What a New Detached ADU Costs and Involves in Boca Del Mar
A new detached ADU in Boca Del Mar typically runs $90,000-$220,000, with most projects taking 4-7 months from permit approval to final inspection. Because Boca Del Mar sits in unincorporated Palm Beach County, permits route through the county’s Building Division rather than Boca Raton’s office, a detail that trips up contractors who don’t work here regularly. Call (844) 665-0162 and we’ll walk you through whether your lot qualifies and what the timeline looks like for your specific property.
How We Build a New Detached ADU in Boca Del Mar
We’ve learned that homeowners stay sane during an ADU project when they know exactly what’s happening and when they need to make a decision. Here’s how we sequence a typical new detached ADU in Boca Del Mar.
Stage 1: Feasibility and zoning review (1-2 weeks)
Before we touch paper for permits, we verify your lot coverage, setback lines, and any HOA restrictions that apply to your specific Boca Del Mar neighborhood. Palm Beach County allows detached ADUs on single-family lots in most residential zoning districts, but floor-area ratio limits and utility access vary block by block. You’ll decide at this stage whether you want a compact studio unit (400-500 sq ft) or a full one-bedroom with kitchen and stackable laundry (600-800 sq ft). That choice locks the footprint and drives every cost that follows.
Stage 2: Design development and permit drawings (3-5 weeks)
We produce construction drawings that include structural engineering for wind loads, MEP plans, and impact-rated opening schedules. Because Boca Del Mar’s 1970s-80s housing stock predates current hurricane codes, your new detached ADU must meet today’s Palm Beach County wind-speed requirements from day one, not grandfather to the old home’s standard. You’ll select your exterior finish, window and door package, and roofing material during this phase. We typically spec GAF or CertainTeed shingles, or standing seam metal if you want the longest lifespan against our sun exposure.
Stage 3: Palm Beach County permitting (4-8 weeks)
This is where the jurisdictional reality of Boca Del Mar matters. We file with Palm Beach County’s Building Division, not Boca Raton. Contractors who miss this distinction file wrong, get rejected, and lose weeks. We submit complete packages and track plan review comments weekly. You’ll need to sign off on any utility easement agreements if the ADU sits near property lines or existing service lines.
Stage 4: Site prep and construction (10-16 weeks)
We rough-grade, address drainage (critical here with the shallow water table, often just 2-4 feet down), pour the elevated slab, and frame. CBS block construction with stucco finish is standard for Boca Del Mar, matching the existing neighborhood fabric and meeting code cleanly. You’ll make your interior selections during framing: flooring, cabinetry, countertops, fixtures. We carry Cambria, Silestone, and Caesarstone for countertops, and KraftMaid and Wellborn for cabinetry, so you’re choosing between proven brands, not mystery materials.
Stage 5: Inspections and final walkthrough (2-3 weeks)
Palm Beach County inspects foundation, rough electrical, rough plumbing, framing, insulation, and final. We schedule sequentially to avoid re-inspection fees. You’ll do a punch walk with our project lead, and we don’t consider the job closed until every item is resolved.
The Build Options You’ll Actually Decide Between
Every new detached ADU in Boca Del Mar involves choices that aren’t about “good versus bad” but about how you intend to use the space and for how long. Here’s where homeowners typically pause:
- Stick-built on site versus prefab delivery. Traditional framing gives maximum flexibility for odd lot shapes or custom layouts. Prefab units from brands like Mighty Buildings, Boxabl, or Plant Prefab cut site time dramatically, sometimes by 6-10 weeks, but require crane access and precise foundation prep. Prefab works best on flat, open lots with clear utility routes. We partner with all three brands and can quote both paths.
- Impact-rated windows and doors versus shutters. Palm Beach County requires impact-resistant openings or code-compliant shutters on all new construction. Fixed impact windows cost more upfront but never require deployment before a storm. Colonial or accordion shutters save on initial cost but need manual or motorized closing. For a rental ADU where you won’t be on site during hurricane prep, impact-rated is usually the smarter long-term choice.
- Standard shingle versus metal roof. Architectural shingles from GAF or CertainTeed run 30-40% less than standing seam metal. Metal reflects heat better and lasts 40-60 years against our UV exposure, but the premium only pencils out if you’re holding the property long-term or the ADU roof ties visually to a main home metal roof replacement.
- Electric tankless versus traditional water heater. Tankless saves roughly 8-10 sq ft of floor space in a compact ADU. In Boca Del Mar’s hard water environment, it requires annual descaling maintenance. Traditional tank is simpler and cheaper to replace, but burns more energy and needs a closet or corner allocation.
- Septic tie-in versus sewer connection. Some Boca Del Mar parcels still operate on septic. If your main home is on septic, county code may require a separate system or engineered expansion for the ADU. Sewer connection, where available, adds $3,000-$8,000 but eliminates ongoing septic maintenance and inspection obligations.
What New Detached ADU Costs in Boca Del Mar, FL
New detached ADU construction in Boca Del Mar ranges from $90,000 to $220,000. Most of the projects we quote land between $110,000 and $160,000 for a 500-700 sq ft unit with mid-grade finishes and standard utility connections.
| Cost Factor | Low-End Impact | High-End Impact |
|---|---|---|
| Size (sq ft) | 400 sq ft studio, minimal kitchen | 800+ sq ft with full kitchen, laundry, separate bedroom |
| Foundation conditions | Flat, well-drained lot with sewer access | Shallow water table, fill soil, or septic engineering required |
| Utility extension distance | ADU sits within 30 ft of main home services | Long trenching runs, electrical service upgrade, or water main upsize |
| Material grade | Vinyl windows, standard appliances, laminate countertops | Andersen or Pella impact windows, quartz counters, custom cabinetry |
| Exterior finish match | Standard stucco, basic trim | Architectural detail to mirror main home, decorative pavers, landscape integration |
Our written estimates include permits, plans, foundation, framing, rough and finish MEP, insulation, drywall, flooring, cabinetry, countertops, fixtures, paint, and final cleanup. What typically sits outside the base estimate: utility company connection fees, separate septic engineering, HOA application fees, and any main home electrical service upgrade required to support the ADU load. We flag these during feasibility so you’re not surprised.
What Boca Del Mar Homes Specifically Do to This Job
Boca Del Mar’s identity as an unincorporated island within Palm Beach County, sharing a Boca Raton mailing address but none of its city permitting authority, creates a recurring problem we see on inherited projects. Contractors file with Boca Raton, get a rejection notice two weeks later, and the homeowner loses a month. We file directly with Palm Beach County’s Building Division from the start.
The housing stock itself, built almost entirely in the 1970s and 1980s with concrete block and stucco construction, shapes what we encounter. Original electrical panels from that era, often Federal Pacific or Zinsco, frequently can’t handle the added load of a detached ADU without a service upgrade. Flat and low-slope roofs on the main homes develop chronic ponding; when we coordinate roofing work as part of a full property update, we expect to find degraded plywood decking underneath. The shallow water table, sometimes within two feet of grade, means our slab prep for any new detached ADU in Boca Del Mar includes engineered fill and moisture barrier specification as standard, not optional.
Impact-rated openings are non-negotiable on new construction here. We spec PGT or CGI for impact windows and doors, or we design in code-compliant shutters if the homeowner prefers that path. Either way, the wind-load engineering gets signed off before we pour.
Homeowners often pair a new detached ADU with interior work on the main home. If you’re updating the kitchen while adding the unit, our Kitchen Design & Layout in Boca Del Mar crew can coordinate finishes so the two structures feel related, not accidental. Flooring continuity matters too; our Backsplash, Tile & Flooring in Boca Del Mar team handles material selection across both buildings.
Serving Boca Del Mar, FL - Our Local Coverage Area
We’re based in the Boca Del Mar area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
Frequently Asked - New Detached ADU in Boca Del Mar
From permit approval to final inspection, most new detached ADU projects in Boca Del Mar take 4-7 months. Prefab options can compress the construction phase to 8-12 weeks, but Palm Beach County’s permit review timeline remains the same regardless of build method. Call (844) 665-0162 and we can estimate your specific timeline based on current county review queues.
Yes, absolutely. All new detached ADU construction requires Palm Beach County building permits, plus electrical, plumbing, and mechanical permits. Because Boca Del Mar is unincorporated, permits route through the county, not the City of Boca Raton. We handle the entire submission and inspection scheduling process.
Sometimes, but not often. Many 1970s-1980s Boca Del Mar homes still have original 100-amp or undersized panels. A detached ADU with kitchen, laundry, and HVAC typically requires a 200-amp service or a sub-panel with adequate feeder capacity. We assess this during feasibility and include any upgrade in your estimate if needed.
Not necessarily. A new detached ADU in Boca Del Mar starts around $90,000, while a room addition on your existing structure can start lower if you’re simply extending footprint and tying into existing systems. But detached ADUs offer rental income potential, separate utility metering, and no disruption to your main home’s living space during construction. We can quote both paths if you’re unsure.
We warranty our workmanship for one year from final completion. Material warranties run longer and vary by product: GAF and CertainTeed shingles carry 25-50 year limited warranties, Andersen and Pella windows have 20-year glass coverage, and our quartz and cabinetry brands each carry their own manufacturer guarantees. We register all warranties in your name and provide documentation at closing.
Ready to Talk Through Your Lot in Boca Del Mar?
We’ll walk your property, confirm setback and utility feasibility, and give you a written estimate for a new detached ADU built to Palm Beach County code with materials you choose from our 50+ brand roster. No pressure, no deposit to start the conversation. Call (844) 665-0162 or reach out through our Home Additions & ADU in Boca Del Mar page to schedule.
Groundwork Construction Co. serves Boca Del Mar and surrounding communities from our Fort Lauderdale base. Whether you’re expanding for family, rental income, or future flexibility, our Home Additions & ADU crew handles the full build from foundation to finish.
Written by Raymond Estevez, Owner at Groundwork Construction Co., serving Boca Del Mar and South Florida homeowners.