Irontown Modular · Authorized Dealer

Modular ADU Homes in California

Create room for family or a long-term rental. My Cozy Outdoors is your authorized Irontown Modular dealer and direct contact through move-in. Irontown brings more than 40 years of building experience and is the seller of record.

Built to the California Residential Code with fire sprinklers
Delivery and crane set included within 650 miles
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 a California ADU?

California calls an independent dwelling sharing a home’s lot an accessory dwelling unit, or ADU. A junior ADU occupies up to 500 sq ft inside the main house. Here, tiny home, granny flat, casita and prefab ADU are everyday names; a park model RV or tiny home on wheels isn’t a statutory ADU.

Irontown’s modular ADUs are built in the factory to the California Residential Code, the same code as a site-built house, with CALGreen and fire sprinklers, and come with engineered stamped plan sets. A crane sets your home on a permanent foundation, making it real property.

Where can you build?

State law establishes ADU rights; local rules shape the project. Before ordering, confirm zoning, permits, fees and compliance with city or county planning/building offices, and septic with the health department.

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.

California’s statewide rules

Government Code 66310 to 66342 applies statewide, including charter cities. It requires ministerial approval for qualifying ADUs in residential areas. These standards establish a permit path, not approval for a particular parcel.

Every city and county must allow qualifying ADUs ministerially: completeness within 15 business days, decision within 60 days of completeness (66312, 66317).
Detached units: 800 sq ft by right; local cap floors of 850 for one bedroom, 1,000 for more; ordinance ceiling 1,200 (66323, 66321, 66314).
Detached height floor: 16 ft, or 18 ft in qualifying locations; side and rear setbacks no more than 4 ft (66321(b)(4), 66314(d)(7)).
No ADU owner occupancy requirement; shared-sanitation JADUs require it. Rentals: 30-day minimum mandatory for state-exempt units, locally optional otherwise (66315, 66323(e), 66333(b)).
No impact fees at 750 sq ft or less; above that, fees proportionate to the main dwelling (66311.5(c)).
Your local building department reviews Irontown’s stamped permit plans; inspects foundation, utilities, set and stitch. Factory-built module review is settled per city during Irontown’s feasibility review.

Rules inside city limits

Use the city table when your property is inside city limits. These September 2026 findings identify size limits and local gates. For 16 or 18 ft caps, ask MCO for ridge height and the city how it measures height.

City	Detached ADU	What the local rule says
Los Angeles	Allowed with conditions	Cap 1,200 sq ft, two stories; hillside fire access requirements and coastal permits apply (12.22 A.33). Park and linkage fees exempt. Phone 213-473-3231.
San Diego	Allowed with conditions	Cap 1,200 sq ft, two stories within zone height; coastal permit where applicable (141.0302). Rentals require 31 days; first two ADUs exempt from development impact fees (142.0640). Phone 619-446-5000.
Long Beach	Ask first	IB-PZ-001 lists 800 sq ft, 16 ft; city summary lists 1,200, so ask which applies. Ordinance pending; 21.51.276 no longer applies. Phone 562-570-6194.
Anaheim	Allowed with conditions	Cap 1,200 sq ft subject to accessory limits; 800 by right (18.38.015). Table 4-G (18.04.080.020) could not be read; ask. Base fee about $1,490 in 2018. Phone 714-765-5139.
Santa Ana	Allowed with conditions	Cap 1,000 sq ft, or 800 with a JADU; height 20 ft or two stories (41-194.3). Short-term rentals prohibited; review $1,865. Phone 714-647-5804.
Irvine	Ask first	State standards apply (3-26-1); cap above 1,000 sq ft unpublished. Ask about larger plans and covenant terms; planning deposit $1,500. Phone 949-724-6308.
Riverside	Allowed	Cap 1,200 sq ft; two stories to 30 ft, except RC: one story, 20 ft (19.442.030). Rentals 30 days or more. Phone 951-826-5800.
San Bernardino	Allowed with conditions	Caps 850/1,000 sq ft by bedrooms; height 16 ft, transit exceptions (19.04.030(2)(P)). Rentals 30 days minimum; DCA 25-11 could not be read; ask. Phone 909-998-2300.
Pasadena	Allowed with conditions	Cap 1,200 sq ft, hillside 800/1,000; height generally 18 ft, hillside/visible historic units 16 ft (17.50.275). Rentals 30 days or more; impact exemption through 900 sq ft. Phone 626-744-8321.
Temecula	Allowed with conditions	Cap 1,200 sq ft; height 16 ft with transit exceptions; design must match house (17.23.050). Rentals 30 days minimum; planning $2,232. Phone 951-694-6400.
Palm Springs	Ask first	Cap and height unknown because 93.23.14 could not be read. Ask Planning about size, height, rental terms, fees and slope or thoroughfare architectural review. Phone 760-323-8245.
San Jose	Allowed	City-track cap 1,000 sq ft through 9,000 sq ft lots, otherwise 1,200; heights 18 ft/one story, 25 ft/two (20.80.175). Rentals 30 days minimum (20.80.160). Phone 408-793-5302.
San Francisco	Allowed with conditions	Caps 850/1,000 sq ft by bedrooms; height 18 ft, matching-roof allowance, or 16 ft rear-yard track (207.2). Short-term rentals prohibited; Rent Ordinance applies. Phone 628-652-7300.
Sacramento	Allowed	Local cap 1,200 sq ft with zone height; state track 800, height 18 ft with roof allowance (17.228.105). Local-track short-term rentals possible under 17.228.104. Phone 916-264-5011.
Fresno	Allowed	Published cap 1,400 sq ft or 50 percent of house, whichever greater; height zone limit or 30 ft, whichever greater (15-2754). Rentals 30 days minimum. Phone 559-621-8077.
Oakland	Allowed with conditions	Caps 850/1,000 sq ft by bedrooms; height 20 ft, front/side placement 16 ft (17.103.080). S-9 requires extra parking (17.88.050); rentals 30 days minimum. Phone 510-238-3911.
Bakersfield	Ask first	Guidebook cap 1,200 sq ft, zone height; rentals 30 days minimum. Ask Planning for current rules because 17.65 and HCD’s letter could not be read; application $554. Phone 661-326-3733.
Santa Rosa	Allowed with conditions	Cap 1,200 sq ft; one story 16 ft with exceptions, two stories 27 ft; design match and slope restrictions (20-42.130). Rentals 30 days minimum. Phone 707-543-3200.
Redding	Allowed with conditions	Cap 1,000 sq ft; height 16 ft with transit or larger-setback exceptions; design match and high-fire approval (18.43.140). Rentals 30 days minimum. Phone 530-225-4022.
Truckee	Allowed with conditions	Caps 850/1,000 sq ft under one acre, otherwise 1,200; height 16 ft, exceptions require transit or house setbacks; snow engineering (18.58.025). Rentals 31 days minimum. Phone 530-582-7821.

Rules on unincorporated land

Outside city limits, use county rules. A nearby town name does not establish jurisdiction. Septic, fire access, coastal permits and mountain design loads can affect which plan fits.

County (unincorporated)	Detached ADU	What the local rule says
Los Angeles County Altadena, Topanga, Acton, Antelope Valley	Allowed with conditions	Cap 1,200 sq ft, 25 ft; high-fire units over 800 need two 24 ft access roads; coastal rules apply (22.140.640). Rentals 30 days or more. Phone 213-974-6411.
San Diego County Ramona, Alpine, Fallbrook, Julian, Valley Center	Allowed with conditions	Cap 1,200 sq ft, 25 ft (6156.x.A). Septic needs DEHQ layout approval first; rentals require 31 days; fee waiver ended. Phone 858-694-2960.
Riverside County Idyllwild, Anza, Temecula wine country, Lake Mathews	Allowed with conditions	Published cap 1,000 sq ft, 16 ft (17.294.060); replacement 348.5056 could not be read; ask about possible 1,600 cap. Rentals 30 days or more; septic approval required. Phone 951-955-3200.
San Bernardino County Joshua Tree, Big Bear area, Lake Arrowhead, Wrightwood, Yucca Valley outskirts	Allowed with conditions	Cap 1,200 sq ft, height 18 ft or 20 with matching roof (84.36). Ask whether Rabbit 1000 fits; septic approval required, advanced treatment under half-acre. Phone 909-387-8311.
Kern County Tehachapi area, Kernville, Frazier Park, Lake Isabella	Ask first	Written cap 1,200 sq ft (19.90); county applies state law instead. Ask which height rule applies, generally 16 to 18 ft; septic plan or will-serve letter needed. Phone 661-862-5263.
Ventura County Oak View, Ojai Valley, Somis, Bell Canyon, Piru	Allowed with conditions	Lot-tier caps 850/1,000, 1,200, 1,800 sq ft; coastal 700 pending amendment; height 16 ft with exceptions (8107-1.7.5). Rabbit 1000 needs 20 ft setbacks; rentals 30 days or more. Phone 805-654-2488.
Santa Barbara County Santa Ynez Valley, Orcutt, Los Alamos, Montecito	Allowed with conditions	Caps 850/1,000 sq ft through 15,000 sq ft lots, otherwise 1,200; one story 16 ft, two stories 25 ft (35.42.015). Coastal permit; rentals 30 days or more. Phone 805-568-2090.
San Luis Obispo County Nipomo, Templeton, Cambria, Santa Margarita, Los Osos	Allowed with conditions	Cap 1,200 sq ft (22.30.470); Cambria/Los Osos exclusions and Nipomo septic prohibition apply. Inland height text (22.10.090.C) could not be read; ask. Rentals 30 days minimum. Phone 805-781-5600.
Fresno County Shaver Lake area, Auberry, Clovis outskirts, Sanger area	Ask first	Local size/height caps unknown: 855-N could not be read; ask Planning. Low-water exclusions and separate septic required; no county impact fee (17.90). Phone 559-600-4540.
Sacramento County Carmichael, Fair Oaks, Orangevale, Rio Linda, Arden-Arcade, Antelope	Allowed with conditions	Cap 1,200 sq ft, generally 16 ft; second story needs special permit (5.4.5.B). Ask about repeal outcome; short-term rentals prohibited. Phone 916-874-6141.
Placer County Granite Bay, Loomis area, Auburn area, Newcastle, Meadow Vista, North Lake Tahoe	Allowed with conditions	Cap 1,200 sq ft (17.56.200); ask whether rewrite imposes 850/1,200 caps and 16/18 ft heights. Tahoe needs TRPA approval; rentals 30 days or more. Phone 530-745-3000.
El Dorado County El Dorado Hills, Cameron Park, Shingle Springs, Pollock Pines, Georgetown, Meyers	Allowed with conditions	Lot-tier caps 850/1,000, 1,200, 1,600 sq ft; zone height (130.40.300). Rentals 30 days minimum; ask whether conflicting owner-occupancy text is enforced. Phone 530-621-5355.
Nevada County Penn Valley, Lake of the Pines, Lake Wildwood, Alta Sierra, Soda Springs	Allowed with conditions	Cap 1,200 sq ft; zone height, RA/R1 35 ft or three stories (12.03.191). High-fire sites need Fire Protection Plan; rentals 30 days minimum. Phone 530-265-1222.
Santa Clara County San Martin, Los Altos Hills area, Lexington Hills, Stanford lands	Allowed	Cap 1,200 sq ft; house height with house setbacks, otherwise 16 ft with roof allowance (4.10.015). Taller plans need house setbacks; rentals 30 days minimum. Phone 408-299-5700.
Alameda County Castro Valley, San Lorenzo, Ashland, Cherryland, Fairview, Sunol	Allowed with conditions	Caps 850/1,200 sq ft by bedrooms; height 16 ft with transit/roof exceptions; design standards above 800 (17.55). Taller plans need allowance/review; rentals 30 days or more. Phone 510-670-5400.
Contra Costa County Alamo, Discovery Bay, Bay Point, El Sobrante, Kensington, Byron, Bethel Island	Allowed with conditions	Cap 1,000 sq ft, 1,200 on larger/agricultural lots; Kensington 850/1,000 (82-24). Required-yard height 16 to 20 ft; rentals 30 days minimum; planning deposit $2,000. Phone 925-655-2700.
Sonoma County Sonoma Valley, Russian River, Sebastopol area, Penngrove, Larkfield	Allowed with conditions	Inland cap 1,200 sq ft; Z-district exclusion, groundwater limits (26-88-060); coastal 840, 16 ft (26C-325.1). Ask zone height for Rabbit 1000; rentals 30 days minimum. Phone 707-565-1900.
Santa Cruz County Live Oak, Aptos, Soquel, Felton, Ben Lomond, Boulder Creek, Bonny Doon	Allowed with conditions	Caps 850/1,000 sq ft under one acre, otherwise 1,200; urban height generally 16 ft (13.10.681). Rewrite could not be read; ask about outcome; short-term rentals prohibited. Phone 831-454-2580.

Reviewed jurisdictions allow qualifying detached ADUs. Conditions apply except Riverside, San Jose, Sacramento, Fresno and Santa Clara County; ask first in Long Beach, Irvine, Palm Springs, Bakersfield, Kern County and Fresno County. State law applies where codes lag or could not be read. Other cities and the counties of Orange, Marin, Monterey, Solano, San Joaquin, Stanislaus, Tulare, Butte, Shasta, Humboldt, Mendocino, Imperial, Inyo and Mono were not read.

Ask About My Lot

Choose a size that fits the local rules

State law protects an 800 sq ft detached unit. Local caps cannot fall below 850 sq ft for one bedroom or 1,000 for more bedrooms; the statutory ordinance ceiling is 1,200. Most local caps we found are 850, 1,000 or 1,200; some published local texts list higher figures.

Under 800 sq ft: Mysa 500, Cabana 500, Sledhaus 500, Cabana 700, Torrey Flats and Morada 800. Morada 1000 is 989; Rabbit 1000 is 1,002; Walker is 1,165. Rabbit 1000 and Walker exceed 1,000 caps. Heights and stories remain local within state floors; the two-story Rabbit 1000 rarely fits 16 or 18 ft.

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’s California ADU plans

These California Designer Series starting prices include construction to the California Residential Code with CALGreen and fire sprinklers. Modern, Balance and Rustic finishes are priced in your quote.

Mysa 500

497 sq ft · 1 bed, 1 bath · from $157,700

497 sq ft, one bedroom, one bath.

See the Mysa 500 plan

Cabana 500

497 sq ft · 1 bed, 1 bath · from $199,500

497 sq ft, one bedroom, modern sloped roof.

See the Cabana 500 plan

Sledhaus 500

580 sq ft · 1 bed, 1 bath · from $195,300

580 sq ft, one bedroom, included front deck.

See the Sledhaus 500 plan

Cabana 700

718 sq ft · 2 bed, 1 to 2 bath · from $192,800

638 or 718 sq ft, two bedrooms, one or two baths.

See the Cabana 700 plan

Torrey Flats

696 sq ft · 1 bed, 1 bath · from $210,900

696 sq ft, one bedroom, open kitchen and living area.

See the Torrey Flats plan

Morada 800

793 sq ft · 1 to 2 bed, 1 to 2 bath · from $266,600

793 sq ft, one or two bedrooms and baths.

See the Morada 800 plan

Morada 1000

989 sq ft · 1 to 2 bed, 1 to 2 bath · from $274,000

989 sq ft, one or two bedrooms and baths.

See the Morada 1000 plan

Rabbit 1000

1,002 sq ft · 2 bed, 2 bath · from $265,700

1,002 sq ft, two stories, two bedrooms; exceeds 1,000 sq ft caps.

See the Rabbit 1000 plan

Walker

1,165 sq ft · 2 bed, 2 bath · from $304,000

1,165 sq ft, two bedrooms, two baths; exceeds 1,000 sq ft caps.

See the Walker plan

Home price and delivery

The California starting price covers the Designer Series home, California code features, delivery and standard crane set on your foundation for the first 650 miles from Spanish Fork. Included areas encompass the Inland Empire, Los Angeles and Lake Tahoe. San Diego, Sacramento and the Bay Area are beyond that distance.

Nearest townPlanTruckloads (estimated)

Approximate road miles from the factory

Estimated delivery beyond the 650 included miles

Starting price, delivered and set, plus estimated extra miles

Estimate only. California Designer Series starting price with standard delivery and crane set. Beyond 650 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 650 miles, delivery costs $12.75 per mile per truckload, plus pilot cars if required. Single-module plans use one load; bigger plans arrive as two modules on two trucks, stitched on the foundation. The calculator’s truckloads selector adjusts transportation estimates. Your written quote confirms loads, pricing, finishes, transportation and tax treatment.

Costs not in the home price

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

Site work, grading and landscaping
Site engineering and foundation construction
Utility trenches, connections and septic
Module stitching and seam finishes
Steps, porches and decks
Permits and plan check fees
Impact, school and utility connection fees
Sales tax
Transport touch-up allowance

State law exempts ADUs of 750 sq ft or less from impact fees; above that, fees are proportional. School fee relief applies only below 500 sq ft. Proportionate utility connection fees may apply separately. Published figures range from Santa Ana’s $1,865 ADU review fee to San Diego’s approximately $8,085 plan check plus $8,402 inspection. These cover different categories, not total project costs. Ask your city which categories apply.

California’s special sales tax measure for qualifying factory-built housing is 40 percent of the sales price, excluding foundation and site work. Qualification and who collects depend on unit approval and who contracts for the set; your written quote shows tax handling. Irontown’s price excludes sales tax. Your ADU gets its own new assessed value; your main house is not reassessed. A supplemental bill follows.

Family use, rentals and ownership

You can use an ADU for family or long-term rental without living on the property. State law bars ADU owner occupancy requirements; JADUs require it only with shared sanitation. State-exempt ADUs require rentals of at least 30 days. Local ordinances may impose that minimum too.

Most reviewed cities prohibit short-term rentals; San Diego requires 31 days, as does Truckee. Sacramento permits short-term rentals on its local track. Separate sale generally requires a locally adopted condominium route, available in San Diego, or the qualified nonprofit-buyer route under 66341.

Plans, permits and inspections

Your local building department reviews Irontown’s stamped plans for the site permit and inspects the work on your property.

Ministerial review: 15 business days for completeness, 60 days for decision, or 30 with city pre-approved plans; missed deadlines mean deemed approval.
Irontown supplies engineered, stamped plan sets for your site permit.
How your city reviews the factory-built modules is settled with the city during Irontown’s feasibility review and pre-construction phase.
Local inspectors check foundation, utilities, crane set, module stitch, site systems and sprinkler testing.
Septic approval, fire-zone requirements and coastal permits add agency steps where applicable.

Irontown’s three project phases

Local permit review comes on top of Irontown’s phases. Permit, building or site delays can change the schedule. Local agencies set additional septic, coastal and fire-zone timing.

Phase 1: Feasibility Review (1 to 2 weeks). $2,000 applied to the final contract; site and route review, budget, building requirements, schedule and contractor support.
Phase 2: Pre-construction Agreement (2 to 3 months). Site visit, detailed planning, limited customization, local code work, 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, building or site delays.

What happens on your property

Your general contractor coordinates the on-site work with Irontown. The contractor sets the site schedule; Irontown does not publish durations for these steps.

Prepare and permit. Evaluate and prepare the site, obtain permits, coordinate delivery and scheduling.
Build foundation and utilities. Build the engineered foundation and install water, sewer, electrical and gas connections.
Receive and set modules. Prepare access, inspect arriving modules and coordinate crane placement on the foundation.
Join and finish. Connect and weatherproof modules, finish seams, connect and test building systems.
Inspect and hand over. Complete inspections, system testing, punch list and walkthrough; deliver documents and keys.
Support after move-in. Arrange warranty service and maintenance scheduling help when wanted.

Your general contractor handles the site work

A licensed general contractor 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.

Are you a general contractor building ADUs for clients? Email support@mycozyoutdoors.com to join the MCO contractor network.

Start your California ADU project

Share your plans. Tell MCO your location, intended use and preferred ADU plan.
Request a quote. Receive written home pricing and free zoning guidance sharing local code sections and suggested questions.
Confirm locally. Before ordering, confirm zoning, permits, fees and compliance with city or county planning/building offices, and septic with the health department.
Build your site budget. Have your general contractor price foundation, utilities, stitch, finishes and other on-site work.
Begin feasibility. Work through Irontown’s review, pre-construction agreement and final contract before construction and delivery.

Visit the Spanish Fork factory

Visit Irontown’s factory in Spanish Fork, Utah, about an hour south of Salt Lake City International Airport, with direct flights from the main California airports. 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?

State law requires every city and county to allow qualifying detached ADUs on eligible residential lots. The protected 800 sq ft unit has specific height and setback standards. Fire, septic, coastal and other applicable requirements still matter.

How big can my detached ADU be?

State law protects 800 sq ft and sets local cap floors of 850 sq ft for one bedroom or 1,000 for more. The statutory ordinance ceiling is 1,200 sq ft. Local lot tiers, height and story rules affect plan fit.

Can I rent it out without living on the property?

Yes, state law prohibits owner occupancy requirements for standard ADUs. Most reviewed jurisdictions require at least 30-day rentals; San Diego and Truckee require 31. Short-term rental rules vary. A JADU sharing sanitation has an owner occupancy requirement.

What does it cost all in?

There is no single total. California home starting prices run from $157,700 to $304,000. Add your contractor’s site quote, permits, applicable fees, tax and transportation beyond included mileage. The written home quote confirms its scope and charges.

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 is additional. Agencies and your contractor set other timing; delays can affect delivery.

Do I need a general contractor?

Yes. A licensed general contractor handles foundation, utilities, set-day coordination, stitching and finishing, priced separately. Irontown’s feasibility review includes contractor support. Contact MCO to see whether we can recommend a contractor 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.