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

The rules in Goodyear

The unit may not have a separate address from the house. The exterior may differ from the house. A guest house or casita and an ADU may not coexist on the same lot. The unit must be self-contained with a bedroom and bathroom; a kitchen is optional.

Source: City of Goodyear: Zoning Ordinance Article 8-2.C, Accessory Dwelling Unit; goodyear.municipal.codes; goodyearaz.gov; goodyearaz.gov. Read October 7, 2026.

Fees in Goodyear

• Permit and plan review. Valuation-based building safety fees in the Development Services fee schedule; no ADU-specific figure.
• Impact fees. Development impact fees effective April 1, 2024, per single-family home: north zone $4,205 (fire $1,647, parks $1,360, police $1,198, streets $0), south zone $3,573. No ADU line; the 2026 state cap should bring an ADU to a quarter of these.
• Utility connection and capacity. If a new meter is set: north zone 3/4-inch water $8,317 plus wastewater $3,886 plus meter $503, $12,706 together; south zone $15,257. No new meter, no fee.

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 Goodyear 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 Goodyear

Redfin's median sale price in Goodyear is $226 per square foot. A new casita builds for about $265 to $280 per finished foot and a garage conversion for about $120. That puts Goodyear in the "Conversion territory" tier: one square foot of new casita, at the typical $272 build cost, comes out −$102 at a 75% appraiser credit and −$46 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 Goodyear

• 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. Goodyear'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 Goodyear rules for your address.

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