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 Bay Harbor Islands
Adding square footage on one of two small barrier islands in Biscayne Bay isn’t like building on the mainland. The Town of Bay Harbor Islands enforces its own permit process, FEMA flood-elevation rules touch nearly every lot, and Miami-Dade HVHZ wind codes shape every connection from roof to slab. We’ve been building here long enough to know which questions the town’s inspectors will ask before they ask them. If you’re planning a Home Additions & ADU project in the 33181 zip code, call Barrett & Sons Construction directly at (877) 610-1318 and talk to a live person, not a voicemail box.
Why Barrett & Sons Construction Is Bay Harbor Islands’s Preferred Home Additions & ADU Company
The permit inspector works for you, not for me. That’s how Tom Barrett has run Bay Harbor Islands projects since 1998, and it’s why our crews show up knowing the town doesn’t want surprises any more than you do. We coordinate crane placement, concrete staging, and dumpster positioning with the Town of Bay Harbor Islands building department before a single form gets poured, because on an island of roughly 0.4 square miles, there’s no room for guesswork.
We’re owner-operated. Tom’s sons run the crews, and background-checked, uniformed team members carry the Barrett & Sons name on every visit. When a homeowner on Kane Concourse calls with a question, the answer comes from someone who will see them at the grocery store, not a call center three states away. That’s the L.O.C.A.L. code we work by: Local roots, On time, Community first, Accountable, Loyal.
Every contract carries our 90-Day Done Right Promise in writing. If something isn’t right, one call brings Tom back. That promise applies to ADU design, garage conversions, second-story additions, and every other project we take on in Bay Harbor Islands.
Our Home Additions & ADU Services in Bay Harbor Islands
ADU Design & Permitting
A new ADU on Bay Harbor Islands starts with two sets of rules: the Town of Bay Harbor Islands municipal code and Miami-Dade County HVHZ standards. We handle both. Typical design and permitting for an accessory dwelling unit here runs $90,000 to $220,000 all-in, and the paperwork takes as long as it takes; we don’t cut corners to make a date. Your allowances show up on paper before your funds show up in someone else’s account.
Garage Conversion ADU
Many 1950s and 1960s homes on the islands have garage footprints that can become rentable or family-use living space. Garage conversions in Bay Harbor Islands typically range from $30,000 to $80,000, with the tricky parts being flood-zone elevation requirements and bringing the existing slab up to current code before framing begins. We pull the permits, schedule the inspections, and hand you a sign-off, not a list of things to finish yourself.
New Detached ADU
Building a detached ADU on a small island lot means every inch of setback counts. A new detached ADU in Bay Harbor Islands runs $90,000 to $220,000 depending on size, finish level, and how much site work your lot needs. Salt air exposure from the Intracoastal on all sides means we spec stainless or coated fasteners, marine-grade strapping, and impact-rated openings from day one, not as an upgrade conversation later.
Junior ADU & Interior Conversion
For homeowners who don’t need a full separate structure, a junior ADU or interior conversion can add a bedroom, bath, and kitchenette within the existing envelope. These projects typically start around $45,000 in Bay Harbor Islands and climb with finish choices. Converting a den, oversized laundry room, or enclosed patio often costs less than a ground-up build because the roof and walls are already there, though the permit and flood-zone review still apply.
What happens when you call
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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 Bay Harbor Islands
We install materials you can look up, not mystery brands off a van. For exterior flatwork and paver areas around new ADUs on Bay Harbor Islands, we regularly use Techo-Bloc and Cambridge Pavers, both of which hold up better than cheaper alternatives in constant salt-air exposure. We stock common components locally so our crews aren’t waiting on shipments from out of state when a project is mid-stream, and that matters when you’re scheduling around hurricane season, not just a calendar.
Common Home Additions & ADU Problems We See in Bay Harbor Islands Homes
- Spalling concrete and corroded rebar in existing slabs. Decades of salt-laden marine air from the Intracoastal on all sides means older concrete carries hidden corrosion. Any addition tied into a 1950s-1970s slab needs a structural assessment first.
- Flood-zone elevation conflicts with existing floor heights. Nearly all of Bay Harbor Islands sits in a FEMA AE zone. Raising an addition to meet elevation requirements can create awkward transitions from old floor to new, and we solve that at the design stage, not with a ramp bolted on after inspection.
- HVHZ wind-load strapping missing from original construction. Pre-1994 buildings often lack the roof-to-wall connection hardware Miami-Dade now requires. When we tie an addition into an older house, we bring the connections up to current code across the entire affected area.
- Logistics on 0.4 square miles. Kane Concourse is the main artery, and every street is tight. Crane placement, concrete-truck staging, and dumpster positioning must be coordinated with the Town of Bay Harbor Islands separately from Miami-Dade County, and we’ve learned which blocks allow what before the inspector shows up.
Pricing for Home Additions & ADU in Bay Harbor Islands, FL
A full home addition in Bay Harbor Islands typically runs $45,000 to $130,000. An ADU build runs higher, $90,000 to $220,000, because of the separate foundation, utility runs, and permit work involved. Garage conversions sit in the middle at $30,000 to $80,000. What moves the number? Finish level, site access, structural remediation on the existing building, and how much elevation work your flood zone requires. You’ll get a written line-item estimate before any contract is signed, and every change arrives as a written change order before work proceeds. Call (877) 610-1318 for your free estimate. No trip charge inside the county, and a permanent 10% Senior & Veteran discount applies to all our work.
We Also Serve Cities Near Bay Harbor Islands
Our crews work up and down the barrier islands and into the mainland communities around Biscayne Bay. If you’re in Surfside, North Miami, Golden Glades, or Miami Shores, we handle Kitchen Remodeling in Bay Harbor Islands and Bathroom Remodeling in Bay Harbor Islands with the same written-change-order discipline and the same 90-Day Done Right Promise. Same crew, same standards, same phone number.
Serving Bay Harbor Islands, FL - Our Local Coverage Area
We’re based in the Bay Harbor Islands 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 Bay Harbor Islands
Permit review with the Town of Bay Harbor Islands typically takes longer than the mainland because the town runs its own building department separate from Miami-Dade County, and FEMA flood-zone review adds a step on nearly every lot. We’re usually on-site within a few weeks of permit issuance. Call (877) 610-1318 and we’ll give you a real timeline for your specific address, not a sales answer.
Yes, we cover all of Bay Harbor Islands, including the 33181 zip code and every street off Kane Concourse. The two islands are small enough that our crews can be on any block quickly, and we coordinate staging and dumpster placement according to the town’s own logistics rules, which differ from Miami-Dade County’s.
If we open a wall or slab and find spalled concrete, corroded rebar, or missing hurricane strapping, we document it, write a change order, and get your signature before we proceed. You will never get a surprise invoice at the end. The permit inspector sees the same thing we do, and we’d rather fix it right than argue about it later.
Bay Harbor Islands tends to run at the higher end of Miami-Dade pricing because elevation requirements apply to nearly every lot, HVHZ wind codes are strict, and the town’s separate permit process adds review time. A detached ADU here typically runs $90,000 to $220,000, compared to slightly lower numbers on the mainland where flood-zone rules don’t blanket the map. Exact pricing depends on your lot and scope; call (877) 610-1318 for a written estimate.
Every job carries our written 90-Day Done Right Promise. If it’s not done right, Tom comes back and makes it right, one call. That promise sits on the contract, not in fine print, and it applies to structural work, finishes, and everything in between. We also pull permits and schedule inspections on every eligible job, because the inspector’s sign-off is part of the delivery.
Call Barrett & Sons Construction at (877) 610-1318 for a free estimate on your home addition or ADU in Bay Harbor Islands. Tom or one of his sons will answer, and you’ll get numbers on paper before any work begins.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Bay Harbor Islands since 1998.