cost more per square foot?
A kitchen, a bathroom, AC and utility hookups cost about the same in a 350 sq ft casita as in a 700 sq ft one. Spread over fewer square feet, the cost per foot goes up. That is why our table uses $270 to $396 under 500 sq ft.
Do these prices include permits?
Yes. Our line items include a permits and plan review fees row of about $800 to $2,000. Impact or utility fees, if your city charges them, can add more. Ask your city.
Is a HELOC the only way to pay?
No. Owners also use cash, a cash-out refinance, a construction loan or a renovation loan. The HELOC payment we show is an example at 7.2% APR to help you plan, not an offer.
Why is there no steel building price?
We have not confirmed a local turnkey price for a red-iron steel building with slab, doors and electric. Kits alone are a small part of the total.
Sources
- Space Break (Gilbert casitas): 250 sq ft $99K, 500 sq ft $135K, 800 sq ft $175K, 1,000 sq ft $220K
- Casita Kings (Mesa area): 576 sq ft $165K, 768 sq ft $225K, 990 sq ft $245K
- Prime Builders (Queen Creek casitas): 325 sq ft $69,900, 400 sq ft $84,900
- Jematell Homes: 400 to 800 sq ft casitas $100,000 to $280,000
- Jematell Homes: Arizona RV garage tiers, 2026
- HomeAdvisor: RV garage cost, updated Jun 19, 2026
- City of Mesa building permits open data (valuations)
- Town of Gilbert permit data (EnergovPermitData layer)
All sources checked Oct 29, 2026.