What’s a Junior ADU & Interior Conversion in Royal Palm Beach, and What Does It Cost?
A junior ADU & interior conversion in Royal Palm Beach transforms an existing bedroom, den, or underutilized wing of your home into a self-contained living unit with its own kitchenette, full bathroom, and separate entrance, typically without expanding the home’s footprint. Most projects we handle here run 6 to 10 weeks from permit to final inspection, with budgets starting around $45,000 and reaching $130,000 depending on how much plumbing and electrical needs relocation. Call (844) 665-0162 and we’ll walk your floor plan and give you a written, line-item estimate, usually within 48 hours of the site visit.
How We Handle Junior ADU & Interior Conversion from First Walkthrough to Final Inspection
Every junior ADU & interior conversion we build in Royal Palm Beach follows a five-stage sequence. Homeowners who understand the rhythm make faster decisions, and faster decisions keep the permit clock from expiring.
Stage 1: Feasibility and zoning check (3-5 days). We measure the existing space, confirm the bedroom or den can legally convert under Palm Beach County’s junior ADU ordinance, and identify whether your home sits in an HOA with interior-conversion restrictions. Royal Palm Beach has dozens of active community associations, and some covenants restrict secondary-unit square footage or mandate specific exterior door styles for any new entrance. We pull those documents before you spend money on drawings.
Stage 2: Design and permit drawings (2-3 weeks). You’ll decide the kitchenette layout, bathroom configuration, and whether the new unit needs a stackable washer-dryer. We produce permit-ready plans showing electrical load calculations, plumbing riser diagrams, and fire-separation details between the junior ADU and the main residence. Palm Beach County requires these for any dwelling unit with separate cooking facilities.
Stage 3: Demolition and rough-in (2-4 weeks). We remove non-load-bearing partitions, open floors for plumbing drains, and run new electrical homeruns back to a subpanel or upgraded main panel. In Royal Palm Beach’s 1970s-1990s CBS homes, we often find aluminum wiring or undersized panels that need replacement before the county inspector will sign off on additional circuits. This is where the budget can shift, and we flag it during Stage 1 so you’re not surprised.
Stage 4: Finish installation (2-3 weeks). Cabinets, countertops, fixtures, tile, flooring, and the separate exterior door go in. You’ll have already chosen materials by this point. We coordinate inspections for electrical, plumbing, and mechanical roughs before we close walls.
Stage 5: Final inspection and certificate of occupancy (1 week). Palm Beach County building officials verify egress, ventilation, and separation compliance. We don’t hand over keys until the C.O. is recorded. Total elapsed time: typically 6 to 10 weeks, though HOA architectural review can add 2-4 weeks if your community requires it.
The Spec Choices That Shape Your Junior ADU & Interior Conversion
These decisions come up on every job. The trade-offs are real, and we lay them out without steering you toward the most expensive option.
- Kitchenette footprint: full galley vs. wet-bar mini. A 6-foot galley with a 24-inch range and apartment-size refrigerator runs $8,000-$15,000 installed. A wet-bar configuration with a two-burner cooktop, undercounter fridge, and no range hood drops to $4,000-$7,000 but limits what a tenant or family member can cook. Choose based on who will live there and for how long.
- Bathroom scope: tub-shower combo vs. curbless walk-in. Keeping an existing tub-shower and updating surround and valve costs $3,500-$6,500. Converting to a curbless walk-in with linear drain, which we often recommend for aging-in-place junior ADUs, adds $4,000-$8,000 for structural recessing and waterproofing.
- Plumbing routing: surface chase vs. slab penetration. Royal Palm Beach homes are slab-on-grade, so moving a toilet or shower drain means either cutting concrete or building a raised floor platform. Slab cutting is disruptive but preserves ceiling height; a platform costs less in labor but drops headroom 6-8 inches. We show you both paths during the walkthrough.
- Impact-rated exterior door vs. standard fiberglass. If your junior ADU entrance faces the home’s front elevation and your HOA mandates architectural consistency, we may need a specific style, color, and impact rating. Standard fiberglass runs $800-$1,500; impact-rated with HOA-matched panel styling runs $1,800-$3,200. We handle the ARB submittal photos so you don’t get a violation letter.
- HVAC: extended ductwork vs. mini-split. Tapping the main house system is cheaper upfront ($2,000-$4,000) but may overload an aging unit. A dedicated mini-split ($3,500-$6,500) gives the tenant independent control and keeps utility billing separable.
What Junior ADU & Interior Conversion Costs in Royal Palm Beach, FL
Junior ADU & interior conversion in Royal Palm Beach typically costs between $45,000 and $130,000. Here’s what pushes a project toward the low or high end of that range:
| Cost Driver | Low-End Scenario | High-End Scenario |
|---|---|---|
| Existing space size and condition | 400 sq. ft. bedroom with adjacent bath, minimal demo | 800 sq. ft. wing requiring full gut, mold remediation, structural headers |
| Plumbing and electrical relocation | Kitchenette and bath stacked over existing lines | New slab penetrations, 200-amp panel upgrade, sewer ejector pump for below-grade fixtures |
| Material grade | Stock cabinetry, vinyl plank flooring, fiberglass shower surround | Custom cabinets, Silestone or Caesarstone countertops, porcelain tile, Kohler or Moen fixtures |
| Permit and HOA compliance scope | No HOA, straightforward county permit | Full ARB review, impact-door upgrade, drainage impact study for separate meter |
| Separate metering and egress | Shared utilities, existing window meets egress | New electric meter, gas line extension, egress window cut into CBS wall |
A written estimate from us includes demolition, rough and finish carpentry, plumbing and electrical rough-in, fixtures, cabinets, countertops, flooring, paint, and final cleanup. It does not include permit fees (typically $800-$2,200 in Palm Beach County), HOA application fees, or separate utility-meter installation if you choose that route. We itemize every line so you can defer non-essential scope without guessing.
What Royal Palm Beach Homes Specifically Do to This Job
Royal Palm Beach was built out almost entirely between the mid-1970s and late 1990s as a master-planned suburban village, creating an unusually homogeneous cohort of aging CBS homes that are simultaneously hitting the threshold for major construction work. When we bid a junior ADU & interior conversion here, we’re almost always working inside a concrete-block shell with original single-pane aluminum windows, a low-slope tile roof nearing replacement age, and an electrical panel that predates the 2002 Florida Building Code.
That homogeneity creates both efficiency and complication. We know before we arrive that the slab is 4 inches thick, that the wall framing is furring over block, and that we’ll likely need to upgrade from 100-amp to 200-amp service to handle a second kitchen. But we also know the Village of Royal Palm Beach enforces Palm Beach County’s drainage and setback codes strictly, and that any new exterior door or window for the junior ADU must account for the engineered canal-and-retention-pond system that threads through every neighborhood. During wet season, from June through October, we schedule any slab-cutting or exterior penetration work around dry windows to avoid water intrusion into the block cavity.
The pervasive HOA covenants here are the bigger variable. Unlike properties in unincorporated The Acreage, Royal Palm Beach homes often sit under architectural review boards that govern front-door color, style, and even hardware finish. We’ve handled junior ADU conversions in Sherbrooke Estates, Crestwood, and the Original Heights sections where the ARB required us to match existing door profiles exactly, submit paint swatches for approval, and demonstrate that the new entrance wouldn’t alter the home’s street-facing symmetry. We build that compliance work into our timeline and handle the submittals directly, because a stop-work order from an HOA costs more than any material upgrade.
Finally, insurance mitigation is often running parallel to the junior ADU scope. Many homeowners in Royal Palm Beach are already facing Citizens Property Insurance renewal demands for roof-deck clips, impact openings, and truss wrapping. If we’re cutting a new egress window or exterior door for the junior ADU, we coordinate that work with the impact-upgrade path so you’re not paying for two separate mobilizations. Home Additions & ADU in Royal Palm Beach covers the full project spectrum if you’re considering expanding beyond the existing footprint.
Serving Royal Palm Beach, FL - Our Local Coverage Area
We’re based in the Royal Palm Beach 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 - Junior ADU & Interior Conversion in Royal Palm Beach
Most projects take 6 to 10 weeks from permit issuance to certificate of occupancy, plus 2-4 weeks if your HOA requires architectural review. We handle the ARB submittal concurrently with county permit prep so neither sits idle. Call (844) 665-0162 and we’ll check your specific HOA’s typical turnaround.
Yes. Palm Beach County requires a building permit for any dwelling unit with independent cooking facilities, plus separate electrical, plumbing, and mechanical permits. We pull all permits as part of our scope; you never visit the county office. Royal Palm Beach homeowners should also verify whether their HOA requires pre-approval, which we handle.
Sometimes. If your target space has a bathroom on the opposite side of the wall and the kitchenette can stack over existing drain lines, we minimize slab work. But most 1970s-1990s Royal Palm Beach homes need at least electrical panel upgrades and new circuits to meet current code. We map this on day one and show you the exact savings of each layout option.
Typically yes. A junior ADU & interior conversion avoids foundation work, roofing, and exterior weatherproofing, which are the biggest cost drivers in detached construction. Our Home Additions & ADU crew can quote both paths if you’re unsure which fits your lot and budget.
We warranty our workmanship for one year from final inspection, and all materials carry their manufacturer warranties, which range from limited lifetime on cabinets to 10-15 years on fixtures. We register warranties in your name and provide the documentation at closing. For questions about what’s covered, call (844) 665-0162.
Ready to Convert That Extra Space in Royal Palm Beach?
Call (844) 665-0162 to schedule a free, on-site estimate for your junior ADU & interior conversion. We’ll walk the space, check your HOA documents if applicable, and return a written, line-item proposal within 48 hours. No deposit required to start the conversation. Kitchen Design & Layout in Royal Palm Beach is something homeowners often pair with this project if the main kitchen also needs updating, and Small & Partial Kitchen Remodels in Royal Palm Beach works well when the junior ADU kitchenette inspires a refresh of the primary space.
Written by Raymond Estevez, Owner at Groundwork Construction Co., serving Royal Palm Beach since our South Florida founding.