Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Fast, Reliable Home Additions & ADU Across North Bay Village
Home additions and ADU construction in North Bay Village typically run $45,000-$130,000, depending on whether you’re converting a garage, adding a second story, or building a detached unit from scratch. If you live anywhere in the 33141 ZIP, you already know the drill here: everything arrives by bridge, and the salt air never punches out. We’ve spent enough time on these three islands to respect both realities, and we plan every job around them from the first site visit. Call (877) 610-1318 and we’ll come out, walk the property with you, and put real numbers on paper.
North Bay Village sits entirely on artificial fill islands in Biscayne Bay. That’s not a footnote; it’s the first thing any honest contractor has to understand before touching your foundation. When we’re on Harbor Island or Treasure Island, we’re not dealing with Miami mainland soil. We’re dealing with sand and bay fill that hits groundwater a few feet down. A crew that’s never worked here will lose a week figuring that out. We don’t have to.
Why Barrett & Sons Construction Is North Bay Village’s Preferred Home Additions & ADU Company
Tom Barrett founded this company in 1998, and he still answers his own phone. That’s not marketing; it’s how we operate. When a homeowner in North Bay Village calls about a second-story addition on North Treasure Drive or a garage conversion near Kennedy Causeway, Tom is the one who schedules the walkthrough. His sons run the crews, and the crews show up with the Barrett name on their shirts. You’ll see the same faces from permit pull to final inspection.
Local reputation matters more here than in most places. North Bay Village is small, roughly 8,000 people on three islands, and word travels fast. We’ve built our name on written change orders, permits pulled on every eligible job, and the 90-Day Done Right Promise printed on every contract. If something isn’t right after we leave, one call brings Tom back. No phone tree, no out-of-state call center. You call, a live person answers, and we handle it.
We also know what the inspectors in Miami-Dade County look for on island projects. The HVHZ requirements alone trip up out-of-town crews constantly. We don’t have that learning curve. Every Home Additions & ADU project we take in North Bay Village is planned around elevation, wind-load product approvals, and the reality that excavation here often hits bay fill within a few feet of grade. That’s not a problem for us. It’s the baseline.
Our Home Additions & ADU Services in North Bay Village
Most homeowners in North Bay Village are working with a specific set of constraints: limited lot sizes, mid-century concrete block construction, and a building department that treats every island project as a coastal project. We shape our work around those facts. Here’s what we handle most often.
ADU Design & Permitting
Designing an ADU in North Bay Village isn’t a copy-paste job. The site has to account for storm-surge elevation, the HVHZ wind code, and whatever the soil boring tells us about your specific pocket of fill. We pull permits on every eligible project, and we don’t treat the inspector like an obstacle. The permit inspector works for you, not for us, and we’d rather have him sign off on everything than explain later why a wall wasn’t built to code. Allowances, scopes, and change orders all go in writing before work begins.

Garage Conversion ADU
Converting an attached or detached garage is often the smartest dollar-per-square-foot play in North Bay Village, especially in the older concrete block homes that dominate the housing stock. You already have the footprint, the foundation, and the North Bay Village Roofing line. The work becomes about insulation, electrical, egress, and making sure the converted space meets current flood and wind standards. Expect a garage conversion here to run $30,000-$80,000 depending on finishes and whether we’re addressing spalled concrete or corroded rebar along the way.

New Detached ADU
Building a new detached ADU in North Bay Village means running new utilities, digging footings, and often dealing with helical piles or auger-cast foundations because the groundwater is so close to grade. It’s the biggest-ticket option, typically $90,000-$220,000 in this market, but it also adds real rental income or a proper in-law suite. We stage deliveries across the causeway in a tight sequence because there’s no room to park a week’s worth of materials on a small island lot.

Junior ADU & Interior Conversion
Not every addition has to go outward. A junior ADU carved out of an existing floor plan, with its own entrance, kitchenette, and bath, is a practical move for North Bay Village homes where the lot lines leave no room to expand. We’ve done interior conversions that turned unused utility rooms and oversized foyers into rentable living space without a single new footing. That’s the fastest path to added square footage when excavation isn’t an option.

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in North Bay Village
We’re not putting mystery materials off a van into your house. For kitchens and baths inside additions and ADUs, we carry Schluter waterproofing systems and Grohe fixtures regularly. On roofing and exterior assemblies, we trust GAF products that meet HVHZ requirements. We keep our supply chain simple and our brands nameable, because every homeowner in North Bay Village deserves to look up what’s going into their walls. When a specific product has a lead time, we tell you before the contract is signed, not after demo day.
Common Home Additions & ADU Problems We See in North Bay Village Homes
- Bay fill and high groundwater: We routinely hit water within three to five feet of grade on Harbor Island and Treasure Island. Contractors without island experience will pour a footing and pray. We bring in the geotech review early and use helical piles or auger-cast solutions when the site calls for it.
- Spalled concrete and corroded rebar: The mid-century concrete block buildings here have been absorbing salt air for 60-plus years. When we open a wall or chase a crack, we often find reinforcing steel that’s swollen and failing. That has to be addressed before any addition ties into the existing structure.
- HVHZ compliance on tie-ins: Every window, door, and exterior fastening system we touch has to meet Miami-Dade’s High Velocity Hurricane Zone product approvals. That’s not optional, and it changes how we spec materials for additions and ADUs in the 33141 ZIP.
- Staging and access constraints: There’s exactly one practical way on and off these islands, and it crosses a causeway. If a delivery window closes, there’s no alternate route. We sequence materials carefully and keep the site tight, because a blocked driveway on a small island lot shuts down the whole street.
Pricing for Home Additions & ADU in North Bay Village, FL
A whole-home addition in North Bay Village runs $45,000-$130,000. A garage conversion lands between $30,000 and $80,000. A new detached ADU is the high end of the range at $90,000-$220,000, because you’re paying for new foundations, utility runs, and full HVHZ-rated construction from the ground up. Junior ADUs and interior conversions fall below that, often in the $40,000-$90,000 band depending on plumbing rough-ins and finish level. What moves the number isn’t mystery; it’s foundation depth, elevation requirements, and finish choices. We give you a written scope with allowances in writing before any work starts. No surprise invoice at the end, because the allowance that isn’t on paper is a surprise waiting for a date. Call (877) 610-1318 for a free estimate, and we’ll put your number in writing.
We Also Serve Cities Near North Bay Village
We do plenty of work across the causeway too. Kitchen Remodeling in North Bay Village and Bathroom Remodeling in North Bay Village come up on nearly every ADU project we build, and we handle both in-house. You’ll also find our crews in Isle of Normandy, Miami Shores, Bay Harbor Islands, and Surfside, where the same salt-air and flood-elevation realities shape the work.
Serving North Bay Village, FL - Our Local Coverage Area
We’re based in the North Bay Village 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 North Bay Village
We can usually get a site visit scheduled within a few days of your call, and full permitting for an ADU or room addition typically takes several weeks to a few months depending on Miami-Dade review times. The bigger the foundation work, the longer the soil and structural review. Call (877) 610-1318 and we’ll walk you through a realistic timeline for your specific property.
Yes, we cover the entire city, including Harbor Island, Treasure Island, North Bay Island, and every street in the 33141 ZIP. The causeway access doesn’t change our service area; we’re on these islands regularly and we know the parking and staging realities of each one.
A garage conversion in North Bay Village runs $30,000-$80,000, which is consistent with nearby Bay Harbor Islands and Surfside. The price edge here comes down to elevation and foundation conditions; some lots need more site work than a similar project on the mainland. Ask us for a written line-item quote and we’ll show you exactly where the money goes.
We pull permits on every eligible job, no exceptions. North Bay Village sits inside Miami-Dade County’s High Velocity Hurricane Zone, and everything from Windows & Doors - North Bay Village attachments to roof tie-downs has to meet product approval standards. We’d rather have the inspector sign off at every stage than leave you holding a problem later.
Every completed project carries our written 90-Day Done Right Promise. If something isn’t done right, one call brings Tom Barrett back to make it right. That’s on paper, on every contract, no buried fine print. We live twenty minutes away; if something’s wrong, we want to know about it. Call (877) 610-1318 to schedule your free estimate.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving North Bay Village and surrounding South Florida communities since 1998.







Before
After
Before
After
Before
After