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 or building an ADU in Bay Harbor Islands is a different animal than doing it on the mainland, and anyone who tells you otherwise hasn’t pulled a permit here. You’re working on a barrier island ringed by the Intracoastal Waterway, which means Miami-Dade High-Velocity Hurricane Zone compliance, FEMA AE flood elevation rules, and a town building department that knows every block by name. A typical home addition in Bay Harbor Islands runs $45,000-$130,000, and a new detached ADU lands between $90,000 and $220,000. Call (877) 610-1318 and we’ll walk you through what’s realistic for your lot before you spend a dime.
Why Barrett & Sons Construction Is Bay Harbor Islands’s Preferred Home Additions & ADU Company
Tom Barrett started this company in 1998, and his sons run the crews that show up on these islands. That’s not marketing copy. When you call (877) 610-1318, a live person answers, and when the job starts, the name on the truck is the name on the permit. We don’t dispatch strangers from an out-of-state call center. The crew leaders walking your property near the Kane Concourse corridor are the same people who’ll be there if something needs attention 90 days after we finish.
Bay Harbor Islands customers check our license number. They should. Tom publishes his name, his address, and his license number, and we’ll happily point you to the Miami-Dade records before you sign anything. Construction here means dealing with the Town’s own building department, not just the county. We’ve coordinated crane placement and concrete staging on streets where 0.4 square miles of island leaves no shoulder for error. That local working knowledge costs you nothing extra, but it saves you weeks of stop-work orders.
Every scope, every allowance, every price change comes to you as a written change order before work proceeds. The 90-Day Done Right Promise is printed on the contract. And our Home Additions & ADU work in Bay Harbor Islands carries the same guarantee as every other job we do: if it’s not done right, Tom comes back and makes it right, one call.
Our Home Additions & ADU Services in Bay Harbor Islands
ADU Design & Permitting
An ADU on Bay Harbor Islands isn’t a shed with drywall. Because the islands sit inside a FEMA AE flood zone almost without exception, the design phase has to settle elevation questions before framing questions. We handle the full design and permit package through the Town of Bay Harbor Islands’ building department, including HVHZ structural details, floodplain compliance, and the site logistics the town will want to see. You get drawings, engineering, and a permit set in writing, with each allowance itemized.
Garage Conversion ADU
For homeowners in the 33181 zip code with an existing garage, conversion is usually the most cost-effective path to an accessory unit. A garage conversion in Bay Harbor Islands typically runs $30,000-$80,000 depending on whether we’re reinforcing the slab, adding hurricane-impact openings, or running new utilities. The concrete-block garages common on these islands convert well, but they weren’t built under today’s wind codes, so strapping and impact glazing become part of the conversation they didn’t have in 1965.
New Detached ADU
A new detached ADU gives you a clean envelope engineered for the salt air, not patched against it. These projects start around $90,000 and climb with finishes and sitework. On Bay Harbor Islands, sitework is the wildcard: every street is bounded by water on two sides, so compaction, drainage, and elevation have to be handled carefully. We coordinate dumpster and concrete staging with the town’s inspectors before the first forms go up, because a blocked lane on a barrier island stops the whole job, not just your driveway.
Junior ADU & Interior Conversion
A junior ADU, or JADU, converts existing interior space, a den, a media room, a too-big laundry, into a legal dwelling unit with its own entrance where lot lines allow. Homes in Bay Harbor Islands with concrete-block construction lend themselves to this well. The work is less about foundation and more about separation of utilities and egress, both of which the Town reviews closely. Interior conversions here run the full range depending on scope, but we’ll tell you in writing what your specific floor plan can legally accommodate before we ever pick up a hammer.
If your addition scope touches cooking and bathing space, we also handle Kitchen Remodeling in Bay Harbor Islands and Bathroom Remodeling in Bay Harbor Islands under the same contract, same crew, same written change-order discipline.
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. On home additions and ADUs across Bay Harbor Islands, we regularly work with Techo-Bloc and Cambridge Pavers for hardscape and outdoor living areas, and Quikrete products where concrete work is needed. The reason we name brands is simple: if you want to call the manufacturer and ask whether your warranty is real, you should be able to. We keep our suppliers lined up before a job starts so material delays don’t strand a crew on a barrier island with nowhere to stage.
Common Home Additions & ADU Problems We See in Bay Harbor Islands Homes
- Spalling concrete and corroded rebar. Most of the building stock here went up in the 1950s through 1970s, before Miami-Dade’s 1994 HVHZ overhaul, and salt-laden air from the Intracoastal on every side accelerates corrosion. Any structural addition usually begins with concrete restoration before new work can tie in.
- Flood elevation surprises. Because the islands are virtually all FEMA AE zone, the finished floor elevation for living space matters enormously. A contractor who ignores this until the permit review gets a hard stop, and you get a redesign bill. We map the elevation requirements into the estimate on the front end.
- HVHZ-rated openings that were never upgraded. Windows and doors on older Bay Harbor Islands condos and homes don’t meet current windborne-debris standards. When you add a room or build an ADU, the new envelope has to meet today’s code, and the connection to the old envelope needs attention too.
- Staging and access constraints. Roughly 0.4 square miles with access concentrated around Kane Concourse means there’s no oversize staging area. If the dumpster, the concrete truck, and the crane can’t fit, the job doesn’t run. We plan logistics with the Town’s small building department before permits even clear.
Pricing for Home Additions & ADU in Bay Harbor Islands, FL
A full home addition in Bay Harbor Islands typically lands between $45,000 and $130,000. A detached ADU starts near $90,000 and can reach $220,000 with premium finishes and sitework. Garage conversions run $30,000-$80,000. What moves the number here more than style is salt-air structural remediation, flood elevation fill, and HVHZ-rated windows and doors, none of which are optional on this island. When we write your estimate, every allowance is on paper: concrete, roofing, impact glass, finishes. The price won’t move without a written change order, and that’s a promise, not a hope. Call (877) 610-1318 to schedule a free estimate with a line-item scope you can hold us to.
We Also Serve Cities Near Bay Harbor Islands
Beyond Bay Harbor Islands itself, our crews work regularly in Surfside, North Miami, Golden Glades, and Miami Shores. If you’re on the mainland side of the causeway and planning an addition, the permitting authority changes, but our process doesn’t: written scope, written allowances, written change orders, and permits pulled on every eligible job.
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
After your estimate is signed and the permit package is approved by the Town of Bay Harbor Islands, scheduling begins. The town’s review timeline is the biggest variable, not our crew availability. We pull permits and manage the entire submittal for you. Call (877) 610-1318 and we’ll give you a realistic schedule for your specific scope.
Yes. Bay Harbor Islands has its own building department, separate from Miami-Dade County, and they inspect every block. We prepare the drawings, engineering, and permit package, submit to the town, and manage the inspections through final sign-off. The permit inspector works for you, not for us, and that’s exactly how we like it.
Generally yes, and it’s not because of labor markup. Bay Harbor Islands sits in a FEMA AE flood zone almost island-wide, and Miami-Dade HVHZ codes apply to every opening and every roof-to-wall connection. Those compliance costs are real whether the lot is on the west side of the island or the east. A detached ADU here runs roughly $90,000-$220,000. Call (877) 610-1318 for a line-item quote on your lot.
Every job is backed by the 90-Day Done Right Promise, written on the contract. If something isn’t done right, one call brings Tom back to make it right. We also carry the manufacturer warranties on the named materials we install, so if a Techo-Bloc paver fails or a window seal goes, you have a paper trail to the manufacturer.
We work on both, though the structural work on mid-century concrete condos here tends to be concrete restoration and impact-glazing retrofits rather than additions. For single-family lots and low-density properties in the 33181 zip code, additions and ADUs are more common. Tell us what you have and we’ll tell you what’s possible. Estimates are free.
Get Your Bay Harbor Islands Addition Started Right
You’ve probably been burned before, and that’s precisely why we write everything down. Scope in writing, allowances in writing, change orders in writing. Tom Barrett lives close enough to Bay Harbor Islands that if something’s wrong, he’ll hear about it at the store before you have to call twice. We’re the Home Additions & ADU team that puts the price on paper before a single nail moves. Call (877) 610-1318 today to schedule your free estimate, or ask for a free second opinion on any written estimate you already have.
Written by Tom Barrett, Owner at Barrett & Sons Construction, with crews serving Bay Harbor Islands and the surrounding communities since 1998.