Irontown Modular · Authorized Dealer

Modular ADU Homes in Utah

Make room for family or a long-term tenant with an Irontown backyard home. My Cozy Outdoors, your authorized Irontown Modular dealer, is your contact through move-in. Irontown is the seller of record, with more than 40 years of building experience.

Built to the International Residential Code
Delivery and crane set included within 250 miles
Free zoning guidance with your quote
10 year limited structural warranty

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

What counts as an ADU in Utah?

Utah Code 10-21-101 defines an ADU as a living unit on the same parcel as a single-family home. Internal ADUs sit inside the main home’s footprint for rentals of 30 days or more; detached ADUs stand separately. Tiny home, prefab ADU, casita and backyard home are everyday names here; wheeled homes and RVs differ.

Irontown’s factory-built ADUs follow the International Residential Code, the same residential code as site-built houses. Trucks deliver modules; a crane sets them on a permanent foundation. Once permanently attached, your home is real property. A tiny home on wheels or park model RV is not an ADU under Utah law.

Where can you put a detached ADU?

These summaries reflect codes read in September 2026. A state rule is not a permit. Before ordering, you must confirm zoning, permits, fees and compliance with local planning/building offices, plus septic approval with health officials.

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.

Utah’s statewide rules

Utah Code 10-21-304 takes effect October 1, 2026. Until then, statewide protection covers internal ADUs; detached units depend on zoning. Local building, health and fire requirements remain, as do development agreements signed on or before May 6, 2026.

Coverage: cities with 10,000+ residents, or 5,000 to 9,999 in counties with roughly 40,000+, must allow detached ADUs on qualifying single-family lots of 11,000 sq ft; smaller lots optional.
Local limits: size, height, setbacks, coverage and utility capacity remain local. Cities may require owner occupancy and prohibit rentals under 90 days; no statewide detached size/height cap.
Prohibited: conditional use permits in primarily residential zones; parking above one space below 650 sq ft, two otherwise; design standards conflicting with 10-20-618.
Internal units: 10-21-303 allows residential-zone units with restrictions, including owner occupancy and rentals under 30 days. Title 17 chapter 80 county protections cover internal units only.
Fees: 11-36a-202 exempts internal ADUs within existing homes from impact fees; detached units have no exemption or cap. Local schedules apply; school impact fees are prohibited.
Factory: 15A-1-309 requires approved inspections and modular decals. Under 15A-1-304, local officials permit and inspect foundations, utilities, set and stitch, and verify installation and decals.

Rules inside city limits

These 18 city summaries give you status labels, local section numbers and planning phone numbers. Some codes were changing or unavailable. Confirm current requirements with your city before ordering.

City	Detached ADU	What the local rule says
Salt Lake City	Allowed with conditions	Residential districts: cap 1,000 sq ft (21A.40.200; 21A.33.020). Owner occupancy and covenant required; short-term rentals barred. Phone 801-535-7700.
West Valley City	Allowed with conditions	Residential/agricultural: smaller than house; 11,000 sq ft lots (7-6-201; 7-7-107.5). Owner occupancy required; licensed rentals need 90-day terms. Ask about height. Phone 801-966-3600.
West Jordan	Allowed with conditions	R-1/RR/RE/PC/LSFR/VLSFR: smaller-than-house footprints; 10,000 sq ft platted lots (13-5B-8). Recorded notice and rental license required; rentals minimum 30 days. Phone 801-569-5060.
Sandy	Allowed with conditions	Administrative Special Use Permit (21-11-1); lots 11,000+ sq ft; caps 2,000 sq ft and 75% house footprint; recorded owner affidavit; no rentals under 30 days; two-story plans excluded. Phone 801-568-7100.
Draper	Allowed with conditions	Cap 50% of house floor area (9-31-020; 9-31-040). Owner occupancy required; rentals minimum 30 days. 12,000 sq ft lot minimum unupdated for October 1. Phone 801-576-6399.
Herriman	Allowed with conditions	Single-family zones: cap 1,000 sq ft; 10,000 sq ft lots (10-36-4; 10-36-7). Occupancy affidavit required; licensed rentals minimum 30 days. Phone 801-727-0914.
Ogden	Allowed with conditions	R-1 zones except part of Mount Ogden (15-15-2; 15-13-39): 300 to 800 sq ft; owner occupancy. No October 1, 2026 state rule update was found; cap may change. Phone 801-629-8930.
Layton	Allowed with conditions	Single-family zones: caps 50% house livable space and 1,200 sq ft (19.06.300). Owner occupancy and recorded agreement required; rentals minimum 30 days. Phone 801-336-3780.
Logan	Allowed with conditions	Owner-occupied detached houses: caps 1,000 sq ft and 50% house footprint (17.37.070). Landlord License required; ask rental minimum. Phone 435-716-9000.
Lehi	Allowed with conditions	Chapter 26: lots 11,000+ sq ft, owner-occupied home, outside restricted area map; unit smaller than house; recorded owner-occupancy declaration; ADU and short-term rental permits cannot coexist. Phone 385-201-1030.
Spanish Fork	Allowed with conditions	R-1/R-3/R-R: 6,000 sq ft lots; under one acre, cap 1,000 sq ft living space (15.3.24.090). Owner occupancy required. Phone 801-804-4500.
St. George	Allowed with conditions	Single-family lots: smaller than house (10-17A-3). Owner occupancy, recorded restriction and rental license required; short-term rentals barred. Phone 435-627-4206.
Park City	Allowed with conditions	SF/R-1/Estate: caps one-third of house and 1,000 sq ft (15-2.11-2; 15-4-7). Leases minimum 90 days; nightly rentals barred. Ordinance 2026-19 unavailable; caps uncertain. Phone 435-615-5060.
Cedar City	Allowed with conditions	R-1 cap 800 sq ft (26-III-2); R-E cap 1,200 sq ft (26-III-9); one story. No owner-occupancy rule found in zone text. No October 1, 2026 state rule update was found. Phone 435-865-4519.
Provo	Ask first	Detached ADUs by right only in ADU overlays (14.30.020; 14.30.030); owner occupancy, recorded restriction, annual rental license. As of September 22, 2026, no October 1 state rule update had been adopted. Phone 801-852-6400.
Orem	Ask first	22-6-9: internal apartments only; residential guest houses barred. October 1 draft 22-6-11: proposed 850 to 1,200 sq ft caps, owner occupancy; adoption/numbers unconfirmed. Phone 801-229-7058.
Heber City	Ask first	Notice form: below 1,500 sq ft, owner occupancy, annual rental licensing. Zoning unread; 18.68.060 covers accessory buildings. No October 1 update found. Phone 435-654-0757.
Moab	Ask first	Handout: RA-1/R-1/R-2/R-3/R-4; adopted size rules unread (17.70.030). Type 1 rentals serve active employment households; owner occupancy optional (17.06.020). Likely outside state coverage. Phone 435-259-5129.

Rules on unincorporated county land

The state’s detached ADU rule does not cover unincorporated land. County codes decide. These place names identify areas discussed in the research; your parcel’s jurisdiction matters.

County (unincorporated)	Detached ADU	What the local rule says
Salt Lake County Millcreek-area islands, Magna, Kearns, White City, Emigration Canyon, Copperton, Big and Little Cottonwood canyons	Allowed with conditions	7,000+ sq ft lots in R/A/Forestry/PC zones; owner occupies unit, recorded affidavit; rentals 30+ days. Chapter 19.15 (19.15.030): no size cap; accessory-building total 800 or 1,200 sq ft may apply; ask. Phone 385-910-5600.
Utah County Benjamin, Lake Shore, West Mountain, Elberta, canyon and bench lots	Allowed with conditions	One acre (8.116); cap 1,000 sq ft, or 1,500 with recorded moderate-income rent covenant. Zoning Administrator approval required. No owner-occupancy/rental-term rule found. Phone 801-851-8343.
Davis County Islands around Fruit Heights, Kaysville, Farmington, Hooper and the Antelope Island side	Ask first	Title 15 lacks ADU provisions/state updates. R-1 accessory buildings: cap 1,000 sq ft without dwelling permission; two-family dwellings appear only in AE/R-2. Phone 801-451-3278.
Weber County Ogden Valley, Eden, Huntsville, Liberty, Western Weber, Taylor, Warren, West Weber	Allowed with conditions	Under 108-19: footprint 400 to 1,500 sq ft; floor area maximum 2,000 sq ft. Owner occupancy and recorded notice required; nightly rentals barred. Phone 801-399-8374.
Cache County Cache Valley outside Logan and the towns	Ask first	Definition bars detached units (17.09.030), conflicting with detached permit fee. Attached caps: 50% house and 1,200 sq ft; owner occupancy, 30-day rentals. Phone 435-755-1460.
Washington County Dammeron Valley, Pine Valley, New Harmony, Kolob, Apple Valley area	Allowed with conditions	Caps: 1,500 to 3,500 sq ft (10-13-18). Renting requires owner occupancy and recorded restriction; nightly rentals require limited licensed exception (10-13-23). Phone 435-301-7250.
Iron County Cedar Valley, Enoch area, Parowan Valley, Brian Head area, Kanarraville	Allowed with conditions	Guest houses: administrative permits, no size cap (17.16.030; 17.36.270). Separate rental allowed; short-term rental license required (17.36.290). Foundation-set IRC modular homes allowed (17.16.035). Phone 435-477-8340.
Summit County Snyderville Basin, Kimball Junction, Silver Creek; Eastern Summit around Kamas, Oakley, Coalville, Henefer	Allowed	Listed Basin/Eastern zones; SC conditional (10-2-10; 10-8-5; 11-3-16; 11-6-5). Cap 1,000 sq ft inside walls; no owner-occupancy gate; rentals minimum 30 days. Phone 435-336-3124.
Wasatch County Heber Valley outside Heber and Midway, Timber Lakes, Strawberry, Daniel	Allowed with conditions	Conditional guest ADUs: cap 1,000 sq ft; cannot rent (16.21.46). One acre on sewer/five on septic; caretaker units require ten acres, qualifying staff. Phone 435-657-3205.
Tooele County Erda, Lake Point, Stansbury Park area, Rush Valley, Vernon, Ibapah	Allowed with conditions	Conditional approval (15-5-3.3); cap 1,500 sq ft, no taller than house. Owner lives in main house; recorded notice and minimum 30-day rentals required. Phone 435-843-3100.
Grand County Spanish Valley, Castle Valley area, Thompson Springs	Allowed with conditions	Single-family lots: 5,000 sq ft minimum; unit cap 1,000 sq ft (3.3.2.B). Recorded covenant bars separate sale and stays under 30 days. Phone 435-259-1343.

Sandy and Park City add administrative permits; ask Provo, Orem, Heber City and Moab first. From October 1, covered cities must follow state law despite outdated codes. Unlisted cities and Box Elder, Morgan, Juab, Sanpete, Sevier, Carbon, Emery, Uintah, Duchesne, Kane, Garfield, Wayne, Beaver, Millard, Piute, Rich, San Juan and Daggett counties were not read.

Ask About My Lot

How big can your ADU be?

State law sets no detached ADU size cap. Common local caps are 800, 1,000 and 1,200 sq ft, sometimes relative to your house. Height, setbacks and measurement remain local. At 500 sq ft: Mysa 500 and Cabana 500. At 600 sq ft: add Sledhaus 500; at 700 sq ft: one-bath Cabana 700 and Torrey Flats.

At 800 sq ft: add two-bath Cabana 700 and Morada 800. At 1,000 sq ft: Morada 1000 and Eagle Landing 1000; at 1,200 sq ft: Rabbit 1000 and Walker. Eagle Landing 1220 needs a cap above 1,220 sq ft; its garage may exceed size or footprint limits.

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
Eagle Landing 1000	1,000 sq ft	2 bed, 2 bath	54 ft x 19 ft 8 in
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
Eagle Landing 1220	1,220 sq ft	3 bed, 2 bath	65 ft x 20 ft with attached two car garage

Irontown’s ADU plans

These are Utah Designer Series starting prices. Your quote prices Modern, Balance and Rustic finishes and options.

Mysa 500

497 sq ft · 1 bed, 1 bath · from $137,800

Your living room, kitchen, refrigerator, dishwasher and stacked washer/dryer are included.

See the Mysa 500 plan

Cabana 500

497 sq ft · 1 bed, 1 bath · from $179,700

Your living room opens to a full kitchen; sloped roof and stacked-laundry space.

See the Cabana 500 plan

Sledhaus 500

580 sq ft · 1 bed, 1 bath · from $174,200

You get a private bedroom, full-size kitchen, included front deck and optional loft.

See the Sledhaus 500 plan

Cabana 700

718 sq ft · 2 bed, 1 to 2 bath · from $170,900

You get a full-size kitchen, washer/dryer and bathroom layout choices.

See the Cabana 700 plan

Torrey Flats

696 sq ft · 1 bed, 1 bath · from $188,200

Your open kitchen joins a large living room; living room and bedroom access outdoors.

See the Torrey Flats plan

Morada 800

793 sq ft · 1 to 2 bed, 1 to 2 bath · from $236,100

Your open kitchen, dining and living area includes lounge and bathroom layout options.

See the Morada 800 plan

Morada 1000

989 sq ft · 1 to 2 bed, 1 to 2 bath · from $240,700

You can choose a lounge layout beside open kitchen, dining and living space.

See the Morada 1000 plan

Eagle Landing 1000

1,000 sq ft · 2 bed, 2 bath · from $221,100

Your rambler includes primary suite, porch, pantry and kitchen open to living space.

See the Eagle Landing 1000 plan

Rabbit 1000

1,002 sq ft · 2 bed, 2 bath · from $232,300

Your living space is downstairs, bedrooms upstairs, with covered porch and upstairs deck.

See the Rabbit 1000 plan

Walker

1,165 sq ft · 2 bed, 2 bath · from $268,200

Your big kitchen and dining space offers end or side entry with porch.

See the Walker plan

Eagle Landing 1220

1,220 sq ft · 3 bed, 2 bath · from $260,500

Your garage may exceed ADU caps; a mud room connects it to the kitchen.

See the Eagle Landing 1220 plan

Starting price and your project budget

Utah Designer Series starting prices include finishes, module delivery and standard crane set on your foundation within 250 miles of Spanish Fork. Most of Utah, including Logan and Cedar City, falls within those miles; St. George and Kanab are beyond them. Beyond 250 miles, transportation costs $12.75 per mile per truckload, plus a pilot car if required. Irontown’s transportation coordinator determines additional requirements per quote.

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. Utah 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.

Single-module Mysa 500, Cabana 500, Sledhaus 500, Cabana 700 and Torrey Flats use one load. Bigger plans ship as two modules on two trucks, stitched together on your foundation. The calculator’s truckloads selector multiplies extra miles by $12.75 and estimated loads. Before construction, your written custom quote confirms loads, final pricing, finishes, options, transportation and tax treatment.

Costs not in the home price

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

Site preparation, grading and foundation
Site and foundation engineering
Utility trenches and connections, including septic
Module stitch, interior finishing and exterior finishing
Steps, porches, decks and landscaping
Permits, plan review and applicable impact fees
Sales tax
Transport touch-ups: minor cracks, caulk and door adjustments

Internal ADUs inside existing homes are exempt from impact fees; detached units have no exemption or cap. Spanish Fork reports none; Moab estimates $3,000; West Jordan lists about $17,500 for single-family units, with no ADU category. ADU permit/review charges range from $100 in St. George to $559 in Herriman; building fees are additional. Plan review cannot exceed actual cost or 65% of the building permit fee. Ask about current categories and amounts.

The 45% sales-price exemption under 59-12-104(34) covers new HUD-code manufactured homes, not modular homes. Irontown excludes sales tax; ask the Tax Commission or consult your quote for treatment. No rate/amount is stated here. Permanently attached ADUs are real property assessed with land. Primary residences, including tenants’ primary homes, qualify for the 45% residential exemption; nightly rentals do not. For rentals, file a signed assessor declaration; ask how your county values rented ADUs on owner-occupied parcels.

Family use and renting

Your detached ADU can house family or tenants where local rules allow. State law lets cities require you to occupy either home and bar rentals shorter than 90 days. Many reviewed cities require owner occupancy and a recorded notice or covenant; rental minimums commonly run 30 or 90 days.

State law itself does not ban nightly rentals. St. George and Park City prohibit them; Lehi allows an ADU or short-term rental permit, not both. Moab limits Type 1 tenants to active employment households. Summit County has no owner-occupancy gate; Wasatch County’s detached guest units cannot be rented.

Permits and inspections

Your home needs factory approval and local site approval.

Local building officials permit foundation, installation and utility work; Irontown supplies stamped, engineered plans during pre-construction.
An approved third-party agency inspects factory construction and affixes the state modular decal before shipment.
Local inspectors review foundation, utilities, set and stitch, verify installation against approved documents and check the decal.
Under R317-4, increased septic flow needs health approval; expansion may need changes/permits before work. Unavailable utility capacity can prevent your ADU.
City building review: three business days for completeness, then 14 for plans. Zoning and septic are separate; otherwise local offices set timing.

Irontown’s three project phases

Local permit review is additional. Permit, building or site delays can affect Irontown’s stated schedule.

Phase 1 Feasibility Review (1 to 2 weeks). $2,000, credited to your final contract; site, route, budget, building requirements, schedule and contractor support, including help finding local contractors.
Phase 2 Pre-construction Agreement (2 to 3 months). Site visit, detailed planning, limited customization, interior selections and stamped permit plans.
Phase 3 Construction and Delivery (12 to 16 weeks). Irontown builds, ships and sets your modules.

Six steps on your property

Your required general contractor coordinates on-site work with Irontown, prices it separately from the home and sets the on-site schedule.

Prepare and coordinate. Evaluate and grade your site, obtain permits and coordinate delivery.
Build foundation and utilities. Follow engineered foundation plans and install utility connections.
Receive and set modules. Prepare access and staging, inspect deliveries and coordinate crane placement.
Join and finish. Connect and weatherproof modules, finish seams and connect and test systems.
Inspect and hand over. Complete inspections, testing, punch list and walkthrough; deliver your documents and keys.
Provide ongoing support. Address warranty issues and help with maintenance schedules if wanted.

Your general contractor

You need a licensed general contractor for on-site work, priced separately from your 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 to help find local contractors for site services.

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

How to get started

Describe your project. Share your location, intended use and preferred plan with MCO.
Before ordering, you must confirm zoning, permits, fees and compliance with local planning/building offices, plus septic approval with health officials..
Request your quote. Receive written pricing and free zoning guidance sharing the local rules MCO found.
Begin feasibility. Review delivery access, budget and schedule with Irontown, including contractor support to help find local contractors.
Prepare to build. Complete pre-construction, permits and site preparation with your required general contractor, who prices on-site work separately.

Visit the Spanish Fork factory

Visit 1947 N Chappel Dr, Spanish Fork, UT 84660, about 52 road miles from Salt Lake City and nine from Provo. Schedule a walkthrough of finished modules on the line and see finishes in person.

Schedule a Factory Visit

Common Questions

Does my city have to allow a detached ADU now?

The covered-city requirement begins October 1, 2026, for qualifying single-family lots of at least 11,000 sq ft. Before then, local detached ADU rules govern. Unincorporated county land is outside this requirement.

How big can it be?

State law sets no detached size cap. Cities commonly cap units at 800, 1,000 or 1,200 sq ft, sometimes with an additional limit relative to your house.

Can I rent it, and must I live there?

Local rules decide. Many cities require owner occupancy and rentals of at least 30 or 90 days. Nightly rental permission is separate and often prohibited. Your family use remains subject to local ADU conditions.

What does it cost all in?

Your budget combines Irontown’s written home quote with your general contractor’s site quote, permits, fees and tax. Beyond 250 included miles, delivery is $12.75 per mile per truckload, plus a pilot car if required. Your written quote confirms loads.

How long does it 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 is additional; your contractor sets site timing.

Do I need a contractor?

Yes. A licensed general contractor prices on-site work separately from your 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.

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.