Building a casita in Chandler: the rules, fees and the math

The rules in Chandler

The unit must use the same water, sewer and electric providers and the same meters as the house. Exterior: stucco or EIFS walls with a concrete tile roof at 4:12, or materials that match the house. A separate independent entrance is required. A lot with an ADU cannot be split unless each piece meets the minimum lot size and has its own utilities.

Source: City of Chandler: Ordinance 5113 (PLH24-0025); chandleraz.gov; chandleraz.gov. Read October 7, 2026.

Fees in Chandler

• Permit and plan review. Standard valuation-based building permit and plan review fees; no ADU-specific figure is published.
• Impact fees. FY 2025–26 system development fees per single-family unit: fire $308, police $74, library $0, arterial streets $3,792, parks by service area ($129 northeast to $5,242 southeast). No ADU line; the 2026 state cap should reduce what an ADU pays.
• Utility connection and capacity. Water $2,460 (3/4-inch meter), wastewater $5,989, reclaimed water $1,094 per single-family unit. Chandler requires the unit to share the house's meters, so whether these are assessed to an ADU at all is something we confirm with the city.

In June 2026 the state capped the development (impact) fees a city may charge an ADU for services other than water and sewer at the lesser of 25% of the single-family fee or the unit's proportionate share, and limited water and sewer fees to the unit's added demand (HB 2946, signed June 5, 2026). Most cities had not yet re-published schedules when we read them; Glendale's 25% ADU line is the first we found. Expect ADU impact fees to fall toward that cap. Governor's announcement.

What the state law guarantees here

Whatever the local code says, in Chandler these points come from A.R.S. § 9-461.18 and the city cannot be stricter:

• At least one attached and one detached ADU on any lot with a single-family home, as a permitted use (no public hearing, no variance)
• A unit up to 75% of the main home's gross floor area or 1,000 sq ft, whichever is smaller (cities may allow larger)
• A third, detached unit on lots of one acre or more if one unit is deed-restricted affordable
• Separate long-term rental of either the house or the ADU (leases of 90 days or more, or month to month)

The math in Chandler

Redfin's median sale price in Chandler is $292 per square foot. A new casita builds for about $265 to $280 per finished foot and a garage conversion for about $120. That puts Chandler in the "Clears at full credit" tier: one square foot of new casita, at the typical $272 build cost, comes out −$53 at a 75% appraiser credit and +$20 at full credit. A conversion clears at either credit.

The target areas page explains the tiers and the math page has the calculator. Rent is the other half: see rental math.

Owners and investors in Chandler

• Homeowners get a by-right unit for family, guests or long-term rent, with the same appraisal and lender rules as anywhere in the Valley.
• Investors can treat the casita as the piece that moves a house out of its neighborhood's price band at resale, as our two Maryvale sales show on the case studies, and as monthly income in the meantime. Chandler's rental rules above say whether both units can be let separately.
• Either way the lot decides: setbacks, utilities, sewer depth and easements. Request a property review and we confirm the current Chandler rules for your address.

Other city pages: Phoenix, Mesa, Gilbert, Scottsdale, Tempe, Glendale, Peoria, Surprise, Goodyear, Buckeye.