What Does Junior ADU & Interior Conversion Cost and Involve in Ojus?
Junior ADU & Interior Conversion in Ojus, FL typically runs $45,000-$130,000 and takes 8-14 weeks from permit approval to final inspection, depending on whether you’re reconfiguring an existing wing of a 1950s ranch or converting a garage-adjacent space with full kitchen and bath additions. Most Ojus homeowners we work with are converting a portion of a concrete-block ranch home into a self-contained unit for aging parents or rental income, which means dealing with Miami-Dade’s High-Velocity Hurricane Zone requirements from day one. Call (844) 665-0162 and we’ll walk through your specific layout, usually same week.
How We Handle Junior ADU & Interior Conversion Start to Finish
Every junior ADU & interior conversion in Ojus follows a five-stage sequence. We’ve refined this through builds across unincorporated Miami-Dade, where county permits and HVHZ inspections add complexity that out-of-area crews routinely underestimate.
Stage 1: Feasibility and existing conditions survey (Week 1)
We measure the target space, document existing electrical, plumbing, and structural conditions, and verify your property’s zoning allows a junior ADU under Miami-Dade’s unincorporated rules. For Ojus’s 1950s-1970s concrete-block ranches, we’re specifically checking whether original slab conditions can support added wet areas, whether the existing roof structure allows for the separate exterior entrance most junior ADUs require, and whether your electrical panel has capacity for a second kitchen and HVAC zone. You’ll decide at this stage whether to proceed with a full kitchen or a kitchenette, and whether the unit needs independent meter capability.
Stage 2: Design, material selection, and permit prep (Weeks 2-4)
We produce construction drawings showing the new layout, egress paths, and HVHZ-compliant window and door specifications. Material selection happens here: cabinetry grade, countertop surface, flooring type, tile versus solid-surface shower surrounds, and mini-split versus central HVAC extension. For Ojus specifically, every window and exterior door must carry a Miami-Dade Notice of Acceptance (NOA), which narrows the product field considerably compared to Broward County just north. We handle the county permit submission, but you’ll need to approve final fixture selections before filing, since changes post-permit trigger re-review.
Stage 3: Demolition, rough-in, and structural modification (Weeks 5-8)
This is where the existing space gets opened up. We may be removing interior block walls, cutting in the separate exterior entrance, relocating plumbing drains through the slab, and upgrading electrical service. In Ojus, the shallow Miami Limestone beneath most slabs often requires rock-cutting equipment for new drain lines, and we coordinate dewatering if we hit the water table. You’ll make one critical decision here: if we discover moisture intrusion at the slab edge, whether to install perimeter drainage now or address it cosmetically.
Stage 4: Enclosure, finishes, and systems (Weeks 9-12)
Drywall, flooring, cabinetry installation, countertop templating and install, tile work, fixture setting, and HVAC commissioning. We sequence this tightly because Ojus’s humidity demands that interior finishes not sit open to the air longer than necessary. Your paint color and hardware selections get locked in here.
Stage 5: County inspection and punch list (Weeks 13-14)
Miami-Dade Building Department inspectors verify structural, electrical, plumbing, and HVAC compliance. Because Ojus is unincorporated, all inspections route through the county’s centralized queue, which we’ve learned to schedule proactively. Final walkthrough with you, then certificate of completion.
The Material and Configuration Choices That Shape Your Junior ADU
Junior ADU & Interior Conversion in Ojus forces specific decisions that affect daily livability and resale value. Here’s where homeowners typically land:
- Kitchenette versus full kitchen: A kitchenette with a two-burner cooktop, under-counter fridge, and single-bowl sink runs lighter on electrical and plumbing, keeping you toward the $45,000-$75,000 range. A full kitchen with 30-inch range, dishwasher, and full-size refrigerator adds circuits, venting, and cabinet volume, pushing toward $90,000-$130,000. For rental use, the full kitchen recoups faster; for family use, the kitchenette often suffices.
- Cabinetry grade: KraftMaid’s semi-custom lines offer solid wood doors and soft-close hardware at a mid-tier price point with reasonable lead times. Wellborn’s framed construction holds up well in Ojus’s humidity if you select their painted finishes with catalytic conversion varnish. Both brands have NOA-compliant installation hardware for HVHZ applications.
- Countertop surface: Cambria quartz offers the best stain and heat resistance for a rental unit where tenants may not use cutting boards. The trade-off is weight; in some older Ojus slabs with hairline settling, we may recommend a lighter Silestone or Caesarstone profile to reduce point loads.
- Flooring: Luxury vinyl plank handles moisture fluctuations better than engineered hardwood and installs faster, but tile over a properly prepped slab is the most durable long-term solution in this climate. The decision usually hinges on whether the existing slab needs self-leveling compound.
- HVAC strategy: A dedicated mini-split gives the junior ADU independent climate control and avoids overloading a 1970s electrical panel. Extending the main home’s central system is cheaper upfront but creates billing and comfort conflicts.
- Exterior envelope: James Hardie fiber-cement siding matches well with Ojus’s existing block construction when we’re adding the required separate entrance, and it carries HVHZ approval that vinyl alternatives often lack.
What Junior ADU & Interior Conversion Costs in Ojus, FL
Junior ADU & Interior Conversion in Ojus, FL ranges from $45,000 to $130,000. Here’s what moves you through that range:
| Cost Factor | Low-End Impact | High-End Impact |
|---|---|---|
| Size of converted space | 400-500 sq ft kitchenette/bath | 800+ sq ft with full kitchen, separate bedroom, laundry |
| Existing condition | Sound slab, intact roof, modern electrical panel | Moisture-damaged slab edge, asbestos-containing materials, inadequate structural headers |
| Plumbing/electrical relocation | Wet back stays near existing drains | New bathroom cut through slab to opposite side of house; 200-amp service upgrade required |
| Material grade | Stock cabinetry, LVP flooring, standard fixtures | Custom cabinetry, tile throughout, impact-rated architectural windows |
| Permit and inspection scope | Interior renovation with no structural changes | Structural modifications, new exterior door/window cuts, separate utility metering |
A written estimate from us includes demolition, rough and finish carpentry, plumbing and electrical rough-in and trim, HVAC rough and equipment, insulation, drywall, flooring, cabinetry, countertops, tile work, fixtures, paint, and permit fees. It does not include separate utility meter installation, which FPL handles directly, or furniture and window treatments. If your existing roof needs replacement to meet HVHZ requirements for the new exterior opening, that’s a separate line item we’ll flag during the feasibility survey.
Many homeowners exploring this work as part of a full Home Additions & ADU in Ojus project find that tackling the junior ADU first, then the main home kitchen, lets them sequence cash flow and stay in the house throughout. Our Home Additions & ADU crew coordinates both phases if you choose that path.
Why Ojus Properties Make This Job Different
Ojus’s unincorporated status means every junior ADU & interior conversion pulls permits through Miami-Dade County’s Building Department, not a city office. The inspection queue is county-wide, and contractors unfamiliar with this system often mis-file residential accessory dwelling paperwork or underpay fees that an incorporated city like Aventura would handle through its own building department. We’ve seen out-of-area crews lose three weeks to permit corrections that should have been caught at submission.
The housing stock compounds this. Most Ojus homes are 1950s-1970s concrete-block ranches built to pre-Hurricane Andrew standards, many still carrying original single-pane jalousie or aluminum windows and flat or low-slope built-up roofs. Any permitted renovation triggers current HVHZ impact-resistance and wind-load requirements, which turns a straightforward interior conversion into a significant envelope upgrade. That new separate entrance your junior ADU requires? The door and any adjacent window must be NOA-certified products, and the rough opening may need structural reinforcement that wasn’t in the original block wall.
Below grade, the Miami Limestone sitting 1-3 feet down means any new plumbing through the slab requires rock-cutting capability and often dewatering. General earthwork contractors from Central Florida arrive unprepared for this. The porous limestone and shallow water table also explain why we inspect so carefully for moisture intrusion at slab edges; a junior ADU with a new bathroom is the worst place to discover a chronic drainage problem.
We cover Ojus and the surrounding unincorporated corridor regularly, and we’ve learned which county inspectors prioritize fire-separation detail between the junior ADU and main residence, a checkpoint that delays projects when not addressed in the initial drawings.
Serving Ojus, FL - Our Local Coverage Area
We’re based in the Ojus 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 Ojus
Most projects run 8-14 weeks after permit approval, with Miami-Dade County’s plan review adding 4-6 weeks before construction starts. The timeline stretches if structural modifications or electrical service upgrades are needed, which we identify during the feasibility survey so you’re not surprised mid-project. Call (844) 665-0162 for a timeline estimate based on your specific space.
Yes, and it’s a Miami-Dade County permit, not a city permit, because Ojus is unincorporated. The permit covers structural, electrical, plumbing, and HVAC work, and triggers HVHZ compliance for any new exterior openings or envelope modifications. We handle the entire submission and inspection scheduling as part of our scope.
Sometimes, if your target space already has a bathroom nearby and you’re creating a kitchenette rather than a full kitchen. Most Ojus conversions do require at least one plumbing relocation and a new exterior door cut for the separate entrance the county requires. The feasibility survey determines what’s fixed versus flexible in your layout.
The lowest-cost path is converting an existing space with a kitchenette, keeping wet areas near existing plumbing, using stock cabinetry and LVP flooring, and avoiding structural modifications. This typically lands near $45,000-$60,000. Cutting corners on HVHZ-compliant windows or moisture protection costs more later. Call (844) 665-0162 and we’ll show you exactly where to economize without creating problems.
Our workmanship is backed by our standard construction warranty, and materials carry their manufacturer warranties, Cambria’s lifetime residential coverage or KraftMaid’s limited lifetime cabinet warranty. We provide warranty documentation at completion and handle manufacturer claims if issues arise. Specific terms vary by material selection, which we detail in your written estimate.
Homeowners completing a junior ADU & interior conversion often follow up with Kitchen Design & Layout in Ojus for the main residence, or tackle Small & Partial Kitchen Remodels in Ojus to refresh the primary kitchen without matching the full scope of the ADU build.
Get Your Free On-Site Estimate for Junior ADU & Interior Conversion in Ojus
Call (844) 665-0162 to schedule a free feasibility survey. Raymond Estevez or a senior project manager will walk your space, confirm what’s possible under Miami-Dade County’s rules for your specific lot, and deliver a written estimate with real numbers, real material options, and a realistic timeline. No deposit required to get started.
Written by Raymond Estevez, Owner at Groundwork Construction Co., serving Ojus and South Florida homeowners since our founding.