ADU Cost in Wendell, Idaho

What it really costs to build an ADU in Wendell — by type, with Wendell-specific permit fees, rent, and ROI. Straight from local ADU builders.

Quick Answer

An ADU in Wendell, Idaho typically costs $80,000 – $150,000 for a garage conversion, $150,000 – $350,000 for a detached new build, and $150,000 – $280,000 all-in for a pre-fab/modular unit (roughly $150 – $300 per square foot finished). Add permits and impact fees on top.

ADU Cost by Type in Wendell

ADU TypeTypical Wendell CostTimelineBest For
Garage Conversion$80,000 – $150,0002–4 monthsLowest cost; existing garage in good shape
Detached New Build$150,000 – $350,0004–8 monthsMaximum size + design flexibility
Pre-Fab / Modular$150,000 – $280,0008–14 weeks on-siteFaster on-site; straightforward lots
Per square foot (finished)$150 – $300 / sq ft

Permits & Fees in Wendell

Confirm permit fees with Wendell City Hall (208-536-5161). County impact-area parcels follow Gooding County.

These are in addition to the construction cost above. We get exact fee quotes from the local office for your specific project during the Feasibility Check — see our full line-item cost breakdown + ROI calculator for how the numbers add up.

Rental Income & ROI in Wendell

A 1-bedroom ADU in Wendell typically rents for $750–$1,100/month long-term (estimate). At this rate, an ADU often offsets much or all of its financing payment within a few years, on top of the 20–30% property value increase ADUs typically deliver (per FHFA research).

Want the exact numbers for your property and goals? Our free eligibility check tells you your maximum ADU size, and the Feasibility Check gives you a good/better/best budget for Wendell.

Cost ranges reflect 2026 Magic Valley pricing and vary with lot conditions, finish level, and whether your existing home needs electrical or sewer upgrades. The high end applies when the lot has access constraints, the home needs system upgrades, or you choose premium finishes. We confirm a real budget range for your specific Wendell property during the Feasibility Check.

Get Your Real ADU Budget for Wendell

Start with a free 10-15 minute Readiness Call, then book a Feasibility Check for a detailed good/better/best budget tailored to your property.