Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
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AfterFast, Reliable Home Additions & ADU Across Ojus
Home additions and ADU construction in Ojus run $45,000-$130,000 for a room addition and $90,000-$220,000 for a full detached ADU, and the single biggest variable is whether the materials will pass Miami-Dade County’s High-Velocity Hurricane Zone inspection. We’ve been building in Ojus long enough to know that the county permit queue, the NOA product list, and the salt air all pull on your budget in ways an Aventura contractor never sees. If you’re planning to add a bedroom, build a garage conversion, or put a rental unit in the backyard, call Tom Barrett’s sons at (877) 610-1318 for a free estimate with the coastal-spec materials listed in writing before anyone swings a hammer.
Why Barrett & Sons Construction Is Ojus’s Preferred Home Additions & ADU Company
Tom Barrett founded this company in 1998, and his sons run the crews that show up in Ojus. That matters here because the work is unforgiving: unincorporated Miami-Dade County means every permit goes through the county’s Building Department, every product needs a Miami-Dade NOA number, and every inspection lands on the county’s schedule, not a quick city-hall turnaround. We know which window frames, fasteners, and underlayments pass HVHZ the first time, and which ones get red-tagged. When a 1962 flat-roof CBS home off NE 26th Ave needs a second story, we already know the roof deck likely has zero secondary water barrier and the original tie-downs won’t satisfy current code. That’s not knowledge you get from a franchise call center; it’s knowledge you get from doing the work next door.
Ojus calls are answered by a live person, 24/7. Not a voicemail box, not an out-of-state answering service. And every job we do anywhere in 33160 comes with price changes in writing before the scope moves, permits pulled and inspections signed on every eligible job, and the 90-Day Done Right Promise printed on the contract.
Our Home Additions & ADU Services in Ojus
ADU Design & Permitting
An ADU in Ojus starts with the county, and the paperwork is the first load-bearing wall. Miami-Dade’s Building Department reviews plans through the HVHZ lens, which means the architect’s window schedule, roof assembly, and tie-down details all have to reference NOA-approved products before you get a permit number. We handle the design, the product approvals, the permit submittal, and the inspection scheduling as one package. A detached ADU with a bathroom and kitchenette in Ojus typically lands between $90,000 and $220,000, and the permit and plan check alone can add four to eight weeks to the front end.
Garage Conversion ADU
Converting a garage in Ojus is often the fastest path to rental income, but the original slab, walls, and roof don’t get a pass just because they’re already standing. The county requires the converted space to meet current HVHZ wind-load and water-barrier code, which usually means adding a secondary water barrier at the roof, hurricane straps at the wall-to-roof connection, and impact-rated openings. Budget $30,000-$80,000 depending on whether the garage already has a bathroom rough-in and whether the electrical panel can carry the added load. Most 1950s-1970s Ojus homes need a subpanel upgrade along the way.
New Detached ADU
A new detached ADU on an Ojus lot means starting from the flat limestone up. The county will look at base flood elevation, the NOA list, and the HVHZ wind design before you get a foundation permit, and portions of Ojus sit in FEMA Special Flood Hazard Zones that push slab elevations and flood vents into the design. We spec sealed paver joints on the walkway, hot-dip galvanized hardware throughout, and factory marine-finish windows, because the salt air from the Atlantic doesn’t stop at the Ojus line. Expect $90,000-$220,000 for a finished one-bedroom unit with kitchen and bath.
Junior ADU & Interior Conversion
A junior ADU carved out of existing square footage, like a finished garage bay, a closed-in carport, or a master suite conversion, is the most budget-friendly way to create a legal rental in Ojus. Even a straightforward interior conversion triggers the county’s permit review, and if the original 1960s roof deck hasn’t been retrofitted, the inspector will flag it. Our Home Additions & ADU team handles the interior framing, the wet-wall plumbing, the dedicated entrance, and the retrofit as one written scope of work, so your draw schedule never surprises you.
What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
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You get an upfront price rangeHonest numbers before anyone is dispatched.
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A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Ojus
We install Schluter waterproofing systems in every Ojus ADU bathroom and wet area, because the county inspector recognizes the product line and the warranty holds up under South Florida humidity. For shower fixtures we typically spec Grohe, and for roof assemblies we rely on GAF underlayments and membranes that carry current Miami-Dade NOA approvals. There’s no mystery-brand hardware on our trucks: every product we write into an Ojus contract is one you can look up by name and NOA number before you sign.
Common Home Additions & ADU Problems We See in Ojus Homes
- Non-NOA roofing underlayments failing HVHZ inspection: A cheap underlayment installed on a 1960s flat roof gets red-tagged at rough-in, and the entire roof assembly has to be torn off and redone. That’s a wasted draw schedule and weeks of delay that the low bid never mentioned.
- Salt-air corrosion on inland-spec window frames and railings: Standard aluminum window frames and uncoated railings pit and corrode within two to three years in Ojus, which triggers punch-list failures and corrosion-related leaks around the openings. We spec factory marine finishes and hot-dip galvanized railings from day one.
- Missing secondary water barrier on original flat roofs: Additions that tie into a 1960s built-up tar roof without adding a code-compliant secondary water barrier leak during the first named storm, and the county won’t sign off the permit until the retrofit is done.
- Undersized electrical panels blocking ADU kitchens: Most original Ojus homes have 100-amp panels, and an ADU with a kitchen, mini-split, and laundry pulls too much load. The subpanel upgrade is required by code, but cheap bids leave it out of the contract and then hand you a change order mid-job.
Pricing for Home Additions & ADU in Ojus, FL
Here’s what we see across 33160, written in ranges you can actually budget against.
| Project | Ojus Market Range |
|---|---|
| Home Addition | $45,000-$130,000 |
| ADU Construction | $90,000-$220,000 |
| Garage Conversion | $30,000-$80,000 |
| Impact Window Installation | $8,000-$25,000 |
The coastal-spec upcharge versus an inland materials package runs about 8-15% on most Ojus projects. That covers hot-dip galvanized hardware instead of standard zinc, factory marine-finish window frames instead of raw aluminum, and NOA-approved underlayments instead of off-the-shelf felt. We write every allowance and every scope line in the contract, and every price change arrives as a written change order before the work moves. Call (877) 610-1318 for a free estimate with line items you can actually read.
We Also Serve Cities Near Ojus
Our crews work throughout northeast Miami-Dade, and we regularly serve Home Additions & ADU in Ojus as well as North Miami Beach, Sunny Isles Beach, Aventura, and Hallandale Beach. The county rules change at the Ojus line, but our written pricing and the 90-Day Done Right Promise don’t.
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.
FAQs - Home Additions & ADU in Ojus
Yes, every ADU in unincorporated Ojus must use Miami-Dade County NOA-approved materials regardless of project size, because the building official reviews the entire permit package under the High-Velocity Hurricane Zone standard. Even a small junior ADU conversion gets flagged if the window, roof, or tie-down specs don’t list NOA numbers. Call (877) 610-1318 and we’ll walk you through the product list before you pay for plans.
Because the building code applies to the new work, and Miami-Dade’s HVHZ roof assembly standard requires a secondary water barrier on any roof surface touched by the addition, regardless of what the original 1960s built-up tar roof has. The inspector works for you, not for me, and he won’t sign the rough-in until the barrier is installed. Budget for it in the original contract.
Plan on an additional 8-15% above the inland materials package to cover hot-dip galvanized fasteners, marine-finish aluminum window frames, stainless steel railings, and sealed paver joints throughout the project. The cheap spec fails within two to three years in Ojus salt air, which means you pay for the coastal materials eventually anyway, plus a tear-out. Spend it once.
Yes, the county treats the garage conversion as a change of occupancy, so the converted space must meet current HVHZ wind-load, water-barrier, and impact-opening code even if the rest of the house remains grandfathered. Most Ojus garage conversions also require a secondary water barrier at the roof and hurricane straps at the wall-to-roof connection. We’ll line-item it all in the written scope.
Ojus runs through Miami-Dade County’s centralized Building Department, so plan checks and inspection scheduling take longer, often four to eight weeks on the front end, compared to Aventura or North Miami Beach where the local building office turns things around faster. Your draw schedule should account for the county queue, and we write inspection milestones into the contract so you know when money moves. Call (877) 610-1318 for an exact schedule based on your project.
When Salt Air Decides the Materials: What Ojus Actually Needs
Here’s the thing about building in Ojus that a national estimator will never tell you: the materials that rot first aren’t the big ones. It’s the fasteners, the window frames, the railings, and the paver joints. We just wrapped an enclosed patio and second-story addition on NE 26th Ave, a 1962 CBS flat-roof home where the original built-up tar roof had zero secondary water barrier. The county inspection queue for the permit and rough-in sign-off added two extra weeks, but we replaced every fastener with hot-dip galvanized hardware, specified impact-rated windows with factory marine finish, and used sealed paver joints on the new patio, because the previous owner’s cheap spec had already rotted through the window frames and railings in eight years.
Ojus sits in unincorporated Miami-Dade County, which means one central building department and one product approval list: the Miami-Dade County Notice of Acceptance, written for the High-Velocity Hurricane Zone, the strictest hurricane construction standard in the country. Every material on the job, from the roof underlayment down to the concrete anchor, has to carry an NOA number or it doesn’t get installed. That double gate doesn’t exist in incorporated Aventura, which runs its own building office, or North Miami Beach, which has its own review queue. A contractor who mostly builds across the line won’t have the NOA paperwork reflexes, and that’s where Ojus jobs stall.
Add the salt air, and the spec math gets uglier. Standard aluminum window frames pit within two or three years this close to the coast, uncoated railings turn to chalk, and unsealed paver joints let stormwater wash the bedding out from below. We write hot-dip galvanized or stainless hardware, marine-grade finishes, and sealed joints into every Ojus contract. It’s not an upsell; it’s the only spec that survives.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Ojus, FL.
Call Now for a Free Ojus Estimate
If you’re planning a home addition or ADU in Ojus, call (877) 610-1318. We’ll walk the property, check the existing roof deck and tie-downs, run the permit and product list in writing, and hand you a line-item estimate with the coastal-spec materials already included. No change orders hiding behind an allowance, no mystery brands off a van, and Tom’s name, address, and license number published for you to verify. The 90-Day Done Right Promise is on every contract, in plain words.