Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Fast, Reliable Home Additions & ADU Across Coconut Grove
Home additions and ADU construction in Coconut Grove typically run $45,000-$130,000 for a room addition and $90,000-$220,000 for a new detached ADU, with garage conversions landing between $30,000-$80,000. The number that most homeowners in the 33114 don’t see coming is the permit sequence: in this neighborhood, a standard addition can require both HEP Board historic review and an Urban Forest Ordinance arborist report on the same permit set. That’s the part that stalls projects, and it’s why we start every Coconut Grove estimate by walking the lot, not just the floor plan. Call Barrett & Sons at (877) 610-1318 and we’ll tell you what your specific street will actually require.
We’re an owner-operated company founded in 1998, and Tom Barrett and his sons are on-site most days in Coconut Grove. Our Home Additions & ADU team knows the difference between a lot off Main Highway with a protected banyan in the right-of-way and a mid-century CBS house on a standard 40-foot platted lot near the bay. That difference changes your foundation design, your staging plan, and your final price, and we put it on paper before you sign anything.
Why Barrett & Sons Construction Is Coconut Grove’s Preferred Home Additions & ADU Company
Coconut Grove is not a neighborhood where you hand a permit set to a crew that’s never worked here. The housing stock ranges from early-1900s Old Florida vernacular cottages to 1920s Mediterranean Revival homes and mid-century concrete block structures, and many carry local historic landmark designations. An addition on one of those properties that skips HEP Board review doesn’t just delay the job; it triggers a stop-work order and permit revocation. We pull the historic review before we pour anything, because we’ve watched other crews learn that lesson the hard way.
We’ve worked on tight lots throughout the Grove, from the cottage blocks near the Peacock Park area down toward the bay side where FEMA flood zones reshape ground-floor plans. On a recent conversion off SW 27th Avenue, our crew turned a 1930s Mediterranean Revival two-car garage into a 600-square-foot ADU. The existing slab-on-grade had cracked from a protected strangler fig’s root running 50 feet from the trunk, so we redesigned to pier-and-beam with an arborist-approved root barrier, added a party-wall notice for the shared side wall with the neighbor’s CBS cottage, and sequenced our dumpster and concrete pump from the street with a parking waiver. Final inspection sign-off came 11 weeks after rough-in. That’s the kind of job you only finish clean if you’ve done it in this neighborhood before.
Every Coconut Grove job comes with the same written terms: permits pulled and inspections signed, every price change as a written change order before work moves, and the 90-Day Done Right Promise on every contract. One call brings Tom back if something isn’t right. Call (877) 610-1318 and a live person answers, day or night.
Our Home Additions & ADU Services in Coconut Grove
ADU Design & Permitting
An ADU in Coconut Grove starts with the permit set, not the floor plan. We handle the HEP Board submittal when your property is locally designated, the arborist report when protected tree root zones touch your building envelope, and the Miami-Dade flood elevation review when your lot sits below Base Flood Elevation. Our design work produces a set that a Miami-Dade tree inspector can sign off without stopping your pour. That’s the difference between an 11-week garage conversion and a six-month stall.

Garage Conversion ADU
A garage conversion in Coconut Grove typically runs $30,000-$80,000, and the price swings on what’s under the slab and what’s beside it. Many of the older garages in the Grove were built slab-on-grade decades before the current Urban Forest Ordinance, and root systems from protected banyans and live oaks have since cracked the concrete. We pull an arborist report before we submit drawings, because Miami-Dade’s tree inspector can halt a job mid-pour if root encroachment wasn’t addressed in the approved plans. That one report often changes the foundation design from slab to pier-and-beam, and we write that cost into the estimate up front, not as a surprise after demo.

New Detached ADU
A new detached ADU in Coconut Grove runs $90,000-$220,000, and the lot itself does a lot of the cost-causing. The neighborhood’s protected canopy of banyan, live oak, and strangler fig trees has root zones that extend 40-60 feet from the trunk, and on a tight cottage lot that often means your ADU footprint has to shift or your foundation has to change. We’ve designed ADUs on 40-foot-wide lots where the only workable solution was pier-and-beam with root barriers, and we’ve done it without crushing the neighbor’s property line or blocking the street with materials. Access affects the quote, so we walk the site before we write the number.

Junior ADU & Interior Conversion
A junior ADU, usually an interior conversion of an existing attached space, is often the fastest path to rental income in Coconut Grove because it doesn’t trigger the same site disturbance a detached structure does. But interior conversion doesn’t mean interior-only review: if you’re in a locally designated early-1900s cottage, any exterior modification, including a new entrance or window for the JADU, requires HEP Board approval. We handle that submittal and coordinate it with the building permit so you’re not waiting on two separate review queues with two different start dates.

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 Coconut Grove
We install and service premium brands across every trade, and on Coconut Grove additions and ADUs we often specify impact-rated window and door lines from Simonton, PGT, and CGI. In flood zones and wind-borne debris regions along Biscayne Bay, impact-rated openings are a code requirement on much of the 33114 housing stock, and naming the brand on the estimate protects you from getting mystery materials off a van. We stock common parts and hardware for these lines, which keeps a mid-project change order from turning into a two-week wait.
Common Home Additions & ADU Problems We See in Coconut Grove Homes
- Footings poured before the arborist report. A Miami-Dade tree inspector can halt a pour and force demolition of concrete within protected root zones. We’ve seen it happen on a second-story addition where the roots were 45 feet from the trunk. The report costs a few hundred dollars; the demolition costs thousands.
- HEP Board review missed on an exterior modification. If your early-1900s cottage carries a local landmark designation, adding a dormer, a new entrance, or even changing window openings without HEP Board approval triggers a stop-work order. We file that review with the building permit, not after the fact.
- Staging and parking underestimated on narrow streets. A dumpster or material laydown on the narrow 33114 right-of-way without a Miami parking waiver gets tow-in-the-middle-of-pour citations. We sequence deliveries and pull parking waivers before the first truck arrives.
- Flood zone elevation surprises. A significant portion of Coconut Grove sits in FEMA Special Flood Hazard Zones, and Miami-Dade’s Base Flood Elevation requirements have gotten more aggressive in recent years. A ground-floor addition that wasn’t designed above BFE can mean raising the entire structure at real cost.
Pricing for Home Additions & ADU in Coconut Grove, FL
Coconut Grove pricing runs higher than suburban Miami-Dade, and there’s a reason: the permit sequence here is genuinely more complex. Here’s where the money goes on most Grove projects:
| Project Type | Coconut Grove Price Range |
|---|---|
| ADU Construction | $90,000-$220,000 |
| Garage Conversion | $30,000-$80,000 |
| Home Addition | $45,000-$130,000 |
What moves the number: historic designation status, flood zone elevation, arborist findings, access for equipment, and whether your job needs party-wall notices for a shared wall. We write every allowance and every change order in writing before work happens. No surprise invoices at the end, because a price that isn’t on paper is a surprise waiting for a date. Call (877) 610-1318 for a free estimate that reflects your actual lot, not a generic square-footage formula.
We Also Serve Cities Near Coconut Grove
We work throughout Coconut Grove and the surrounding South Miami-Dade communities, including Coral Gables, Glenvar Heights, South Miami, and Coral Terrace. If you’re a few blocks outside the Grove proper, call us anyway: the permit rules, flood zones, and tree ordinances shift street by street down here, and we’ll tell you straight what your address triggers. The phone number is the same: (877) 610-1318.
Serving Coconut Grove, FL - Our Local Coverage Area
We’re based in the Coconut Grove 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 Coconut Grove
Possibly yes, because the two reviews run on separate tracks. If your house is not locally designated, HEP Board review may still apply if your lot sits within a historic district overlay, or if the addition changes a street-facing elevation that the HEP Board reviews under conservation guidelines. Separately, any construction within the root zone of a protected banyan, live oak, or strangler fig triggers Urban Forest Ordinance review, regardless of your home’s historic status. The only way to know for your specific address is a permit review walk, which we do as part of every Coconut Grove estimate. Call (877) 610-1318 and we’ll check both tracks before you spend a dollar on drawings.
We issue a formal party-wall notice to the adjacent owner before any work touches the shared wall, and we document the existing condition with photos and a written report. In older cottage blocks where homes were built close enough to share a wall or sit two feet off the property line, we also sequence demolition and framing carefully so vibration doesn’t crack the neighbor’s plaster. The notice isn’t a courtesy; it’s protection for both owners and it keeps a dispute from becoming a stop-work order mid-framing.
If your lot is in a FEMA Special Flood Hazard Zone, your ground-floor addition must meet Miami-Dade’s current Base Flood Elevation requirements, which often means raising finished floor above the BFE listed for your 33114 address. Depending on how much your existing structure already complies, this can add tens of thousands to the foundation scope. We pull an elevation certificate and review the flood map for your specific property before we write the estimate, so that cost shows up in the first number you see, not the last.
We pull a Miami parking waiver before we occupy any street space, and we sequence material deliveries so a truck shows up, drops, and leaves. On a tight lot where there’s no side yard for a dumpster, we coordinate with the City of Miami right-of-way office so the dumpster sits legally at the curb for the days we need it, then gets pulled. We’ve never had a crew cite a parking violation during a pour, and we intend to keep it that way. Access affects your quote, so we walk the street before we write the number.
Because the root systems of Coconut Grove’s protected banyans and live oaks can extend 40-60 feet from the trunk, well past the visual footprint of the tree. A second story adds weight and often changes drainage and foundation loads, and if the new footers or the new roofline encroach on a protected root zone, Miami-Dade’s tree inspector can stop the pour. An arborist report tells us where roots actually are, so we can design the foundation correctly the first time, whether that means piers, root barriers, or a shifted footprint. It’s a small line item that prevents a very expensive mid-project redesign. Call (877) 610-1318 and we’ll explain what your lot’s trees actually require.
Schedule Your Coconut Grove Home Addition or ADU Estimate
If you’re planning an addition or ADU in Coconut Grove, the first step is a walk of your actual lot. We’ll check the historic designation status, the flood zone, the tree canopy, the access, and the neighbor’s wall, then put a written estimate in front of you with every permit fee, every allowance, and every change order spelled out. No vague numbers, no mystery brands, no surprises at the end. Call Barrett & Sons Construction at (877) 610-1318 for your free estimate, and ask for Tom or one of his sons. A live person answers the phone every time.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Coconut Grove since the company’s founding in 1998.







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