Guide

Using a Container Home as an ADU

A 320 sq ft turnkey container home sits below many ADU maximums, but it does not automatically qualify. Size limits are local. Unincorporated Miami-Dade RU-1 requires at least 400 sq ft, so this unit does not meet that county's ADU minimum. At $47,900 delivered finished in 6–8 weeks, check your county before you order.

Why ADU classification is the useful path

An accessory dwelling unit is a secondary, self-contained dwelling on a lot that already has a primary residence. It is the category most jurisdictions reach for when a unit like ours shows up, and that is good news: ADU review is frequently streamlined, sometimes with pre-approved standards, where a "new dwelling" application would trigger full discretionary review.

ADU rules have loosened considerably. California alone processed roughly 20 times more ADU permits in 2024 than in 2016, and a number of states have since limited how far local governments can restrict them. Whether your own county has adopted matching standards is the thing to verify — see permits and zoning.

How the unit measures against typical ADU standards

The row worth reading twice is minimum floor area. Most people check the maximum and stop. Unincorporated Miami-Dade RU-1 requires at least 400 sq ft, so a 320 sq ft unit does not qualify there. See Miami-Dade's ADU page for the unincorporated (UMSA) rules. Other counties differ. That is a conversation to have with your planner before you order.

What makes this a real dwelling, not a shed

The distinction planners care about is whether the unit is independently habitable. Ours is, and the specifics are what to bring to the counter:

• Full kitchen — refrigerator, 2-burner cooktop, sink, and washer/dryer in one Summit unit
• Full bathroom — Delta EverEdge shower surround, Carrara marble vanity, dual-flush toilet
• Independent climate control — Senville 18,000 BTU dual-zone mini split, heat and cool
• Own electrical service — full 200 amp panel
• Own hot water — Eccotemp i12-NG tankless heater
• R-30 fiberglass insulation (walls & ceilings)
• Its own entrance via a double-pane tempered glass sliding door

Common ADU uses

• Housing a family member. Aging parents or an adult child, close but independent.
• Long-term rental income. See the numbers in rental ROI.
• Short-term rental. Permitted separately from the building permit — verify your local STR ordinance.
• Home office or studio. Genuinely separate from the house, which matters more than people expect.
• Guest accommodation. Without giving up a bedroom the rest of the year.

Cost, all in

The unit is $47,900. Add delivery ($3,810–$13,050 depending on distance from Miami), a foundation, utility hookup, and permit fees. The realistic all-in for an ADU on a site with utilities reasonably close is about $60,000 to $85,000. Full breakdown in what a container home actually costs.

Common questions

Does a 320 sq ft container home qualify as an ADU?

Many jurisdictions allow units this size, but size limits are local. Check your county. Unincorporated Miami-Dade RU-1 requires at least 400 sq ft, so this 320 sq ft unit does not meet that county's ADU minimum. The unit has a full kitchen, full bathroom, independent climate control, and a separate entrance, which ADU classification normally requires.

Do I need a separate utility meter for an ADU?

It varies by jurisdiction. Many allow the ADU to be sub-fed from the primary residence, while others require separate metering. The unit's full 200 amp panel supports either arrangement, so this is a question for your building department rather than a constraint of the home.

Can I rent out an ADU container home?

Long-term rental is generally permitted wherever the ADU itself is permitted. Short-term or nightly rental is governed by a separate ordinance in most places, so verify your local STR rules before ordering if that is the plan.