What a New Detached ADU in Plantation Really Costs and How Long It Takes
A new detached ADU in Plantation typically costs between $90,000 and $220,000, with most projects we build landing around the $140,000 mark for a fully permitted one-bedroom unit with a kitchenette and bath. From the day we break ground to the final inspection, you’re looking at five to seven months, though larger two-bedroom designs with custom finishes can push closer to nine. Call (844) 638-7249 and we’ll walk your specific lot and give you a written, line-by-line number before you commit to anything.
Building a detached accessory dwelling unit on a Plantation lot isn’t like adding a bedroom over the garage. You’re putting a fully independent living space in your backyard, tied to its own foundation, its own electrical panel, and its own sewer lateral. The work touches every trade: site prep, slab or stem-wall foundation, framing, rough-in, drywall, roofing, finishes. The sequence matters a lot, and so does knowing which Broward County plan reviewers want to see what, and when.
How We Build a Detached ADU in Plantation, Start to Finish
Every new detached ADU we build follows the same disciplined sequence. When builders skip steps or rush rough-ins to meet a deadline, that’s when the inspector flags something and the homeowner waits three extra weeks. Here’s exactly how it goes.
Site Survey, Soil Test, and Permit Set
We start with a boundary survey and a geotechnical report. Plantation sits on flat limestone shelf at roughly eight to ten feet above sea level, and the water table here is high enough that the building department requires a soil-bearing-capacity letter before they’ll approve a new foundation. We submit architectural and structural drawings, a site plan showing setbacks from your rear and side lot lines, and the energy compliance forms Broward County expects. Plan review in Plantation typically runs four to six weeks. Once we have the permit card in hand, we order materials and set the excavation date.
Clear, Grade, and Pour the Foundation
Day one of actual site work happens fast. We scrape the building pad, set form boards, and bring in crushed-limestone base to stabilize the slab area. Because the water table can rise after a heavy summer rain, we almost always spec a slightly elevated monolithic slab with turned-down footers rather than trying to pour at grade and hoping the drainage holds. Rebar gets tied, the plumbing stub-ups for your bathroom and kitchenette go in, and we call for the pre-pour inspection. Concrete trucks usually show up two to three days after that inspection clears. The slab cures for seven days before we frame.
Frame, Dry In, and Rough In
Framing a detached ADU of 500 to 800 square feet takes our crew about a week and a half. We stand the walls, set roof trusses, sheath the exterior, and get the structure under a synthetic underlayment fast so rain doesn’t set us back. Then the subs roll through: rough plumbing, rough electrical with a dedicated subpanel, HVAC mini-split lines. The Broward County wind-load requirements mean every strap, clip, and tie-down detail gets photographed before we call the framing and rough-in inspections; inspectors here look for that documentation on any new detached structure, and missing one hurricane clip photo can kick an inspection back a week.
Insulation, Drywall, and Trim
Once the insulation and drywall go up, the ADU starts looking like an actual apartment. This stage runs three to four weeks. We install interior doors, baseboards, window casing, and the kitchenette cabinetry. Your flooring choice matters here too: tile work adds a few days over LVP or engineered wood, but in South Florida’s humidity tile is often the smarter long-term call. We also set the water heater, finish the electrical trim-out, and hang the mini-split indoor unit during this phase.
Finishes, Fixtures, and Final Inspection
The last two weeks are all about the details: paint, backsplash tile, bathroom vanity and faucets, light fixtures, door hardware, exterior siding or stucco to match your main house. We pull together the as-built documentation and schedule the Broward County final inspection, which covers building, electrical, plumbing, and a separate zoning sign-off confirming the structure matches the approved site plan. Once that final is signed, your ADU is legal, insurable, and ready to lease or move family into.
The Options You’ll Choose Between When Building a Detached ADU
Every new detached ADU we design in Plantation starts with the same question: what’s the primary use for this space? The answer determines nearly every spec choice that follows. Here are the decisions that actually move the needle on function and cost.
- Studio versus one-bedroom versus two-bedroom layout. A studio under 500 square feet keeps you at the lower end of the cost range, around $90,000 to $120,000. Adding a separate bedroom with a closet and egress window pushes the footprint past 600 square feet and adds $25,000 to $40,000. Two-bedroom designs run 750 square feet and up, and that’s where you start needing a larger electrical service and a second mini-split zone; $170,000 to $220,000 is realistic.
- Slab-on-grade versus raised stem-wall foundation. A standard monolithic slab works for most flat Plantation lots and costs less upfront. If your yard has even a slight slope toward a canal or drainage easement, or if the soil report shows very loose fill near the surface, we recommend a stem-wall foundation with crawlspace ventilation. That adds $8,000 to $14,000 but keeps the floor assembly dry and the building department happy.
- Kitchenette with or without a gas line. A kitchenette with an electric two-burner cooktop, a small sink, and a compact refrigerator covers most ADU uses. If you want a full gas range, we have to run a buried gas line from the meter, sleeve it through the slab, and add a gas shut-off at the appliance. Trenching and gas rough-in add $3,500 to $6,000, and the inspection sequence gets longer, but for a long-term rental tenant who cooks, it’s often worth it.
- Stucco exterior versus fiber-cement lap siding. Most Plantation homes are CBS with a stucco finish, and matching that on the ADU keeps the whole property looking cohesive and passes HOA architectural review more smoothly. Fiber-cement lap siding, like James Hardie plank, costs about the same installed but reads as a different architectural language. Our recommendation: match what’s already on your main house unless you’re deliberately making the ADU a contrasting style.
- Mini-split HVAC versus tying into the main system. A dedicated ductless mini-split is the standard call for a detached ADU. It’s efficient, it gives the occupant independent temperature control, and it doesn’t require oversized ductwork in a small footprint. Tying into the main home’s central system is almost never practical for a detached structure, and the duct-run distances usually make it more expensive than just installing a separate unit.
What New Detached ADU Costs in Plantation, FL
Plan on $90,000 to $220,000 for a permitted, turnkey detached ADU in Plantation. That range covers everything from a 400-square-foot studio with builder-grade finishes to a 750-plus-square-foot two-bedroom unit with custom cabinetry, a full kitchen, and upgraded flooring. The five variables below explain why one backyard unit lands at $100,000 and the next one down the street hits $200,000.
Square footage is the biggest lever. Every additional hundred square feet adds roughly $18,000 to $25,000 once you account for foundation, framing, roofing, drywall, flooring, and the corresponding bump in electrical and HVAC capacity. A 400-square-foot studio and a 700-square-foot one-bedroom look similar on paper as “a one-bedroom ADU,” but the cost difference is real.
Site access and clearance change the labor equation. A detached ADU built at the rear of a Plantation lot with a narrow side yard means our crew is moving materials by hand or with a compact loader, not backing a full-size skid steer up to the pad. Tight access adds labor hours to excavation, concrete placement, and framing, and it can push the job $5,000 to $10,000 higher than the same design built on a wide, open lot.
Utility tie-ins are a hidden cost. Trenching from the main house’s electrical panel to the ADU, connecting to the existing sewer lateral, and running a new water line each add line-item costs that depend entirely on distance and soil. On a lot where the ADU sits 15 feet from the main house, utility rough-in might run $6,000. At 60 feet, with a driveway crossing to saw-cut and patch, that number can hit $14,000.
Finish level drives the interior budget. Builder-grade cabinets, a standard fiberglass shower insert, and a laminate countertop keep costs down. Custom shaker cabinets, a tiled walk-in shower with a glass enclosure, and quartz or solid-surface counters add $12,000 to $18,000 to the finish package. Both are valid; the question is whether the ADU is for a family member or a market-rate tenant.
Permit and impact fees are set by the city and county. Broward County charges plan-review and permit fees based on the project valuation, and the city of Plantation assesses its own building permit fees and, on new habitable structures, a sewer connection or capacity charge. Those fees together typically run $3,500 to $7,000. We line-item them in your estimate so you see exactly where the money goes.
Your written estimate from us includes the complete scope: site work, foundation, framing, roofing, siding, all rough-ins, drywall, paint, flooring, fixtures, and the final clean. What it doesn’t include, unless we discuss it specifically, are items like landscaping restoration beyond the disturbed construction area, window treatments, or appliance upgrades beyond the contracted kitchenette package. Call (844) 638-7249 for a free on-site estimate with real numbers.
What Plantation Homes Specifically Do to This Job
Plantation was developed as a master-planned community almost entirely between the late 1950s and the mid-1980s, so the housing stock we’re working around is overwhelmingly CBS construction on flat, rectangular lots platted in deliberate phases. When we pull permits for a detached ADU in neighborhoods like Plantation Acres, Jacaranda Lakes, or Lauderdale West, we know three things before we even walk the property. First, the original electrical panel on a house built in, say, 1972 is almost certainly undersized for the additional load of a new dwelling unit, and we’ll need to budget for a service upgrade or a separate meter drop from FPL. Second, the side and rear setbacks on these mid-century plats are generous by South Florida standards, which means an 800-square-foot ADU usually fits without a variance. Third, the Broward County wind-load review for a detached structure under 1,000 square feet is straightforward, but only if the structural drawings show the correct uplift strap schedule and tie-down pattern from the start. Our plans examiner knows the Plantation zoning code well enough that we rarely lose a week on resubmittals, and that alone can be the difference between breaking ground in April and breaking ground in June, right as hurricane-season inspection backlogs start piling up.
Groundwork Construction Co. has been building across South Florida since 2014, and our crews understand Broward County’s middle-ground inspection threshold better than contractors who spend most of their time in Miami-Dade or Palm Beach. Your new detached ADU will meet every Plantation zoning and building code requirement, from foundation elevation to wind mitigation to the final zoning sign-off.
Serving Plantation, FL - Our Local Coverage Area
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Frequently Asked Questions About New Detached ADU in Plantation
Five to seven months from permit issuance to final inspection for a typical one-bedroom unit. The biggest variable is the Broward County plan-review timeline, which runs four to six weeks before we can even break ground. During hurricane season, June through November, inspection availability can tighten and add two to three weeks to the total schedule.
Yes. Any new habitable structure with a foundation requires a full building permit through the City of Plantation and Broward County, including site-plan approval, structural review, and separate electrical, plumbing, and mechanical permits. Building without one risks a stop-work order, fines, and an uninsurable structure. We handle every permit from submittal to final sign-off.
Not entirely, because a detached ADU needs its own water service line run from the meter or the main house supply, a dedicated sewer lateral tie-in, and a separate electrical subpanel. The work is trenching and connecting, not relocating, but it does involve ground disturbance and new underground runs that count as “moving” from an existing-conditions standpoint.
You’re looking at $180 to $280 per square foot, fully finished and permitted, depending on the foundation type, utility-run distances, site access, and the finish level you choose. A basic studio comes in at the lower end; a two-bedroom unit with custom finishes hits the upper end. Call (844) 638-7249 and we’ll give you an exact price for your specific lot.
Everything we build is covered by our 730-Day Done Right Promise. If something isn’t right within two years of completion, we make it right at no cost to you. That covers workmanship across every trade that touched your ADU, from foundation to finish trim.
Get a Free, Line-By-Line Estimate for Your Plantation ADU
You’ll get a written estimate that lists every cost category: site prep, foundation, framing, rough-ins, finishes, and permit fees. No allowances that balloon later, no change orders unless you ask for a scope change. Call (844) 638-7249 to schedule your free on-site estimate for a new detached ADU in Plantation. Derek and our Home Additions & ADU team will walk your yard, answer every question, and hand you real numbers before we leave. This is a big project, and it’s normal to have a lot of questions, which is why we also help homeowners think through how an ADU fits into the bigger picture as part of a full Home Additions & ADU in Plantation plan. Some clients pair the ADU with interior updates like Kitchen Design & Layout in Plantation or Backsplash, Tile & Flooring in Plantation so the main house and the new unit feel equally fresh. We work all over Plantation, and we answer the phone when you call.
Written by Derek Hollenbeck, Owner at Groundwork Construction Co., bringing clear pricing and written warranties to Plantation homeowners since 2014.