Fast, Reliable New Detached ADU Across Miami Gardens
A new detached ADU in Miami Gardens typically runs $180,000-$310,000 all-in, drawings through final inspection, depending on size, foundation work, and whether you choose a custom build or a prefab system. That includes the HVHZ wind-load engineering Miami-Dade requires, which most national ADU estimates leave out entirely. We’re Ellery ADU Studio, a design-build studio that has delivered 900+ ADUs since 2015, and our Miami Gardens clients get one contract, one written price, and a permit set that actually passes inspection the first time. If you want to know what your rear yard can support, call (971) 497-2402 and we’ll walk the site with you.
Why Ellery ADU Studio Is Miami Gardens’s Preferred New Detached ADU Company
Most Miami Gardens homes are single-story CBS ranch houses built during the Carol City expansion of the 1950s through 1970s. That housing stock has strengths (concrete block holds up well in hurricanes) and complications (original 100-amp panels, galvanized supply lines, and foundations that sit low to a high water table). We know both sides of that equation because we’ve permitted and built detached ADUs throughout Bunche Park, Andover, and the neighborhoods east of Hard Rock Stadium. The city’s wind-load plan review is not something we learn on your project; it’s something we’ve already solved for dozens of homeowners in this exact housing stock.
Our New Detached ADU team carries general liability and workers’ compensation coverage, and the studio’s license is printed on every estimate we issue. We do not hand you a national price sheet. We hand you a written scope with line items matched to Miami Gardens’s actual permit requirements, the HVHZ product specifications, and the foundation approach your lot needs. Under Haven Standard Clause 1, that written price is fixed before any work begins. If the finished ADU doesn’t match the permitted drawings, our 365-Day Done Right Promise applies, in writing.
Our New Detached ADU Services in Miami Gardens
Custom Built ADU
A custom detached ADU in Miami Gardens starts around $220,000 for a 600-square-foot one-bedroom with impact-rated windows, engineered roof straps, and a stem-wall or filled-slab foundation. Every custom build here goes through a separate wind-load plan review with the city, which adds two to four weeks to the permit timeline compared to builds in northern Florida. We produce the full permit set: architectural drawings, structural engineering signed by a Florida-licensed engineer, HVHZ product schedules, and site plans. You get the same drawings the inspector reviews, and we build to them exactly.
Prefab ADU Installation
Prefab systems from Cover, Dvele, and Boxabl can work in Miami Gardens, but only with the right specification. A factory-built unit with standard glazing will fail Miami-Dade’s impact test and trigger a tear-out at first inspection. We spec impact-rated windows and doors at the factory, coordinate the crane or panel delivery on your lot, and supervise the set, utility connections, and final inspection. A one-bedroom prefab ADU in Miami Gardens typically runs $180,000-$240,000 including site work, foundation, and HVHZ-rated envelope. The factory handles the structural core; we handle the compliance, the site, and the permit set under the same contract.
Modular ADU
Modular construction for Miami Gardens lots means the building arrives in sections and gets joined on site. The advantage is speed: once the foundation and utilities are approved, the module set takes days, not months. The compliance requirements do not change. Miami-Dade still requires the engineered roof connections and impact-rated envelope, and any module over 400 square feet goes through the wind-load plan review. For a 2-bed modular ADU in Miami Gardens, budget $210,000-$280,000 depending on the module line and how much site prep your yard needs.
Studio ADU
A studio ADU under 500 square feet is the most cost-efficient path for Miami Gardens homeowners, with builds typically running $150,000-$200,000. These projects move faster through permitting because the simpler roof geometry presents fewer wind-load variables. We’ve built studios in rear yards off Northwest 183rd Street and near the Carol City neighborhoods where a modest footprint still clears the rear setback. One-bedroom and two-bedroom ADUs are our most requested sizes here, but a studio often fits lots where a larger footprint won’t clear the setback without a variance.
What happens when you call
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A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Miami Gardens
We specify and coordinate prefab and modular systems from Cover, Dvele, Mighty Buildings, and Boxabl, and we carry the local product knowledge to make them pass Miami-Dade review. Cover’s steel-framed modules and Boxabl’s compact units both need HVHZ-rated glazing substitutions before they leave the factory, and we write that into the specification so you don’t discover it at rough inspection. Because we coordinate the brand, the permit set, and the construction under one contract, there is no gap where the factory blames the installer and the installer blames the city. You hold one written price, and it includes the compliant product, not a bill for the corrections later.
Common New Detached ADU Problems We See in Miami Gardens Homes
- Standard windows and doors that fail the HVHZ impact test. A national ADU kit with regular glazing will not pass Miami Gardens inspection. The fix is a tear-out, new impact-rated units, and a re-inspection, which adds $8,000-$14,000 and three to six weeks. We spec HVHZ-rated products in the original written price.
- Underestimating the wind-load plan review timeline. Any detached ADU over 400 square feet in Miami Gardens goes through a separate structural review. Homeowners who budget six weeks for permits without accounting for this step end up with a signed contract and no building permit. Our schedule includes the review window from day one.
- Undocumented roof-to-wall connections. Insurance companies after a hurricane claim want evidence the ADU was built to post-Andrew wind codes. If the connection specs were never documented, you have no paper trail. We provide a written record of the engineering, the product numbers, and the inspection sign-offs for your file.
- Original electrical and plumbing that can’t carry the ADU load. Many 1960s Carol City homes still have 100-amp panels and galvanized supply lines. The city won’t release the ADU permit until the panel is upgraded and the supply lines are replaced. We flag these items in the estimate, not after the foundation is poured.
Pricing for New Detached ADU in Miami Gardens, FL
Here is what a detached ADU actually costs in Miami Gardens right now. A studio ADU under 500 square feet runs $150,000-$200,000. A one-bedroom, 600 to 750 square feet, runs $190,000-$260,000. A two-bedroom or two-bath unit typically lands between $240,000 and $310,000. Those are all-in ranges covering drawings, permit fees, foundation, HVHZ-rated windows and doors, engineered roof connections, utility work, and final inspection. What moves the number: whether your lot needs a filled pad or stem-wall foundation for the high water table ($8,000-$18,000), whether the original panel and piping need upgrading ($4,000-$9,000), and which system you choose (custom, modular, or prefab). Every quote we issue is a written line-item price that does not change at signing. Call (971) 497-2402 to schedule a free estimate, and we’ll produce a price for your actual yard, not a range for the national average.
We Also Serve Cities Near Miami Gardens
Our crews serve homeowners across northern Miami-Dade and into southern Broward, including New Detached ADU in Miami Gardens and the surrounding cities of Hialeah, North Miami Beach, Pembroke Pines, and Hollywood. If you’re in one of those cities and weighing a detached ADU, the same written-price standard applies. Call (971) 497-2402 for a free estimate.
Serving Miami Gardens, FL - Our Local Coverage Area
We’re based in the Miami Gardens area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs - New Detached ADU in Miami Gardens
Miami Gardens sits inside Miami-Dade’s high-velocity hurricane zone, which means a detached ADU must meet the structural wind-load requirements of the Florida Building Code’s HVHZ provisions, typically a design wind speed around 175 mph depending on the specific site and roof geometry. That translates to impact-rated windows and doors (large-missile tested), engineered roof-to-wall connections, and a structural plan signed by a Florida-licensed engineer. The city requires a separate wind-load plan review for any ADU over 400 square feet. A compliant quote includes the engineering, the HVHZ product schedule, and the inspection documentation; a cheap quote quietly leaves them out. Call (971) 497-2402 for a written price that includes all of it.
You can, but the math will surprise you. Miami-Dade’s HVHZ permitting treats a carport enclosure as a full structural addition, meaning the enclosed walls and roof system must meet the same engineered wind loads as new construction. The old carport slab and roof framing often can’t be reused, and the resulting budget frequently lands within 10-15% of a ground-up detached unit. We’ll give you an honest side-by-side: the conversion cost, the new-build cost, and a site assessment of what your lot supports. Call (971) 497-2402 and we’ll prepare both numbers before you commit to either.
The three most common are a main panel upgrade from the original 100-amp service to 200 amps, replacement of galvanized supply lines, and a sewer lateral or septic-to-sewer connection depending on where your street falls in the city’s system. On a rear-yard build in Bunche Park, we had to upgrade the original panel and re-pipe the supply lines before the city would release the ADU permit. We installed a one-bedroom Boxabl unit with impact-rated glazing and engineered roof straps rated for HVHZ, and the homeowner received wind-load documentation for their insurance file after final inspection. These upgrades appear in our written estimate, not as a conversation after the city flags them. Call (971) 497-2402 for an exact line-item scope.
Much of Miami Gardens sits on a high water table, which pushes many slab-on-grade ADU designs toward a filled pad that raises the finished floor, or a stem-wall foundation that lifts the structure enough to satisfy flood zone and drainage requirements. The difference is typically $8,000-$18,000 depending on the lot’s elevation certificate and the city’s floodplain determination. A contractor who prices a standard slab without checking the water table will submit a number that won’t hold at permit review. We check the elevation data before we quote, so the foundation line item reflects your actual site. Call (971) 497-2402 for a written price based on your lot, not a template.
Documented compliance can help, because insurers writing policies in Miami-Dade want proof the structure meets post-Hurricane Andrew wind codes before they’ll offer wind mitigation credits or, in some cases, write the policy at all. The documentation matters: engineered wind-load calculations, product numbers for impact-rated windows and doors, and the inspection sign-offs that confirm the roof-to-wall connections were installed as specified. We provide that paper trail as a standard part of every Miami Gardens ADU project. If your existing estimate from another company doesn’t mention the wind-load paperwork you’ll receive, get a free second opinion by calling (971) 497-2402.
Written by Nadia Ellery, Owner at Ellery ADU Studio, serving Miami Gardens with design-build ADU services since the studio’s founding in 2015.