Adu cost — Boise City, ID

Last updated: September 24, 2026

What affects the price

Building an ADU involves variables that shift your total investment. The footprint size and complexity of the architectural design are primary factors. Are you planning a detached unit that requires new utility trenching, or is this a garage conversion that uses existing plumbing? Site accessibility, soil conditions, and your choice of finishes—like luxury flooring versus standard options—also play significant roles. Permitting fees vary widely depending on your local municipality and current zoning requirements. Exact pricing confirmed free on the call.

About this service

The cost of your ADU is determined by your choice of foundation, roofing materials, interior finishes, and the current utility connection status of your property. Simple conversions are often more budget-friendly than custom ground-up builds. We provide a breakdown of how different selections impact your bottom line. Exact pricing confirmed free on the call.

Frequently asked in Boise City

Also serving nearby: Meridian · Nampa · Bend · Spokane Valley · Spokane

All cities in Idaho →

More on this: HUD ADU resources — ADU policy and financing research.

Service area details

Serving all of Boise City — population 235,421; about 2,784 residents per square mile across 84.6 sq mi.

Neighborhoods served in Boise City: North End, Bown Crossing, East Boise, West Boise, Downtown Boise — and every surrounding area.