ADU Cost in Rupert, Idaho
What it really costs to build an ADU in Rupert — by type, with Rupert-specific permit fees, rent, and ROI. Straight from local ADU builders.
Quick Answer
An ADU in Rupert, 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 Rupert
| ADU Type | Typical Rupert Cost | Timeline | Best For |
|---|---|---|---|
| Garage Conversion | $80,000 – $150,000 | 2–4 months | Lowest cost; existing garage in good shape |
| Detached New Build | $150,000 – $350,000 | 4–8 months | Maximum size + design flexibility |
| Pre-Fab / Modular | $150,000 – $280,000 | 8–14 weeks on-site | Faster on-site; straightforward lots |
| Per square foot (finished) | $150 – $300 / sq ft | ||
Permits & Fees in Rupert
Valuation-based building permits through Minidoka County (208-436-7183). No flat ADU fee published.
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 Rupert
A 1-bedroom ADU in Rupert typically rents for $700–$1,300/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 Rupert.
More for Rupert Homeowners
ADU Rules in Rupert
Zoning authority, size limits, setbacks, and SB 1354 status for Minidoka County.
Full Cost Breakdown
13-category line-item breakdown + interactive ROI calculator.
Am I Eligible?
Instant check: your max ADU size + which floor plans fit your lot.
Financing
HELOC, construction loan, cash-out refi — and Idaho lender options.
Get Your Real ADU Budget for Rupert
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.