Building an ADU in Miami-Dade? Here Is the Dumpster You Need for Each Stage
Published October 5, 2026 · Updated October 5, 2026
Most accessory dwelling units (ADUs) in Miami-Dade, whether a garage conversion or a new detached unit in the backyard, start with a 20-yard dumpster for demolition and site prep, then move to a 30-yard or a scheduled swap-out during framing and finishes, as of 2026. The county only allows these units in unincorporated areas inside the Urban Development Boundary, on a lot of at least 7,500 square feet (5,000 for a garage conversion). We rent 20 and 30-yard dumpsters across Miami-Dade and Broward.
What is an ADU and where does Miami-Dade allow one?
- An ADU, accessory dwelling unit, is a second livable unit on the same lot as the main house: an apartment over the garage, a conversion of the existing garage, or a smaller detached structure in the backyard.
- Miami-Dade approved its ADU ordinance in November 2022 and it took effect in 2023, but it only applies in unincorporated parts of the county, inside the Urban Development Boundary, on residential zoning like AU, EU, or RU. Parts of Kendall, Westchester, Palmetto Bay, and Cutler Bay fall into that category. Incorporated cities such as Hialeah, Doral, Coral Gables, or the City of Miami run their own ADU rules, separate from the county's, so confirm with the municipality before you plan the build.
- The minimum lot size is 7,500 square feet for a new ADU, or 5,000 square feet if you are only converting an existing garage. The unit itself runs from 220 to 800 square feet depending on the zoning district, and the owner has to live in either the main house or the ADU as a primary residence; the ordinance does not allow renting it out as a short-term Airbnb.
What size dumpster do I need for each stage of an ADU build?
The construction stage decides the size, not the ADU's finished square footage: a garage conversion generates far less debris than a new unit with its own foundation and slab.
| Stage | Size | Why |
|---|---|---|
| Garage conversion (interior demo) | 20 yard | Drywall, doors, and the old garage floor fit easily, and the container still fits in the remaining driveway |
| Site prep for a new detached unit | 20 yard | Old fencing, a small slab, or backyard vegetation; bulky but light |
| Framing, roof, and drywall | 30 yard, or a 20 with a scheduled swap-out | The lumber and drywall volume from a full new build fills a 20 yard fast |
| Stucco, block, and slab (CBS, the standard Miami build) | Sized by weight, with scheduled swap-outs | Concrete and block hit the truck's legal weight limit before the container is full |
| Final finishes and cleanup | 20 yard | Paint scraps, packaging, and flooring or cabinet trim |
Where does the dumpster go on a lot built for an ADU?
- The 7,500 square foot minimum lot for an ADU doesn't leave much spare room, so the driveway is usually the only practical spot for the container for the length of the job. A 20-yard dumpster needs roughly 22 feet of straight clearance to drop; measure that before you book if the driveway is also staging material for the build.
- Placing it on your own property needs no county permit. If the driveway can't take it and the container has to sit on the street or the swale, Miami-Dade requires a right-of-way permit; see our Miami dumpster permit guide for the process. Being in an unincorporated area for the ADU ordinance doesn't exempt you from an HOA: some Kendall and Cutler Bay communities still restrict container placement, so check your association's rules too; our HOA dumpster guide covers what associations actually enforce.
How is heavy block and concrete debris from an ADU sized?
Most Miami ADUs are built CBS, concrete block and stucco, which is standard for the area's wind code but heavy to haul. Block, stucco scrapings, and slab concrete hit a truck's legal road weight long before a 20 or 30-yard container looks full, so we size that debris by weight and schedule a swap-out instead of overloading one box. Tell us when you book if the stage involves block or a tear-out slab; see our guide to dumpster weight limits in Miami for what concrete and block actually weigh.
How do I time the rental around the county's permitting schedule?
ADU permitting in unincorporated Miami-Dade runs on its own timeline, often several weeks between site plan approval and a framing inspection, so the debris volume rarely stays constant. A standard 7-day rental works for a garage conversion that moves fast, but a new detached unit usually needs scheduled swap-outs timed to the framing and finish stages instead of one container sitting idle between inspections; see our guide to scheduled swap-outs for how we coordinate that with a crew's pace.
FAQ
What is an ADU, and can I build one on my property in Miami-Dade?
An ADU is a second livable unit on the same lot as your house, either a garage conversion or a new detached structure. Miami-Dade allows them only in unincorporated areas inside the Urban Development Boundary, on a lot of at least 7,500 square feet (5,000 for a garage conversion), and the owner must live in the main house or the ADU as a primary residence.
Does Miami-Dade's ADU ordinance apply everywhere, including Hialeah or Coral Gables?
No. The county ordinance covers unincorporated Miami-Dade only. Incorporated cities, including Hialeah, Doral, Coral Gables, and the City of Miami, set their own ADU rules, so check with the municipality before planning the build.
What size dumpster do I need to convert my garage into an ADU?
A 20-yard dumpster handles most garage conversions: the interior demo, old drywall, flooring, and doors fit without filling it, and it still leaves room in the driveway for the rest of the build.
Do I need a permit for the dumpster if my lot is small because of the ADU minimum size?
No county permit is needed if the container sits entirely on your own driveway. A right-of-way permit is only required if it has to go on the street or the swale, which is more likely on a smaller ADU-sized lot.
Can I rent out my Miami-Dade ADU as an Airbnb?
No. The county ordinance requires the owner to live in either the main house or the ADU as a primary residence and sets a one-month minimum rental, which rules out short-term and vacation rentals.
How long do I need the dumpster during ADU construction?
A standard 7-day rental covers a garage conversion. A new detached unit usually spans several weeks across site prep, framing, and finishes, so we schedule swap-outs timed to each stage instead of one container sitting for the whole build.
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