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 Flagami
A full home addition or detached ADU in Flagami typically costs between $45,000 and $130,000 when it’s done to Miami-Dade code, with a new detached ADU running $90,000 to $220,000. The number moves with square footage, rock excavation, and how much legacy unpermitted work has to be reconciled before the new framing starts. We’ve been working on Flagami’s CBS homes long enough to know what the permit office is going to ask before you even file.
If you’re planning an addition in the 33144 zip and want a straight answer on what it’ll actually cost, call Tom Barrett’s team at (877) 610-1318. We’ll walk the property, check what’s already there against what the county says should be there, and give you a written scope with real numbers.
Why Barrett & Sons Construction Is Flagami’s Preferred Home Additions & ADU Company
We’re not a franchise sending a salesman with a laptop and a financing pitch. Tom Barrett founded this company in 1998, and his sons run the crews. When we take on a Home Additions & ADU job in Flagami, the person who signs the contract is the same person you’ll see at the permit counter and on the job site.
Flagami homeowners tend to ask the same two questions before they sign anything: will you pull permits, and will the price change at the end? Our answer is the same every time. Permits get pulled on every eligible job, inspections get signed, and every change in scope arrives as a written change order before work proceeds. No surprise invoices. The allowance that isn’t on paper is a surprise waiting for a date, and we don’t work that way.
We’re familiar with what the Miami-Dade building department requires on Flagami properties, particularly when older CBS homes have picked up unpermitted enclosures over the decades. That local knowledge is the difference between an estimate that survives contact with the permit office and one that falls apart in week two.
Our Home Additions & ADU Services in Flagami
We handle the full range of additions and accessory dwelling units, but four services come up most often in Flagami. Here’s what each one actually involves on the ground here.
ADU Design & Permitting
This is where Flagami jobs live or die. Before we draw a single wall, we audit the existing structure against county records. Homes in the 33144 zip carry decades of enclosed carports, converted screen rooms, and secondary structures that were never permitted. Those have to be reconciled before the new ADU permit moves forward. We handle the design, the Miami-Dade NOA product selections, the structural calcs for 175-mph wind loads, and the full permit package. You get a documented path from existing conditions to final inspection.
Garage Conversion ADU
Converting an attached garage into a rental unit or in-law suite is one of the smartest moves in Flagami, given the density of single-story CBS homes and the demand for secondary units. But most garages here have issues hiding in plain sight: old flat built-up roofs that don’t meet post-Andrew uplift requirements, missing tie-downs, slab plumbing that’s rusted through. We convert the space, fix the envelope, and bring the whole assembly up to current Miami-Dade code so the finished ADU is insurable and legal.
New Detached ADU
Building a new detached ADU in Flagami means starting from scratch with the right foundation. We hit oolitic limestone in most excavation, usually six to twelve inches down, so our estimates include rock excavation from day one. The structure gets engineered for 175-mph wind design, which dictates anchor bolts, strapping, and shear wall connections. We use Miami-Dade NOA-rated windows and doors, and every inspection is documented for your wind mitigation file.
Junior ADU & Interior Conversion
A junior ADU or interior conversion takes existing square footage and turns it into a permitted second unit. In Flagami that often means converting an oversized laundry room, a formal dining room nobody uses, or the back half of a ranch into a studio with its own entrance, kitchenette, and bath. The plumbing is usually the wild card, since many of these older homes still have cast-iron drain lines in the slab. We scope that during the estimate, not after the saws start.
Second Story Additions
Adding a second story in Flagami is a serious structural conversation, not just a framing project. The first-floor walls, footings, and slab all carry load in ways the original 1950s builder never anticipated. We evaluate whether the existing CBS walls can take the new load or need reinforcement, and we design the vertical addition to meet Miami-Dade’s 175-mph wind standard from the roof down to the anchor bolts. Rock excavation for new footings is priced up front.
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 Flagami
When we install windows, doors, and glazing on a Flagami addition, we’re working with manufacturers whose products carry Miami-Dade County Notice of Acceptance approval: Simonton, PGT, and CGI. That NOA mark matters here. A window that’s approved for the state of Florida but doesn’t carry Miami-Dade NOA won’t pass inspection in the 33144 zip, and it won’t help your wind mitigation report when the insurer asks. We stock the local product lines our Flagami jobs need, which keeps lead times shorter than waiting on a shipment nobody ordered.
Common Home Additions & ADU Problems We See in Flagami Homes
- Unpermitted legacy work blocks the new permit. A 1950s CBS home may have had a carport enclosed in the 1980s or a screen room converted without a permit. When you pull a permit for a new addition, the county wants to know what that existing square footage is doing. We reconcile it as part of the scope, so your addition permit doesn’t stall.
- Oolitic limestone turns every footing into a jackhammer job. Flagami sits on the Miami Rock Ridge, and the limestone is typically six to twelve inches below the surface. Contractors who quote flagstone-level digging get a rude awakening. We price rock excavation in the initial estimate.
- Flat built-up roofs from the pre-Andrew era fail current uplift requirements. Most of Flagami’s housing stock predates the 1992 hurricane. A room addition tied into an old flat roof inherits that roof’s problems. We scope the roof integration so the whole assembly meets current code, not just the new part.
- Cast-iron and galvanized plumbing in the slab gives out mid-project. We’ve opened walls and found drain lines that are more rust than pipe. When you’re adding a bath or kitchenette, that old plumbing has to be addressed. It’s in our scope from the start, not a surprise line item at the end.
Pricing for Home Additions & ADU in Flagami, FL
Here’s where Flagami pricing gets real. A full permitted home addition with NOA-rated structural connections, impact openings, rock excavation, and the pre-permit compliance audit runs $45,000 to $130,000. A new detached ADU with Miami-Dade NOA products, site prep, utilities, and a hurricane-rated envelope lands between $90,000 and $220,000. A garage conversion, including reconciliation of legacy unpermitted work and NOA window and door replacement, runs $30,000 to $80,000.
| Project Type | Typical Range in Flagami |
|---|---|
| Home Addition (permitted, NOA-rated, rock excavation) | $45,000 - $130,000 |
| ADU Construction (new detached, hurricane-rated envelope) | $90,000 - $220,000 |
| Garage Conversion ADU (with legacy work reconciliation) | $30,000 - $80,000 |
What moves the number? Square footage, second-story engineering if you’re going up, how much rock the footings have to chew through, and how much unpermitted work the county wants regularized before your new permit clears. We give you a written line-item estimate so you can see exactly where every dollar goes. Call (877) 610-1318 and we’ll schedule a walkthrough. Estimates are free.
We Also Serve Cities Near Flagami
Our crews work throughout the area around Flagami, so if you’re in West Miami, Westchester, Coral Terrace, or Fountainebleau, the same team, same permitting discipline, and same written-scope approach applies. Wherever you are, the estimate is free and the price changes only when you sign a written change order.
Serving Flagami, FL - Our Local Coverage Area
We’re based in the Flagami 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 Flagami
Because Flagami sits in Miami-Dade County, which operates under the High Velocity Hurricane Zone provisions of the Florida Building Code. Since 2002, every new or altered building in the county must be designed for wind speeds up to 175 mph, the strictest county-level standard in the continental U.S. A product with only Florida statewide approval has not been tested and certified to Miami-Dade’s stricter wind-load, water-infiltration, and impact standards. If a contractor installs non-NOA windows, roof cladding, or tie-downs on your Flagami addition, the inspection will fail and you’ll have to tear it out and redo it. The NOA mark is the product’s proof that it meets the county-specific requirement. Call (877) 610-1318 if you want us to look at what your project needs before you buy anything.
Yes, but the unpermitted enclosure has to be reconciled as part of the same permit package before the county will sign off on the new ADU. We pull the property’s permit history, compare it to what’s physically on the ground, and document the legacy work. Then we file the appropriate permits to bring the existing enclosed space into compliance while the garage conversion proceeds. A contractor who skips this step leaves you exposed to code enforcement action and insurance denial later. We handle the audit as part of our scope. Call (877) 610-1318 and we’ll walk the property and tell you exactly what the county needs to see.
Footing depth depends on the engineer’s design and the county’s structural requirements, but the bigger cost driver in Flagami is what’s under the footing. The Miami Rock Ridge limestone is typically six to twelve inches below grade here, which means every footing trench, every plumbing trench, every post hole becomes a jackhammer excavation. We price rock excavation into our initial estimate. A crew that quotes you Broward County digging prices will hit limestone on day one and hand you a change order by day three. Our price includes the rock work from the first written scope, so there’s no surprise. Call (877) 610-1318 for a walked estimate with the excavation spelled out in writing.
Yes, it can, but only if the work is documented the right way. When we finish a second-story addition in Flagami, the final inspection sign-off includes verification of the structural connections, the Miami-Dade NOA-rated tie-downs, and the impact openings. That paperwork goes into your wind mitigation file. When your insurer reviews the policy, a properly documented, post-1992-code second story with rated connections can qualify for wind mitigation credits that reduce the wind portion of your premium. Unpermitted work gets you none of that, and it can trigger a non-renewal if the insurer finds out. We’ve seen it happen. If you’re planning a second story, call (877) 610-1318 and we’ll explain what documentation you’ll have after the final inspection.
Sometimes yes, sometimes no, and it depends on what the engineer finds in the existing walls, footings, and slab. CBS homes from the late 1940s through early 1970s were built with concrete block walls and slab-on-grade foundations that may or may not have the load capacity for a second story. We do a structural evaluation before we draw framing plans. If the walls need reinforcement, we design for that. If the footings need to be widened or deepened, we include the rock excavation in the written scope. The point is, we answer this with an engineer’s stamp and a county-approved plan, not a guess. Call (877) 610-1318 and we’ll set up the structural review.
Planning a home addition or ADU in Flagami means working with a contractor who understands Miami-Dade’s 175-mph wind code, the NOA product approval system, the rock under every footing trench, and the permit history hidden in every 1950s CBS home. Tom Barrett and his sons have been doing exactly that since 1998. Every price change arrives in writing before work proceeds. Every eligible job gets permits pulled and inspections signed. And every completed job is backed by our 90-Day Done Right Promise. Call (877) 610-1318 to schedule your free estimate.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Flagami and surrounding communities since 1998.