Irontown Modular · Authorized Dealer

Modular ADU homes in Idaho

Make room for family or guests with Irontown’s ADU plans, backed by more than 40 years of building experience. My Cozy Outdoors is your authorized Irontown Modular dealer and direct point of contact. Irontown is the seller of record.

Designed to the International Residential Code Idaho adopts statewide; set on a permanent foundation.
Delivery and crane set included for the first 250 miles; additional mileage charged per truckload.
Free zoning guidance with your quote.
10 year limited structural warranty.

Get a Quote and Zoning Guidance See the City and County Rules

Irontown Modular Morada 1000 modular ADU

What counts as an ADU in Idaho?

Idaho defines an accessory dwelling unit as a self-contained living unit with cooking, sleeping and sanitation facilities on the same lot as a single-family primary dwelling: internal, attached or detached. Mother-in-law suite, guest house, backyard cottage, casita, granny flat, tiny home and prefab ADU are everyday names.

A modular ADU is factory-built to the International Residential Code Idaho adopts for site-built houses, with engineered stamped plans, then crane-set on a permanent foundation as real property. A wheeled park model, what Idaho law calls a park model recreational vehicle, and any tiny home on wheels are outside the state ADU law and this page.

Where can you put a modular ADU?

Start with the city limits: county land follows different rules. Before ordering, confirm requirements with city or county planning and building offices, and septic and well capacity with the health district.

Start With Local Guidance
This guide is a starting point. MCO helps and advises but takes no responsibility for zoning, permits, impact fees, septic approval or code compliance. Before ordering, you must confirm your parcel, model and use with city or county planning and building offices, and septic approval with the health department. We strongly recommend contacting those offices. MCO can share the code sections it found and suggest questions.

Idaho’s statewide ADU law

Idaho Code 67-6541 took effect July 1, 2026, binding cities over 10,000 people. Counties and smaller towns follow their own codes. Cities have until February 1, 2027 to rewrite their rules; most had not when read in September 2026.

Bound cities cannot ban ADUs in residential zones. Projects meeting city requirements receive administrative approval as a matter of right, without a hearing.
By February 1, 2027, allow one internal or detached ADU per lot; no cap below 1,000 sq ft or 75 percent of the house.
No owner-occupancy requirement; ADU parking only in three exceptions; height cannot be below your house; setbacks, lot size, coverage and frontage cannot be stricter than house rules.
ADU impact fees and utility connection fees cannot exceed those imposed on another single-family home.
Building codes, fire safety, floodplain, water, sewer, storm drainage, road access, environmental and easement rules remain. Historic districts retain protections.
Counties and towns of 10,000 or fewer follow local codes. Middleton, Hailey, Rathdrum and Sandpoint depend on which population figure applies.

Rules inside Idaho city limits

Listed Treasure Valley, eastern Idaho, Magic Valley and Panhandle cities over 10,000 are bound, with updates due February 1, 2027. Rows show published codes; ask cities with conflicting rules how they apply state law now. Smaller resort towns follow local codes.

City	Detached ADU	What the local rule says
Boise	Allowed with conditions	BCC 11-03-03.2.B caps units at 900 sq ft or 70 percent of your house, whichever is less; ask how state law applies now. Phone 208-608-7100.
Meridian	Allowed with conditions	UDC 11-4-3-12 caps units at 900 sq ft or half your house, whichever is less; you must connect to city water and sewer. Phone 208-884-5533.
Nampa	Allowed with conditions	NCC 10-1-2, 10-3-2 caps units at 500 sq ft; ask about ZTA-00049-2026 after its September 8 hearing. Phone 208-468-4430.
Caldwell	Allowed with conditions	CCC 10-05-03, 10-12-03-1 caps units at 900 sq ft or 75 percent of your house, whichever is less; you cannot sell the unit separately. Phone 208-455-3000.
Eagle	Allowed with conditions	ECC 8-3-5.U caps units at 500, 640, 800 or 1,200 sq ft by lot size; lots generally need 17,000 sq ft, and separate sales are barred. Phone 208-939-0227.
Kuna	Allowed with conditions	KCC 5-8-503, note 7 has no size cap but requires a special-use hearing; ask how the city applies state law now. Phone 208-629-8853.
Star	Allowed with conditions	Under 8-5-30, detached units are capped at half your house’s footprint; the owner must live on the property; lots must be at least 10,000 sq ft; ask what applies now. Phone 208-286-7247.
Garden City	Ask first	Section 8-2C-14 could not be read, so the size cap is unknown; ask the office which rules apply to your plan. Phone 208-472-2900.
Middleton	Allowed with conditions	Under 5-4-1, units are capped at 1,000 sq ft; ask how the office measures floor area and whether 5-4-2 applies. Phone 208-585-3133.
Mountain Home	Ask first	MHCC 9-7-4 lists no residential ADU use, and 9-9-2 gives no confirmed size cap; ask what applications the city accepts now. Phone 208-580-2091.
Emmett	Ask first	ECC 9-5-2 gives no ADU route or confirmed cap, while 9-6-1 allows one dwelling structure per lot; ask whether your detached unit qualifies. Phone 208-365-6050.
Idaho Falls	Allowed with conditions	11-2-6(N) caps you at 750 sq ft with owner occupancy until January 31, 2027; then 1,000 sq ft or 75 percent of your house, whichever is larger, without owner occupancy. Phone 208-612-8276.
Ammon	Allowed with conditions	Under 10-7-4, units are capped at 1,000 sq ft or 75 percent of your house’s above-grade living space, whichever is less; ask how the office measures floor area. Phone 208-612-4000. Source: City of Ammon: regulations for accessory dwelling units (Title 10 Chapter 7 Section 4)
Pocatello	Allowed with conditions	Under 17.06.100, units are capped at 750 sq ft with owner occupancy by deed restriction; the house height limit blocks the two-story Rabbit 1000 behind a one-story house. Phone 208-234-6184.
Chubbuck	Allowed with conditions	18.10.040 caps units at 1,000 sq ft; specified zones require owner or close relative occupancy by deed restriction; ask whether modular units qualify. Phone 208-239-3252.
Rexburg	Allowed with conditions	RDC 3.08.010, 4.00.025 has no size cap but requires a hearing and owner occupancy; ask how state law applies to your project now. Phone 208-359-3020.
Blackfoot	Allowed with conditions	11-4A-7.A.20 caps units at 1,000 sq ft; owner or close relative occupancy by deed restriction applies; ask how the office measures floor area. Phone 208-785-8600.
Twin Falls	Allowed	10-6-10.B caps units at 1,000 sq ft or 75 percent of your house’s living space, whichever is larger; owner occupancy is unnecessary, with water and sewer through your house. Phone 208-735-7267.
Jerome	Ask first	Title 17 has no ADU section or size cap; ask how applications proceed and how 17.18.030‘s accessory height limit applies to your unit. Phone 208-324-8189.
Burley	Allowed	5-5-1, 5-6-1, 5-7-1, 5-7A-1 have no size cap or owner-occupancy requirement; your unit in R-1 may reach two stories or 30 ft. Phone 208-647-7086.
Hailey	Allowed	Updated 17.08D has no size cap or owner-occupancy requirement; if you rent one unit short-term, the other’s rentals must last at least 31 days. Phone 208-788-9815.
Ketchum	Allowed with conditions	16.03.040.B.4, 16.04.080 cap net living space at 1,200 sq ft; you cannot sell separately, and 5.09 still requires a short-term rental permit. Phone 208-726-3841.
Driggs	Allowed with conditions	LDC Art. 8.3, Sec. 10.8.2 caps heated area at 700, 1,000 or 1,200 sq ft by zone; ask how the office measures floor area. Phone 208-354-2362.
Coeur d’Alene	Allowed with conditions	17.06.660.G caps units at 800 sq ft or 75 percent of your house, whichever is less; owner occupancy applies only for short-term rentals; ask what applies now. Phone 208-769-2274.
Post Falls	Allowed with conditions	18.20.030 caps units at 1,000 sq ft or half your house’s living area, whichever is less; the owner must live on the property; ask what applies now. Phone 208-773-8708. Source: Post Falls Municipal Code Section 18.24.030 (accessory dwelling units)
Hayden	Allowed	11-2-5.A caps units at 1,000 sq ft; ask how the office measures floor area and applies the height setbacks in 11-2-3 note 1. Phone 208-209-2022.
Rathdrum	Ask first	The online code could not be read, leaving size and occupancy rules unknown; ask which population figure determines whether state law covers your project. Phone 208-687-7245. Source: Rathdrum City Code (building department, adopted codes)
Sandpoint	Ask first	9-1-8.B caps site-built units at 900 sq ft; ask whether your modular unit qualifies and which population figure determines state-law coverage. Phone 208-263-3370.
Lewiston	Allowed with conditions	37-131.2 caps units at 600 sq ft or 30 percent of your house’s habitable area, whichever is larger, never above 900; ask whether the state’s floor applies now. Phone 208-746-1318.
Moscow	Allowed with conditions	Under 3-5.A, units are capped at 600 sq ft or 40 percent of your house, whichever is less, with owner occupancy by deed restriction; ask for current text. Phone: Moscow City Hall.
McCall	Allowed with conditions	3.8.11.01 caps units at 1,500 sq ft; short-term rentals require owner occupancy or a local housing deed restriction. Phone 208-634-4168.

Rules on unincorporated county land

The state ADU law does not bind county land. Each county’s code decides; most make lot size, septic and well capacity central to approval, with health district review separate from zoning.

County (unincorporated)	Detached ADU	What the local rule says
Ada County Hidden Springs, Bogus Basin Road, Kuna and Eagle outskirts	Allowed with conditions	8-4-23 caps size at 1,200 sq ft or 60 percent of your house’s above-ground living space, whichever is less, with owner occupancy by deed restriction; ask whether 24 ft height applies. Phone 208-287-7900.
Canyon County Melba outskirts, Sunny Slope, Lake Lowell, Greenleaf and Notus area	Allowed with conditions	07-10-27, 07-14-25 have no size cap; you must live on site and obtain health approval, plus conditional use approval in R-2. Phone 208-402-4164.
Elmore County Pine, Featherville, Prairie, Mayfield, Hammett	Allowed with conditions	7-2-96 caps units at 900 sq ft; ask whether the 24 ft accessory height applies, and take septic questions to Central District Health. Phone 208-587-2142.
Gem County Sweet, Ola, Montour, Letha, Emmett outskirts	Allowed with conditions	11-6-5.L caps units at 1,800 sq ft; a deed restriction bars separate sale; ask whether the accessory building rule blocks the two-story Rabbit 1000. Phone 208-365-5144.
Boise County Idaho City outskirts, Garden Valley, Lowman, Horseshoe Bend outskirts	Allowed with conditions	Table 4.1.D.3 caps units at 1,000 sq ft on 2.01 to 4 acres; no size cap applies from 4.01 acres; ask how the office measures floor area. Phone 208-392-2293.
Valley County Donnelly area, Lake Fork, Yellow Pine, Smiths Ferry, McCall and Cascade outskirts	Allowed with conditions	9-4-7 caps units at 1,000 sq ft or half your house, whichever is less; the owner must live on the property; ask how the office measures floor area. Phone 208-382-7115.
Blaine County Sun Valley and Ketchum outskirts, East Fork, Croy Canyon, Triumph, Picabo, Carey outskirts	Allowed with conditions	9-3-11 caps units at 1,200 sq ft measured outside walls and requires septic approval; ask how Walker porches count. Phone 208-788-5570.
Custer County Stanley outskirts, Clayton, Mackay and Challis outskirts	Ask first	Art. VII has no size cap; ask the office about your district’s approval chart, Art. XI zoning certification and the health district’s septic step. Phone 208-879-6894. Source: Custer County Zoning Ordinance 2007-09 with amendments as of August 2026
Lemhi County Salmon outskirts, Leadore, North Fork, Tendoy, Elk Bend	Allowed with conditions	Ch. 7 Tables A.1, A.2 have no size cap; your second dwelling needs health district sewage approval. Phone 208-742-1703.
Bonneville County Swan Valley, Irwin, Palisades, Idaho Falls and Ammon outskirts	Ask first	Secs. 156.146 to 156.207 give no ADU route or size cap; ask about permission, Sec. 156.153’s wall height and health district water and septic review. Phone 208-524-7920.
Bannock County Pocatello bench, Inkom, Lava Hot Springs and McCammon outskirts, Arimo area	Allowed with conditions	Sec. 401.H has no size cap, but a deed restriction bars renting or occupancy for gain; RR requires 5 acres with well and septic. Phone 208-236-7230.
Bingham County Firth outskirts, Moreland, Rockford, Blackfoot outskirts	Allowed with conditions	Sec. 10-7-2 has no size cap but bars separate sale and requires water and septic approval; ask whether your detached unit needs conditional use approval. Phone 208-782-3177.
Madison County Rexburg and Sugar City outskirts, Thornton, Lyman, Archer	Allowed with conditions	109-228 allows 1,500 sq ft or half your house, whichever is larger, on lots below 2 acres; otherwise no cap; Rexburg’s impact area requires owner occupancy; ask about height. Phone 208-359-6207.
Teton County Victor, Driggs and Tetonia outskirts, foothills parcels	Allowed with conditions	3-9-3 caps units at 900 sq ft through 2.5 acres, 1,200 sq ft over 2.5 to 7.5 acres, and 1,500 sq ft from 7.5 acres; you need a Septic Capacity Evaluation. Phone 208-776-8240.
Fremont County Island Park, Macks Inn, Ashton and St. Anthony outskirts	Allowed with conditions	Under Appendix U 1.43, footprint caps rise with lot size from 900 sq ft below half an acre to no cap above 2 acres; ask about the conflicting lot minimum. Phone 208-624-4643.
Bear Lake County Fish Haven, the Idaho-side lake shore, Paris, St. Charles and Montpelier outskirts	Allowed with conditions	Chapter 6.G has no size cap, but a deed bars parcel division; ask whether commercial-use restrictions bar rental, and contact public health about septic. Phone 208-945-2155.
Twin Falls County Kimberly and Filer outskirts, Rock Creek, Hansen area	Ask first	8-12-5.B prohibits backyard residences; family permits have no size cap and require septic review; a one-story rule blocks the two-story Rabbit 1000. Phone: Twin Falls County Planning and Zoning.
Jerome County Jerome outskirts, Hazelton and Eden area	Ask first	The code could not be read, so ask about permission and size caps; septic requires public health permits. Phone: Jerome County Planning and Zoning.
Cassia County Burley outskirts, Albion, Oakley and Malta surroundings	Allowed with conditions	9-9-4(W) caps living area at 1,000 sq ft; a deed restriction bars separate sale; ask how the office measures floor area. Phone 208-878-7302.
Kootenai County Athol area, Bayview, Twin Lakes, Hauser, Harrison, Worley area	Allowed with conditions	8.4.301.B caps units at 1,000 sq ft or half your house, whichever is larger, with septic approval; ask how the office measures floor area. Phone 208-446-1070.
Bonner County Sagle, Hope area, Clark Fork surroundings, Priest River and Priest Lake area, Careywood, Cocolalla	Allowed with conditions	12-490 caps units at 900 sq ft with septic approval and 20,000 sq ft lots for detached stand-alone units; ask who inspects your set. Phone 208-265-1458.
Latah County Deary, Genesee and Troy outskirts, Potlatch area, Moscow area of city impact	Allowed with conditions	9-3A-3.A caps units at 900 sq ft or half your house, whichever is less; a deed restriction ties the unit to your parcel; ask about height. Phone 208-883-7220.
Nez Perce County Lapwai area, Lewiston Orchards outskirts, Waha, Culdesac and Peck surroundings	Allowed with conditions	110.16.060 caps units at 700 sq ft or 30 percent of your house, whichever is larger, with septic approval; ask whether 102.04.090 applies. Phone 208-799-3089.

State law requires bound cities to allow detached ADUs; most still print older limits pending updates. Ask first in Garden City, Mountain Home, Emmett, Jerome, Rathdrum, Sandpoint, and Custer, Bonneville, Twin Falls and Jerome counties. Sandpoint’s code says site-built, so ask about a modular unit first. Garden City’s, Rathdrum’s and Jerome County’s code text could not be read.

Ask About My Lot

How big can your ADU be?

Updated bound-city codes cannot cap ADUs below 1,000 sq ft or 75 percent of the house; which governs is unspecified. No state height or story cap applies. Counties and small towns set caps locally: 500, 600, 700, 800, 900, 1,000, 1,200, 1,500 or 1,800 sq ft, percentages and footprint tiers.

Inside 1,000 sq ft: Mysa 500 and Cabana 500, 497; Sledhaus 500, 580; Cabana 700, 638 or 718; Torrey Flats, 696; Morada 800, 793; Morada 1000, 989. Rabbit 1000 is 1,002 sq ft, 2 sq ft over: ask how the office measures floor area. Walker’s 1,165 sq ft depends on the local cap.

Plan	Size	Rooms	Footprint
Mysa 500	497 sq ft	1 bed, 1 bath	14 ft x 36 ft
Cabana 500	497 sq ft	1 bed, 1 bath	14 ft x 36 ft
Sledhaus 500	580 sq ft	1 bed, 1 bath	14 ft x 45 ft with deck
Cabana 700	718 sq ft	2 bed, 1 to 2 bath	14 ft 6 in x 49 ft 6 in (638 sq ft, 44 ft with one bath)
Torrey Flats	696 sq ft	1 bed, 1 bath	15 ft x 48 ft
Morada 800	793 sq ft	1 to 2 bed, 1 to 2 bath	39 ft x 21 ft
Morada 1000	989 sq ft	1 to 2 bed, 1 to 2 bath	43 ft x 24 ft
Rabbit 1000	1,002 sq ft	2 bed, 2 bath	34 ft 8 in x 14 ft 6 in, two story
Walker	1,165 sq ft	2 bed, 2 bath	42 ft x 27 ft

Irontown ADU plans and Idaho starting prices

These Multi-State Designer Series starting prices apply to Idaho plans designed to the International Residential Code. Modern, Balance and Rustic finishes are priced in your quote.

Mysa 500

497 sq ft · 1 bed, 1 bath · from $142,600

497 sq ft, one bedroom and one bath. From $142,600.

See the Mysa 500 plan

Cabana 500

497 sq ft · 1 bed, 1 bath · from $184,400

497 sq ft, one bedroom, sloped roof. From $184,400.

See the Cabana 500 plan

Sledhaus 500

580 sq ft · 1 bed, 1 bath · from $179,300

580 sq ft, one bedroom, included front deck. From $179,300.

See the Sledhaus 500 plan

Cabana 700

718 sq ft · 2 bed, 1 to 2 bath · from $176,200

638 or 718 sq ft, two bedrooms. From $176,200.

See the Cabana 700 plan

Torrey Flats

696 sq ft · 1 bed, 1 bath · from $193,700

696 sq ft, one bedroom, open kitchen and living room. From $193,700.

See the Torrey Flats plan

Morada 800

793 sq ft · 1 to 2 bed, 1 to 2 bath · from $242,400

793 sq ft, one or two bedrooms. From $242,400.

See the Morada 800 plan

Morada 1000

989 sq ft · 1 to 2 bed, 1 to 2 bath · from $247,700

989 sq ft, flexible bedroom and bathroom layouts. From $247,700.

See the Morada 1000 plan

Rabbit 1000

1,002 sq ft · 2 bed, 2 bath · from $239,400

1,002 sq ft, two stories, two bedrooms. From $239,400.

See the Rabbit 1000 plan

Walker

1,165 sq ft · 2 bed, 2 bath · from $276,800

1,165 sq ft, two bedrooms and two baths. From $276,800.

See the Walker plan

Home price and delivery to Idaho

Multi-State starting prices include the Designer Series home, delivery and standard crane set for the first 250 miles from Spanish Fork. Pocatello, Burley, Preston and Bear Lake are inside that range. Beyond it, approximate extra transportation per load is $200 to Idaho Falls, $1,800 to Boise and $6,200 to Coeur d’Alene.

Nearest townPlanTruckloads (estimated)

Approximate road miles from the factory

Estimated delivery beyond the 250 included miles

Starting price, delivered and set, plus estimated extra miles

Estimate only. Multi-State Designer Series starting price with standard delivery and crane set. Beyond 250 miles the rate is $12.75 per mile per truckload; plans wider than about 15 ft and two-story plans usually ship as two modules, and your quote confirms the count. Foundation, site work, stitch, utilities, permits, fees, engineering, pilot cars and sales tax are not included.

Beyond 250 miles, transportation is $12.75 per mile per truckload, plus a pilot car if required. Single-module plans take one load; bigger plans arrive as two modules on two trucks, stitched on the foundation. Use the calculator’s truckloads selector. Your written quote confirms loads, pricing, finishes, transportation and tax treatment.

Costs not in the home price

These costs come on top of the home price and are quoted by your general contractor, city and county, not MCO.

Site work and grading
Foundation and site engineering
Utility trenches and connections
Module stitching and finishing
Steps, porches, decks and landscaping
Permits and plan review
Impact fees and utility capacity charges
Applicable sales or use tax
Minor transport and set touch-ups

Impact and connection fees stay local. Updated bound-city codes cannot charge an ADU more than another single-family home; no state rule exempts ADUs. Published figures include Ada County Highway District’s $1,934 ADU fee and Coeur d’Alene’s $6,460 sewer capitalization fee. Water and sewer connections can be the largest fee item. Ask your city or county which fees an ADU pays.

Idaho law measures sales tax on a modular building on 55 percent of its sales price (63-3613); appliances and furnishings not built in at the factory are taxed separately. Application to a purchase, including delivery and set, depends on the transaction and appears on the written quote. A modular building on a foundation is real property; the county assessor determines its added value.

Living in, renting and keeping your ADU

Updated bound-city codes cannot require owner occupancy. The ADU statute does not limit long-term rental. Under 67-6539, cities and counties cannot prohibit short-term dwelling rentals or require a licence, permit or owner occupancy for them. Several local codes still print conflicting rules; ask the office.

Local codes outside bound cities decide occupancy. Ada, Canyon and Valley counties require owner occupancy, as do current Post Falls, Star and Moscow codes. Bannock, Bear Lake, Cassia, Gem and Latah print no-rent or no-separate-sale deed restrictions. Read your HOA declaration before ordering; 55-3212 leaves room for reasonable HOA rules.

Plans, permits and inspections

Stamped plans go to your local building department for permits; how factory review applies to your Idaho site is confirmed in feasibility.

Updated bound-city codes use administrative approval without hearings. Fremont County publishes 10 business days; Teton County Limited Use review takes 45 days.
Irontown supplies engineered stamped plans designed for your site’s snow load, wind and any wildfire overlay.
Idaho’s Division of Occupational and Professional Licenses reviews and inspects factory construction under a state program; local departments do not reopen it.
Local departments permit and inspect foundations, utilities, set and stitch. Idaho bars sprinkler requirements for one-family and two-family homes (39-4116(3)).
Complete applicable septic, well, wildfire-overlay and HOA steps. A well-served lot needs its well question answered first.

Irontown’s three project phases

Irontown publishes these phase durations. Local permit review adds time; the city or county sets its schedule. Site readiness and agency requirements can also affect delivery.

Phase 1: Feasibility Review (1 to 2 weeks). Virtual site and route review, budget, building requirements and contractor support. The $2,000 fee applies to the final contract.
Phase 2: Pre-construction Agreement (2 to 3 months). Site visit, detailed planning, limited customization, finish selections and stamped engineered plans.
Phase 3: Construction and Delivery (12 to 16 weeks). Factory construction, shipping and module set, with communication about permit, building or site delays.

What happens on your lot

Your general contractor coordinates the on-site work with Irontown. The contractor sets the site-work schedule.

Prepare and coordinate. Evaluate and prepare the site, obtain permits and coordinate delivery.
Build foundation and utilities. Build the engineered foundation and install utility connections.
Receive and set modules. Prepare access, inspect arriving modules and crane them onto the foundation.
Connect and finish. Join modules, weatherproof seams, finish surfaces and connect and test building systems.
Inspect and hand over. Complete inspections, system testing, punch list and your walkthrough; hand over documents and keys.
Support after move-in. Address warranty issues and help establish maintenance schedules if wanted.

Your general contractor handles the site

A general contractor registered with the state is required for on-site work and prices it separately from the home. Irontown has connections to some general contractors; contact MCO to see whether we can recommend one for your area. Irontown’s feasibility review includes contractor support.

Building ADUs for your clients? Email support@mycozyoutdoors.com to join the MCO contractor network.

How to get started

Choose your plan. Compare floor area, bedrooms and finish series.
Request your quote. MCO includes free zoning guidance, sharing code sections and suggested questions.
Confirm locally. Before ordering, confirm requirements with city or county planning and building offices, and septic and well capacity with the health district.
Start feasibility. Review access, budget, building requirements and contractor support with Irontown.
Plan construction. Complete selections and permits, then coordinate your contractor’s site work with factory construction and delivery.

Visit the Spanish Fork factory

Visit Spanish Fork, Utah, about an hour south of Salt Lake City International Airport, with direct flights from Boise, or three to four hours’ drive from eastern Idaho. Walk finished modules on the line and see the finish series.

Schedule a Factory Visit

Common Questions

Does my city have to allow a detached ADU?

Cities over 10,000 cannot ban ADUs and must approve compliant applications administratively. Code updates are due February 1, 2027, so ask what applies now. Counties and smaller towns follow their own codes. Four cities sit near the population line.

How big can my ADU be?

Updated bound-city codes cannot cap it below 1,000 sq ft or 75 percent of the house. The statute joins the two figures with the word or and does not say which governs. Smaller towns and counties set their own caps; published city rules may still await updates.

Can I rent it out, and must I live on the property?

Updated bound-city codes cannot require owner occupancy, and the ADU statute does not limit long-term rentals. County occupancy and deed restrictions vary. State short-term rental protections conflict with some printed local rules, so ask the office.

What will it cost all in?

Combine your written home and transportation quote with your contractor’s site-work quote and local fee estimates. Foundation, utilities, stitching, permits and applicable taxes add to the home price. There is no single statewide project total.

How long does an Irontown ADU take?

Irontown lists 1 to 2 weeks for feasibility, 2 to 3 months for pre-construction, and 12 to 16 weeks for construction and delivery. Local permit review adds time; site and agency delays can affect the schedule.

Do I need a general contractor?

Yes. A state-registered general contractor handles and separately prices the on-site work. Contact MCO to see whether Irontown’s connections include someone for your area; feasibility includes contractor support.

Rules were read in September 2026. This summary is not legal advice or approval; rules change and local offices decide their application. MCO takes no responsibility for zoning, permits, impact fees, septic approval or code compliance. You are responsible for confirming these matters with city or county planning and building offices and the health department for septic, and obtaining required permits before ordering. MCO strongly recommends contacting those offices and can share code sections and suggested questions.