ADU Construction in New Plymouth, Idaho
Iron Crest Remodel provides expert adu construction services to homeowners in New Plymouth and surrounding Payette County communities. Accessory dwelling units and backyard cottages in Boise.
Looking for professional adu construction in New Plymouth, Idaho? Iron Crest Remodel serves New Plymouth homeowners with the same quality, warranties, and professionalism we bring to every Treasure Valley project. Located ~50 miles from HQ, New Plymouth is within our core service area with quick response times.
- Custom ADU design (studio to 2-bedroom)
- Full kitchen and bathroom builds
- Independent utility connections
- Zoning and permit management
- Foundation and framing
- Insulation and HVAC systems
- Interior and exterior finishes
- Landscaping and site restoration
- ADA-accessible ADU options
- Garage conversion to ADU
Timeline
4 – 8 months
Feasibility Assessment
We evaluate your property for ADU eligibility — lot size, setbacks, zoning, utility access, and site conditions. You receive a feasibility report with size and placement options.
Design & Permitting
Architectural plans are developed, engineered, and submitted for building permits. We coordinate with the City of Boise and Ada County for all required approvals.
Site Work & Construction
Foundation, framing, roofing, siding, windows, and doors are completed. Plumbing, electrical, and HVAC are installed. Interior finishes follow.
Final Inspections & Occupancy
All required inspections are completed, certificate of occupancy is obtained, and the ADU is ready for use — whether for family, guests, or rental income.
Can I build an ADU on my property in Boise?
Boise adopted updated ADU regulations that allow accessory dwelling units on most residential lots. Requirements include minimum lot size, setback distances, and maximum ADU size limits. Iron Crest Remodel evaluates your property eligibility during the initial consultation.
How much does an ADU cost to build in Boise?
ADU construction in Boise typically costs $150,000-$300,000 depending on size, finishes, and site conditions. A basic 400 sq ft studio ADU starts around $120,000. A full 800 sq ft one-bedroom unit with premium finishes can reach $250,000+.
How long does it take to build an ADU?
From permit approval to completion, ADU construction takes 4-8 months. The permitting process itself can take 4-12 weeks depending on the jurisdiction and complexity.
Not every adu construction project is the same. Cosmetic updates are minor refreshes — not full remodels. Full remodels start at the Standard tier and above. Here are the most common scope levels we handle in the Boise area, with typical investment ranges.
Garage Conversion
$80,000 – $150,000
Convert an existing attached or detached garage into a living unit. Lower cost because the shell exists. Plumbing, electrical, insulation, and finishes required.
Studio ADU (400–500 sq ft)
$120,000 – $200,000
Compact open-plan unit with kitchenette, bathroom, and combined living/sleeping area. Most affordable new-build option.
One-Bedroom ADU (500–800 sq ft)
$180,000 – $280,000
Separate bedroom, full kitchen, bathroom, and living area. Most popular size for Boise rental ADUs.
Two-Bedroom ADU (800–1,000 sq ft)
$250,000 – $350,000+
Full-size dwelling with two bedrooms, full kitchen and bath, and dedicated living space. Maximum rental income potential.
Remodeling in the Treasure Valley comes with local factors that affect scope, cost, and timeline. Here is what Boise-area homeowners should know.
Boise ADU Zoning
Boise allows ADUs on most R-1 residential lots. Maximum size is typically 10% of lot area or 900 sq ft, whichever is less. ADUs must maintain primary dwelling setbacks and can be detached or attached.
Utility Connections
New ADUs require separate water, sewer, and electrical connections. Boise City water/sewer connection fees run $8,000–$15,000. Electrical service panel and meter add $3,000–$6,000.
Rental Market
Boise ADU rental rates average $1,200–$1,800/month for studios and $1,500–$2,200/month for one-bedrooms (2024 market data). Strong rental demand from Boise State students, young professionals, and remote workers.
Fire Separation
Detached ADUs within 5 feet of the primary dwelling or property line require one-hour fire-rated construction. This affects wall assembly, sheathing, and siding choices.
Choosing between detached adu (new build) and garage conversion? Here is a side-by-side comparison to help you decide.
| Factor | Detached ADU (New Build) | Garage Conversion |
|---|---|---|
| Cost | $180,000–$350,000 | $80,000–$150,000 |
| Timeline | 5–8 months | 3–5 months |
| Privacy | Fully separate structure | Adjacent to main home |
| Parking Impact | No garage lost | Lose garage parking |
| Design Freedom | Unlimited layout options | Constrained by existing shell |
Plan your adu construction project with our in-depth guides.
Explore our in-depth guides to understand adu construction costs, timelines, and planning details for cities across the Treasure Valley.
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Iron Crest Remodel brings adu construction expertise directly to New Plymouth, ID. Located ~50 miles from HQ, New Plymouth is within our core service area — close enough for quick site visits, material deliveries, and responsive project management.
ADU Construction costs in New Plymouth depend on project scope, materials selected, and site conditions. The ranges below reflect our experience across Payette County and the broader Treasure Valley market. Every Iron Crest proposal includes a detailed, line-item breakdown — no vague allowances or hidden fees.
| Detail | Estimate |
|---|---|
| Typical Cost Range | $120,000 – $300,000+ |
| Typical Timeline | 4 – 8 months |
| Free Estimate | Yes — in-home consultation, no obligation |
| Pricing Model | Fixed-price proposal with line-item detail |
Contact us for a free, project-specific estimate for your New Plymouth home.Request your free estimate →
Research your adu construction project with our in-depth Boise-area guides covering costs, timelines, materials, design ideas, and permit requirements.
We provide adu construction services throughout New Plymouth, including these neighborhoods and surrounding areas.
New Plymouth's housing stock is a mix of original farmhouses from the early-to-mid 1900s, single-story ranch homes built in the 1960s–1980s, and newer construction from the 2000s onward. Farmhouses often feature solid wood framing and plaster walls but outdated plumbing and electrical. Ranch homes typically have galley kitchens with limited counter space. Newer builds offer open floor plans but may use builder-grade finishes that homeowners want to upgrade within 10–15 years.
“We had an old farmhouse kitchen with barely any counter space and outdated wiring. Iron Crest completely transformed it — new cabinets, quartz counters, proper electrical, and an island we use every single day. They handled the Payette County permits and every inspection without us lifting a finger.”
— Mike & Teresa R., Rural New Plymouth | Kitchen Remodeling
“Our 1970s ranch home had the classic closed-off galley kitchen. Iron Crest opened it up to the living room, added a breakfast bar, and installed beautiful LVP flooring throughout. The crew drove out from Boise every day and always showed up on time. Couldn't be happier with the result.”
— Jennifer L., North New Plymouth | Kitchen Remodeling
“Iron Crest replaced our bathroom tile and vanity while also updating the kitchen countertops and backsplash. They coordinated both projects to minimize disruption and finished ahead of schedule. Professional, clean, and the quality is outstanding for the price.”
— David & Susan K., Downtown New Plymouth | Kitchen & Bathroom Remodeling
- Kitchen remodels involving plumbing, electrical, or structural changes require a Payette County building permit
- Permit fees are typically $75–$250 depending on project scope — lower than Ada County rates
- Plan review turnaround is usually 1–2 weeks, significantly faster than Boise metro jurisdictions
- Inspections are scheduled through the Payette County Building Department and typically occur within 2–3 business days of request
- Iron Crest Remodel handles all permit applications, plan submissions, and inspection scheduling as part of our fixed-price contracts
Iron Crest Remodel handles all permit applications, plan submissions, and inspection scheduling for your adu construction project in New Plymouth. Permit requirements and fees are included in our fixed-price proposals.
Ready to start your adu construction project in New Plymouth? Here are the next steps to get your project moving.
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