Can I add a loft to my detached ADU?  Yes—Scottsdale allows a maximum height of 26 ft for detached ADUs. We can design a vaulted roofline with a sleeping loft as long as the total habitable square footage (including the loft) stays within the 1,000 sq ft cap and you maintain the 10 ft separation from the primary home.

Are there impact fees for a backyard ADU? Scottsdale does not levy separate development impact fees on ADUs under 1,000 sq ft, but you will pay standard building-permit fees and utility hookup charges (typically $2,500–$3,500 combined). On lots larger than one acre adding a second “restricted-affordable” unit, the city may waive a portion of fees to encourage affordable housing.

What roofing materials are permitted? Any Class A fire-rated roof approved in the International Residential Code is acceptable—-the most common are architectural shingles, standing-seam metal, and concrete tile. HOA design guidelines (if applicable) may further restrict color or material, and we’ll match or complement the primary dwelling to speed approvals.

Can I tie the ADU into my existing septic system? If your property uses septic, Maricopa County Environmental Services must verify the tank capacity and leach-field size. For units ≤ 1,000 sq ft, a tank upgrade is seldom required; we submit the septic alteration permit concurrently with the city building permit so the timeline isn’t delayed.