Irontown Modular · Authorized Dealer

Modular ADU Homes in Wyoming

Make room for family or a permitted rental. My Cozy Outdoors is your authorized Irontown Modular dealer and direct point of contact. Irontown brings more than 40 years of building experience and is the seller of record.

Designed to the International Residential Code; set on a permanent foundation
Delivery and crane set included for 250 miles; then priced 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

What Wyoming calls an ADU

Wyoming statute has no ADU definition. Local names include accessory dwelling unit, accessory living quarters, accessory residential unit, accessory housing unit, guest home and guest house. Everyday names include mother-in-law suite, granny flat, casita, carriage house, tiny home and prefab ADU. A local guest house without a kitchen is different.

A modular ADU is built in the factory to the International Residential Code and set by crane on a permanent foundation as real property. Wyoming law calls it a transportable home (W.S. 31-1-101), a modular home built to a residential code, not a mobile or manufactured home. Park models and tiny homes on wheels are different products.

Where can you put a modular ADU in Wyoming?

Start with your city limits or unincorporated county location. MCO advises but takes no responsibility; confirm zoning, permits, fees, covenants and septic with your city, county, DEQ or the State Engineer before ordering.

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.

Wyoming leaves ADU rules to local offices

Wyoming has no state ADU law or statewide residential building code. Zoning is optional for cities and counties; several counties have none. These dwelling rules are local. State requirements cover electrical wiring, septic and well permits, first-sale tax and highway permits.

No state ADU law exists: whether your lot may have a detached ADU, how big, and who lives there are local rules; seven counties have no zoning at all.
No statewide residential code or factory-built housing program exists. Local offices choose their code and module review; without a code, nobody reviews plans or issues occupancy certificates.
The utility may not turn on power to a new service until an electrical wiring permit is issued (35-9-120), by the state electrical inspector or your local office.
A septic system needs a permit from the county’s program or the Department of Environmental Quality before construction (35-11-301); a well needs a State Engineer permit before drilling (41-3-930).
State law calls the factory-built modular home a transportable home under 31-1-101. Fixed to its foundation, it becomes real property.
No Wyoming law overrides recorded covenants. Minimum house sizes, second-dwelling bans and written HOA permission can apply; read the declaration before ordering.

Modular ADU rules inside Wyoming cities

These rows show each city’s code as published in September 2026. With no state ADU law, each city sets its own terms. Where no ADU rule is printed, the row says so and points you to the local office.

City	Detached ADU	What the local rule says
Cheyenne	Allowed with conditions	One detached ADU per lot by administrative approval, capped at 40 percent of the house up to 1,200 sq ft, no taller than the house, with a recorded notice (UDC 5.7.3). Phone 307-637-6282.
Laramie	Allowed with conditions	A detached unit’s footprint may be 40 percent of the house’s footprint or 600 sq ft, whichever is less, 220 to 1,200 sq ft (15.10.030(D)(6)); ask how footprint is measured. Phone 307-721-5207.
Rawlins	Allowed with conditions	No size cap: the unit may not be wider or longer than the house, or taller than 25 ft (19.24.050(D)). Ask whether the 24 ft width rule (19.24.015) applies. Phone 307-328-4500, extension 1014.
Rock Springs	Allowed with conditions	In the R-2 district only: 75 percent of the house up to 800 sq ft, one bedroom, owner occupancy (§ 157.086). Ask about the 24 ft width rule (§ 157.145). Phone 307-352-1540.
Green River	Ask first	The zoning ordinance lists no ADU use, and a second dwelling on a lot needs a special use permit with a council hearing (Section 2.1(A)). Ask Development Services first. Phone 307-872-6140.
Evanston	Allowed with conditions	Capped at 50 percent of the house’s footprint up to 1,200 sq ft; the owner must live on the lot (§24-26.1A). Ask about the 24 ft width rule (§7-52.1(D)). Phone 307-783-6470.
Casper	Allowed with conditions	Conditional use permit with a hearing, R-2 district only (17.32.030 J); an owner or immediate family member must live in one unit. No size cap; ask about the two-story Rabbit 1000. Phone 307-235-8241.
Gillette	Allowed with conditions	One ADU on any residential lot with a house, by zoning and building permit, capped at 800 sq ft (Table b. E); the owner must live in the house or ADU. Phone 307-686-5281.
Sheridan	Allowed with conditions	A rear unit may house only family or employees (Appendix A 10.6), no size cap; the 20 ft accessory height cap (10.8) rules out the two-story Rabbit 1000. Phone 307-675-4226.
Cody	Allowed with conditions	Capped at 75 percent of the house’s living area or 800 sq ft on a lot of 7,000 sq ft or more (10-8-2 A); owner occupancy in RR and R-1 only. Phone 307-527-3482.
Riverton	Ask first	The code has no ADU use, and a stand-alone dwelling needs 24 ft of width and 850 sq ft (17.28.010), which only the Morada 1000 and Walker meet. Ask Community Development. Phone 307-856-2999.
Jackson	Allowed with conditions	Capped at 800 sq ft of habitable floor area on a full-size lot, 500 on a smaller one, 26 ft (6.1.11.B); occupants must be Teton County workers, household or nonpaying guests. Phone 307-733-0440.

Modular ADUs on unincorporated county land

These rows cover unincorporated land. Zoned counties set local rules. Without zoning or building codes, no county rule limits second dwellings; septic, well and electrical permits, floodplain rules and covenants apply. Nobody issues occupancy certificates there. Call the office listed.

County (unincorporated)	Detached ADU	What the local rule says
Uinta County rural Evanston, Lyman, Mountain View, Fort Bridger, Bridger Valley	Ask first	No ADU use exists, so ask Planning whether a second home is possible; every dwelling needs at least 650 sq ft (Ch. 5 Sec. 3.a.(4)), which rules out the smallest plans. Phone 307-783-0318.
Lincoln County Star Valley, Afton area, Alpine, Thayne, Etna, Cokeville, rural Kemmerer	Allowed with conditions	One guest house per lot by Residential Use Permit (7.3), capped as a rental at 800 sq ft up to one acre, 1,000 to five acres and 1,200 above. Phone 307-885-3106.
Sweetwater County rural Rock Springs, Green River, Farson, Wamsutter, Granger, McKinnon	Allowed with conditions	One guest home by zoning permit (5.C.7), up to 1,200 sq ft or 75 percent of the house, whichever is larger; lots need 10,000 sq ft on utilities or two acres. Phone 307-872-3914.
Sublette County rural Pinedale, Big Piney, Marbleton, Boulder, Daniel, Bondurant	Allowed with conditions	One guest house up to 1,200 sq ft, basement included, on two acres or more (Ch. III Sec. 18.p), for family and nonpaying guests; renting it needs a conditional use permit. Phone 307-367-4375.
Teton County rural Jackson, Wilson, Moran, Moose, Kelly, Alta, Hoback	Allowed with conditions	Capped at 1,000 sq ft including basement (6.1.11(B)); workers, family, nonpaying guests; rentals minimum 90 days. Rabbit 1000: ask how the office measures floor area. Phone 307-732-8200.
Laramie County rural Cheyenne, Burns, Pine Bluffs, Albin, Carpenter	Allowed with conditions	Capped at half the house up to 1,200 sq ft (3-1-107 e.); owner must live in the main house; in the LU zone a septic permit and about 10 acres apply. Phone 307-633-4303.
Albany County rural Laramie, Rock River, Centennial, Tie Siding	Allowed with conditions	Capped at 75 percent of house up to 1,200 sq ft (Ch. 6 Sec. 8). Lot minimums vary; RR needs 10 acres, RA five, SLR four. Phone 307-721-2568.
Carbon County rural Rawlins, Saratoga, Encampment, Hanna, Medicine Bow, Baggs	Allowed with conditions	Capped at 1,800 sq ft and at least 20 percent smaller than the house, no taller (Ch. 5 A); permitted on five-acre RRA and FPSR lots, conditional in RD. No building code. Phone 307-328-2651.
Natrona County rural Casper, Bar Nunn, Mills, Evansville, Casper Mountain	Allowed with conditions	Capped at 50 percent of the house or 1,000 sq ft, no taller than the house (4.11.05 A); the owner must live in the main house. Ask how floor area is measured. Phone 307-235-9447.
Converse County rural Douglas, Glenrock, Rolling Hills, Bill, Shawnee	Allowed with conditions	No county zoning or building code limits second dwellings. Ask Special Projects about septic; well and electrical permits, floodplain rules and covenants still apply. Phone 307-358-1990. Source: Converse County Permits and Regulations
Platte County rural Wheatland, Guernsey, Chugwater, Glendo, Hartville	Ask first	No size cap; 8.05.010 O limits the printed ADU route to existing operations on RAM land. Ask Planning about special use permission or rezoning elsewhere. Phone 307-322-1330.
Goshen County rural Torrington, Lingle, Fort Laramie, Yoder, LaGrange, Veteran	Allowed with conditions	No county zoning or building code limits second dwellings. Ask Planning for current septic requirements; well and electrical permits, floodplain rules and covenants apply. Phone 307-532-3851. Source: Goshen County Planning and GIS
Campbell County rural Gillette, Wright, Rozet, Recluse	Allowed with conditions	Footprint capped at 60 percent of house living footprint up to 1,100 sq ft (45.70). Written association or covenant approval applies; otherwise conditional use permission. Phone 307-682-1970.
Sheridan County rural Sheridan, Big Horn, Story, Ranchester, Dayton, Clearmont, Arvada	Allowed with conditions	Capped at 75 percent of house living area up to 800 sq ft, including basements and lofts (Section 20 A). Owner occupancy affidavit and septic documentation required. Phone 307-675-2420.
Johnson County rural Buffalo, Kaycee, Lake DeSmet, Barnum	Allowed with conditions	No county zoning or building code limits second dwellings. Planning handles engineered septic permits; well and electrical permits, floodplain rules and covenants still apply. Phone 307-684-1907. Source: Johnson County Planning and Zoning
Crook County rural Sundance, Moorcroft, Hulett, Pine Haven, Aladdin, Beulah	Allowed with conditions	No county zoning or building code limits second dwellings. Planning handles septic permits; well and electrical permits, a county address and recorded covenants still apply. Phone 307-283-4548. Source: Crook County Planning letter of Nov. 27, 2024 (Zoning and Building Permit Information)
Weston County rural Newcastle, Upton, Osage, Four Corners	Allowed with conditions	No county zoning or building code limits a second dwelling; a DEQ septic permit, the state electrical wiring permit, a well permit and recorded covenants still apply. Phone 307-746-4744. Source: Weston County Planning and Zoning
Niobrara County rural Lusk, Manville, Van Tassell, Node	Ask first	No county size cap; residential lots permit one dwelling, and agricultural parcels under 320 acres need rezoning for a dwelling. Ask Planning and Zoning about classification. Phone 307-334-2211. Source: Niobrara County Planning and Zoning Manual (2019)
Fremont County rural Lander, Riverton, Dubois, Shoshoni, Hudson, Pavillion, Jeffrey City; not the Wind River Reservation	Allowed with conditions	No county zoning or building code limits second dwellings. Planning handles septic permits; well and electrical permits, floodplain rules, county addressing and recorded covenants apply. Phone 307-332-1077. Source: Fremont County Planning Department, Building Codes and Certificates of Occupancy
Park County rural Cody, Powell, Meeteetse, Wapiti, Clark, Ralston, Garland	Allowed with conditions	An accessory housing unit by permit: one on 1 to 4.99 acres, two on 5 or more, smaller than the house, no size cap (Sec. 3.a.(1)); ask about lots under one acre. Phone 307-527-8540. Source: Park County Development Standards and Regulations (2025), Table 4-1 and Chapter 3
Big Horn County rural Basin, Greybull, Lovell, Cowley, Byron, Burlington, Shell, Hyattville	Allowed with conditions	No county zoning or building code limits second dwellings. Land Planning handles development and septic permits; well and electrical permits, floodplain rules and covenants apply. Phone 307-568-2424. Source: Big Horn County Land Planning: Development Application (2026)
Hot Springs County rural Thermopolis, Kirby, Lucerne, Hamilton Dome, Grass Creek	Allowed with conditions	No size cap; short-term rental requires owner occupancy (Sec. 4-10). Ask Planner whether adding a home on agricultural land needs land use change hearings (4-4, 4-5). Phone 307-864-2961.
Washakie County rural Worland, Ten Sleep, Winchester	Ask first	No published size cap; old zoning status remains unresolved. Ask Planner about second-dwelling permits; septic, well and electrical permits, plat notes and covenants still apply. Phone 307-347-6778. Source: Washakie County Subdivision and Development Regulations 2.01

No Wyoming law makes a city or county allow an ADU, so these rows print each code as published. Most cities and the zoned counties print a detached ADU rule with conditions. Seven counties have no zoning at all: Fremont, Big Horn, Converse, Goshen, Johnson, Crook and Weston. Ask first in Green River, Riverton, Uinta, Platte, Niobrara and Washakie counties.

Ask About My Lot

Which ADU sizes fit Wyoming’s local rules?

Wyoming sets no size cap or minimum. Cheyenne allows 40 percent of the house up to 1,200 sq ft. Cody and Sheridan County cap units at 75 percent up to 800 sq ft. Uinta County starts at 650 sq ft, with bedroom additions. Heights and stories are local too.

An 800 sq ft cap fits the plans up to 793 sq ft; 1,000 fits up to 989, and the 1,002 sq ft Rabbit 1000 sits 2 sq ft over, so ask how floor area is measured; 1,200 fits all nine. Under a 75 percent rule a 497 sq ft plan needs a 663 sq ft house.

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

Nine Irontown ADU plans for Wyoming

These are Wyoming Multi-State Designer Series starting prices for Irontown’s ADU 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, 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, one bath, 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, one bath, 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, one or two baths. 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, one bath, open living area. 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 and bathrooms. 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; one or two bedrooms and bathrooms. 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, two baths. 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, two baths, entry options. From $276,800.

See the Walker plan

Home pricing and delivery to Wyoming

The Multi-State starting price includes Designer finishes, module delivery, standard crane and set for the first 250 miles from Spanish Fork. Southwest Wyoming’s Evanston, Green River and Rock Springs are inside that distance. Beyond it, approximate extra transportation per load is $600 to Jackson, $2,300 to Casper, $2,800 to Cheyenne and $4,300 to Sheridan.

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, delivery costs $12.75 per mile per truckload. Single-module plans use one load; bigger plans use two trucks, stitched on the foundation. Use the calculator’s truckloads selector. Your written quote confirms loads, pricing, finishes, transportation and tax treatment. Budget a pilot car if the permit requires it; a winter or windy-season delivery can wait for a weather window.

Costs not in the home price

Your general contractor, city and county quote these additional costs, not MCO; they come on top of the home price.

Site preparation, grading and foundation engineering
Foundation construction
Utility trenches, connections and tap fees
Septic permits, well permits and drilling
Module stitching and finish work
Steps, porches, decks and landscaping
Permits, plan review and applicable housing fees
Applicable taxes
Cosmetic transport touch-ups

Wyoming has no state impact fee law for houses; few local governments charge one. Jackson and Teton County have housing mitigation programs, but their accessory residential units are exempt. Usual charges include valuation-based building permits and plan review where codes exist, local zoning fees, city or district water and sewer connections, septic and well permits, and electrical wiring permits. Ask your city or county which charges an ADU pays.

Wyoming taxes the first sale of a factory-built home, called a transportable home under state law; your written quote shows how tax is handled for your sale (39-15-103). Nightly rentals under 30 days carry the state lodging assessment and any local lodging tax where permitted. A modular ADU on a foundation is real property; the county assessor adds its value to the parcel the year it appears.

Living in your ADU or renting it out

No statewide ADU rule determines owner occupancy, renting or nightly stays; local rules do. Separate sale is a title question because the ADU shares the lot. Covenants and HOAs can bar a second dwelling or rental, so read the declaration before ordering.

Cheyenne requires a recorded notice and dropped owner occupancy in 2026. Sheridan limits residential-district units to family or employees. Teton County requires workforce, family or nonpaying-guest occupancy and rentals of at least 90 days. Hot Springs County permits one detached short-term rental on an owner-occupied parcel.

Plans, permits and site requirements

Stamped plans go to your local building department where one exists. The feasibility review confirms your site’s plan review and inspection path.

Routes vary: building permits, administrative review or conditional use; counties without building codes issue no building permits. Zoning schedules remain local.
Irontown supplies stamped engineered plans for local snow, wind, frost and seismic values under the residential code your city or county adopts.
Wyoming has no state program for factory-built homes, so your building department decides how it reviews the factory-built part; the feasibility review confirms it.
State or local electrical wiring permits precede utility connection. Sprinklers and wildfire requirements apply where local codes require them.
Without sewer, the county or DEQ permits septic first, sized by bedrooms; a household well may serve both homes if nobody pays for water.

Your Wyoming ADU timeline

Irontown’s three phases are below; local permits add time. Since July 2026 a city or county with the residential code must say within 10 business days whether a permit application is complete and decide within 30 days (16-13-102); zoning steps run on the office’s own timetable.

Phase 1: Feasibility Review (1 to 2 weeks). Virtual site and route reviews, budget, schedule, building requirements and contractor support. The $2,000 fee applies to your final contract.
Phase 2: Pre-construction Agreement (2 to 3 months). Site visit, detailed planning, limited customization, local design requirements, interior selections and stamped engineered permit plans.
Phase 3: Construction and Delivery (12 to 16 weeks). Irontown builds, ships and sets the modules, communicating any permit, construction or site delays.

Six steps on your site

Your general contractor handles the on-site work, sets the site schedule and coordinates delivery with Irontown. These are Irontown’s six residential steps; the contractor gives you the timing for each.

Prepare and coordinate. Evaluate and prepare the site, obtain permits and coordinate delivery logistics.
Build the foundation and utilities. Follow the structural engineer’s foundation design and install utility connections.
Receive and set the modules. Prepare access, inspect arriving modules and coordinate crane placement on the foundation.
Join and finish. Connect and weatherproof modules, finish seams and connect and test building systems.
Inspect and hand over. Complete required inspections, system testing, punch list, walkthrough and handover.
Support after move-in. Address warranty issues and help establish maintenance schedules when requested.

Your general contractor handles the site work

A general contractor is required and prices on-site work separately. Wyoming has no state general contractor licence; local licensing or registration applies where required. Irontown has connections to some contractors. Contact MCO about a possible recommendation 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 buy your Wyoming modular ADU

Choose your starting point. Share your location, preferred plan and intended use with MCO.
Confirm locally. MCO advises but takes no responsibility; confirm zoning, permits, fees, covenants and septic with your city, county or DEQ before ordering.
Request your quote. Receive written home pricing and free zoning guidance sharing code sections and suggested questions.
Begin feasibility. Review site access, transportation, budget, building requirements and contractor support with Irontown.
Plan and build. Complete selections and agreements with Irontown, the seller of record; coordinate permits and site work with your contractor.

Visit the Spanish Fork, Utah factory

Walk finished modules and see finish series in Spanish Fork, about an hour south of Salt Lake City International Airport. Approximate drives: Evanston, two hours; Rock Springs, three and a half; Jackson, five and a half; Casper, seven.

Schedule a Factory Visit

Common Questions

Does Wyoming let me put a detached ADU on my lot?

There is no state ADU law. Your city or county sets its own rules. Seven counties have no zoning or building code, but septic, well and electrical permits, floodplain rules and covenants still apply.

How big can my ADU be?

Wyoming sets no statewide size limit. Local rules include 800, 1,000 and 1,200 sq ft caps, percentages of the house and minimum dwelling sizes. Your house size, lot, height limits and the office’s floor-area measurement can change which plans fit.

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

Both questions depend on local rules and covenants. Gillette requires owner occupancy; Teton County limits occupants and requires rentals of at least 90 days. Some places restrict nightly rentals or family occupancy. A rented unit on well water needs its own well permit.

What does a Wyoming modular ADU cost all in?

There is no single project total. Home starting prices begin at $142,600. Add your contractor’s site-work quote, local fees, applicable taxes and transportation beyond the included distance. Your written quote confirms the home, finishes, delivery and truckloads.

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. Permits add time. Your contractor sets the site schedule, and weather can delay transport.

Do I need a general contractor?

Yes. Your contractor handles foundation work, utilities, delivery coordination, stitching and finishing, with a separate quote. Local licensing or registration applies where required. Irontown’s feasibility review includes contractor support; ask MCO whether a recommendation is available for your area.

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.