What’s a New Detached ADU in Hobe Sound, FL Going to Take?
A new detached ADU in Hobe Sound is a standalone living unit built on your property, separate from your main home, complete with its own kitchen, bath, sleeping area, and dedicated utilities. Most builds we handle here run 6 to 10 months from permit approval to final inspection, with costs typically falling between $90,000 and $220,000 depending on size, foundation type, and finish level. If you’re weighing options for your property, call us at (844) 665-0162 and we’ll walk the lot with you to see what’s feasible.
How We Build a New Detached ADU - Start to Finish
We’ve learned that homeowners in Hobe Sound stay calmer when they know exactly what happens when. Here’s how we sequence a typical new detached ADU project.
Stage 1: Feasibility and zoning check (2-4 weeks)
Before we draft anything, we pull Martin County property records and verify your lot’s buildable area against the Coastal Construction Control Line and any HOA covenants. You’ll decide at this stage whether you want a traditional stick-built unit or a prefab path through one of our partners like Abodu or Dvele. We also flag early if your lot sits near the Hobe Sound National Wildlife Refuge boundary, where environmental buffer rules can shrink your footprint or require habitat surveys.
Stage 2: Design and permitting (6-12 weeks)
Our drafting team produces plans that satisfy Martin County’s Development Review Committee, including flood-zone elevation requirements for AE and VE zones. You’ll choose your exterior envelope specs here - impact-rated windows and doors if you’re within a mile of the Atlantic, standard wind-load if you’re farther inland on the mainland side. We handle the permit submission, but you’ll need to approve the final set before we file.
Stage 3: Site prep and foundation (3-6 weeks)
We clear the build pad, bring in fill if needed for flood-zone elevation, and pour either a stem-wall foundation with flood vents or a raised pile foundation for waterfront lots. This is where gopher tortoise habitat surveys can trigger delays if your lot borders refuge land - we’ve seen stop-work orders hit contractors who skipped this step. We don’t skip it.
Stage 4: Shell and systems (8-14 weeks)
Framing, roofing, rough electrical, plumbing, and HVAC go in. You’ll make your material lock-down decisions here: cabinet line (KraftMaid or Wellborn), countertop surface (Silestone or Caesarstone if you’re going quartz), plumbing fixtures (Kohler or Moen), and flooring. We coordinate inspections at rough-in and framing - Martin County inspectors are thorough, and we build in time for re-inspection if they flag hurricane-strapping details on older adjoining structures.
Stage 5: Finish and final (4-8 weeks)
Drywall, paint, trim, fixture install, and appliance hookup. We run a final punch walk with you, then schedule the county’s final inspection and certificate of occupancy. Most homeowners move into their new detached ADU within a week of CO.
The Build Choices That Actually Move Your Price
Every new detached ADU in Hobe Sound involves trade-offs. Here’s where your money goes and what you gain or lose with each decision.
- Foundation type: A standard stem-wall slab on the mainland side runs lower than a raised pile foundation required for flood-zone lots near the Intracoastal Waterway or Jupiter Island corridor. Elevated builds add $15,000-$35,000 but keep you insurable and compliant.
- Construction method: Traditional stick-built gives you maximum customization and integrates cleanly with existing landscaping. Prefab options from Dvele or Mighty Buildings cut 2-4 months off the timeline but require crane access and have less flexibility on exterior finishes.
- Window and door grade: Standard wind-load products work for inland 33455 lots. If you’re east of Bridge Road or on the barrier island, impact-rated Andersen or PGT windows are non-negotiable per code - and add roughly 30% to the envelope cost.
- Kitchen and bath spec: A full Kohler fixture package with Silestone counters lands in the mid-range. Caesarstone or upgraded cabinet hardware pushes higher. We spec to your rental income goals if this ADU is an investment play, or to your comfort standards if it’s for family.
- Utility tie-ins vs. separate meters: Sharing water and electric with the main house saves $4,000-$8,000 in tap fees and trenching. Separate meters let you rent the unit independently but require Florida Power & Light coordination that adds 3-5 weeks.
What New Detached ADU Costs in Hobe Sound, FL
For a new detached ADU in Hobe Sound, most projects we quote fall between $90,000 and $220,000. Here’s what pushes you toward the low or high end of that range.
| Cost Driver | Low-End Impact | High-End Impact |
|---|---|---|
| Size (400-1,200 sq ft) | 400-600 sq ft, compact layout | 1,000+ sq ft, full kitchen + bath + laundry |
| Foundation | Slab on well-drained mainland lot | Elevated pile system, flood-zone lot |
| Utility work | Shared meter, minimal trenching | New separate service, long runs to street |
| Finish level | Builder-grade cabinets, vinyl flooring | Custom cabinetry, tile, quartz counters |
| Permit complexity | Standard Martin County review, no HOA | DRC environmental review, HOA design board, refuge buffer |
A written estimate from us includes the full construction contract, permit fees, and standard finishes. It does not include your appliance package, window treatments, or landscaping restoration - we itemize those separately so you’re not surprised. Want exact numbers for your lot? Call (844) 665-0162 - estimates are free.
Why Hobe Sound Properties Make This Job Different
Hobe Sound isn’t Jupiter. It isn’t Palm Beach Gardens. The fact that this entire town sits inside Martin County - with its legally defended slow-growth policies - changes how every new detached ADU gets built here.
We’ve worked mainland ranch homes off Bridge Road and Donald Ross Road where the 1960s-80s construction means no existing hurricane strapping, so any new detached ADU triggers a tie-down upgrade review on the primary structure. That’s not a dealbreaker, but it’s a cost and timeline factor contractors from Broward often miss.
The salt-air corrosion is real and measurable. Within a mile of the Atlantic or the Intracoastal, we spec stainless or hot-dip-galvanized fasteners, copper flashing instead of aluminum, and impact-rated PGT or CGI windows with marine-grade hardware. Skip this and you’ll see frame corrosion in five years, not fifteen.
Flood zones dominate the map here. AE and VE zones cover most waterfront and near-waterfront parcels, which means elevated foundations, flood vents, and finished-floor heights that satisfy FEMA and Martin County building officials. We’ve seen projects across the county line in Jupiter that wouldn’t pass here.
And then there’s the wildlife refuge boundary. Lots on the north end of Hobe Sound, near the refuge edge, can trigger gopher tortoise habitat surveys that add 4-8 weeks and several thousand dollars. We identify this risk in our first feasibility check, not after breaking ground.
If you’re considering a broader renovation alongside your ADU, many homeowners pair this work with Kitchen Design & Layout in Hobe Sound for the main house, or with Backsplash, Tile & Flooring in Hobe Sound to unify the property’s interior finishes. For the full scope of what we build here, see Home Additions & ADU in Hobe Sound.
Serving Hobe Sound, FL - Our Local Coverage Area
We’re based in the Hobe Sound 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 Hobe Sound
Most new detached ADU projects in Hobe Sound take 6 to 10 months from permit approval to move-in, with permitting itself adding 6 to 12 weeks depending on Martin County’s review queue and whether your lot needs environmental buffer review. Prefab options through our partners can compress the build phase by 2 to 4 months. Call (844) 665-0162 to check current permit timelines for your specific address.
Yes - every new detached ADU in Hobe Sound requires a Martin County building permit, and most also need zoning verification against the Coastal Construction Control Line and flood-zone elevation compliance. If your property has an HOA, you’ll need their design approval before the county will issue permits. We handle both tracks as part of our standard process.
Often yes, but it depends on your existing service capacity and whether Martin County requires septic or sewer tie-in upgrades for the additional bedroom count. Shared electric and water meters are allowed and save money; separate meters give you rental flexibility but require Florida Power & Light approval that extends the timeline. We assess this during our feasibility stage so you know before designing.
Not always - in Hobe Sound, a new detached ADU typically runs $90,000-$220,000, while a room addition or garage conversion can land lower per square foot if you’re not dealing with foundation and utility trenching. But a detached unit gives you rental income potential, privacy, and often higher resale value. We quote both paths so you can compare for your specific property.
Our workmanship warranty covers structural and systems installation for a defined period, and every product we install carries its own manufacturer warranty - GAF or CertainTeed for roofing, Andersen or Pella for windows, Kohler or Moen for fixtures. We provide a written warranty packet at closing with all registration details. Ask us for specifics when we quote your project.
Ready to See What’s Possible on Your Hobe Sound Lot?
A new detached ADU in Hobe Sound is a significant project, but it doesn’t have to be a chaotic one. We’ll walk your property, check zoning and environmental constraints, and give you a written estimate with real numbers - no obligation. Call (844) 665-0162 to schedule your free on-site consultation. Raymond Estevez or a member of our Home Additions & ADU team will meet you there, answer your questions, and map out what a build would look like on your specific lot in Hobe Sound.
Written by Raymond Estevez, Owner at Groundwork Construction Co., serving Hobe Sound and South Florida.