ADU Contractor in Twin Falls, Idaho
Twin Falls ADU Guys is your local ADU expert — based in Twin Falls, fully versed in the City Uniform Development Code, and ready to guide you from idea to move-in.
ADU Services in Twin Falls
If you own a home in Twin Falls and want to build an ADU, you're in the right place. We are based here, we know the Twin Falls Building Department and Planning and Zoning office, and we've built the relationships that make projects move faster. We know Title 10 of the Twin Falls Uniform Development Code inside and out — the 45% size rule, setback requirements by district (R-2, TN-1, TN-2, TN-3, RR), the utility sharing requirement, and the Zoning Use Permit application process.
Permitting in Twin Falls
Twin Falls follows Title 10, Section 10-6-10-B of the Uniform Development Code. ADUs are permitted on any legal lot with a single household dwelling. The 45% rule limits ADU size to 45% of the principal residence's living space. Zoning Use Permit required ($250 fee).
ADU Rules in Twin Falls
SB 1354 appliesTwin Falls (population ~54,900) is over 10,000, so Idaho SB 1354 (effective July 1, 2026) requires the city to allow at least one ADU per single-family lot by-right — and the city already permits ADUs under its own Title 10-6-10-B. The city must align its code with SB 1354 by February 1, 2027.
- Zoning authority
- City of Twin Falls Planning & Zoning, 203 Main Ave E (208-735-7267, tfplanning@tfid.org)
- ADU size limit
- Up to 45% of the principal residence living space (Title 10-6-10-B). SB 1354 also sets a statewide floor — bound cities may not cap ADUs below 1,000 sq ft or 75% of the primary dwelling, so the city's rule may be revised upward by Feb 2027.
- Setbacks
- By zoning district (R-2, TN-1, TN-2, TN-3, RR). Detached ADUs under 15 ft: 20' front, 3' side, 3' rear. See our Idaho ADU Laws page for the full table.
- Permits & fees
- $250 Zoning Use Permit + building/trade permits + Idaho impact fees (~$6k-$10k). Under SB 1354, ADU fees may not exceed those for a single-family home.
- Owner-occupancy
- No owner-occupancy mandate; ADU may not be sold separately. SB 1354 prohibits bound cities from requiring owner-occupancy.
- Typical 1BR ADU rent
- $900-$1,400/month
What an ADU Can Do for Twin Falls Homeowners
ADU Types We Build
- ✓Detached new build ADU
- ✓Garage conversion ADU
- ✓Attached ADU addition
- ✓Pre-fabricated ADU installation
- ✓Basement conversion (where applicable)
Full-Service Includes
- ✓Feasibility assessment + site visit
- ✓Custom ADU design
- ✓All permit applications and coordination
- ✓General contracting + all trades
- ✓Final inspection + Certificate of Occupancy
Idaho SB 1354 Protects Your Right to Build in Twin Falls
Because Twin Falls has a population over 10,000, Idaho Senate Bill 1354 (effective July 1, 2026) requires it to allow at least one ADU per single-family lot as a by-right use, and the city must align its code by February 1, 2027. Separately, Idaho HB 166 protects an internal ADU on an owner-occupied homestead from HOA bans. Learn more about Idaho ADU law →
How We Build Your ADU in Twin Falls
The same proven 4-step process we use across the Magic Valley
Free Readiness Call
10-15 minutes. We learn about your property and goals, and confirm whether a Feasibility Check makes sense.
Feasibility Check ($250-$750)
On-site visit, measurements, zoning verification with your local planning department, utility assessment, and a complete report with budget range.
Design + Permits
We design your ADU to code and handle every permit application with your city and county building department.
Construction
Our licensed team handles all trades — framing, plumbing, electrical, HVAC, and finishes. One team, start to finish.
Plan Your ADU in Twin Falls
Whether you are just researching or ready to start, here is everything you need to know about building an ADU in Twin Falls County.
Cost in Twin Falls
ADU pricing for Twin Falls County — garage conversion vs detached vs prefab, with hidden costs explained.
Permits in Twin Falls
How we handle the full permit process — Zoning Use Permit, building permits, trade permits, inspections.
Financing Options
HELOC, construction loans, cash-out refinance, FHA — how Twin Falls homeowners pay for their ADU.
Idaho ADU Law
HB 166, HOA rules, the 45% size rule — what state and local law actually requires.
Ready to Build an ADU in Twin Falls?
Start with a free 10-15 minute Readiness Call. We'll assess your property, walk through the local permit process, and tell you exactly what's possible.