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 Coral Gables
A typical home addition in Coral Gables runs $45,000-$130,000, while a new detached ADU runs $90,000-$220,000. Most projects take six to fourteen months from signed contract to final inspection, but the real driver is not labor; it’s the Board of Architects’ design-review timeline and the long-lead materials that must clear it. Call (786) 321-4970 to schedule your free estimate.
We serve Coral Gables from our Miami office, with crews that know the difference between a standard Miami-Dade permit and the separate architectural-review layer that governs every exterior project here. Our Home Additions & ADU team has worked on homes from the Village of Merrick Park to the Granada neighborhood, and we build the Board of Architects’ four-to-eight-week review buffer into every written timeline before a customer signs. That is the difference between a quote that holds and one that doesn’t.
Why Rowan Construction Group Miami Is Coral Gables’s Preferred Home Additions & ADU Company
We have delivered more than 4,000 projects since 2007, every one with a written price before work started and a documented photo record when the crew left. In Coral Gables, that discipline matters more than in most cities because the Board of Architects can restart a timeline, but it cannot restart a budget that was never fixed in writing.
Our crews are background-checked and uniformed; a live person answers calls 24/7. We pull permits, pass inspections, and include the photo documentation as standard, not an upgrade. Grant Rowan, our founder, built this company on the Haven Standard - Clause 1 is the written price before any work starts, and no change proceeds without a signed change order. That is how our projects finish within a few percent of the number the customer agreed to.
We also offer a Free Second Opinion on any written estimate from another contractor. Bring us a competitor’s quote and we will review it line by line at no charge.
Our Home Additions & ADU Services in Coral Gables
ADU Design & Permitting
Every ADU in Coral Gables must clear two gates: the Board of Architects’ Mediterranean Revival design review, then Miami-Dade permitting. We handle both, and we never pull a permit or order tile until the Board signs off. On a recent project near the Granada neighborhood, the Board rejected a code-compliant barrel tile because its curvature did not match the century-old originals on the adjacent contributing property. We had to source reclaimed tile and restart the four-to-eight-week clock. Because the scope, allowances, and change-order discipline were already in writing, the budget stayed fixed while the calendar moved.
New Detached ADU
A new detached ADU in Coral Gables runs $90,000-$220,000. These are the most complex projects we build here because they trigger every local layer: Board of Architects review, HVHZ wind-uplight and impact-resistance standards, and often shallow-aquifer dewatering when excavation hits standing groundwater within two to four feet. We build all of this into the written price before ordering a single long-lead item. The calendar is set by custom millwork, architectural glass, and specialty finishes - not by how fast our crew can frame.
Garage Conversion ADU
A garage conversion ADU in Coral Gables runs $30,000-$80,000. These projects are faster than detached units because they typically avoid new foundation work, but they still require Board of Architects approval for any exterior modification - window openings, stucco profiles, roofline changes. We coordinate with the customer’s architect or designer to ensure the submittal matches the mandated aesthetic before we submit, not after.
Junior ADU & Interior Conversion
Junior ADUs and interior conversions are the one category that sometimes bypasses the Board of Architects, provided no exterior changes are made. We verify this at the first site visit. If the project stays interior-only, we can often move straight to Miami-Dade permitting and compress the timeline significantly. The written price still comes first, and the photo record still documents every visit.
Second Story Additions
A second story addition in Coral Gables runs $45,000-$130,000. These projects demand HVHZ structural engineering and often require matching existing coral rock or stucco detailing that the Board will scrutinize against adjacent contributing properties. We bring in stonework specialists when needed - standard modern masonry methods will not anchor into porous Miami oolitic limestone - and we source materials with lead times that account for the review buffer.
Room Additions & Sunrooms
Room additions and enclosed patios follow the same Coral Gables rules: Board of Architects first, permits second, materials ordered only after approval. We have learned to specify period-compatible profiles and color palettes from the initial design meeting so the submittal does not cycle back.
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.
BeforeAfterTrusted Brands We Service in Coral Gables
We source across fifty-plus vetted brands so our written quotes carry honest numbers, not inflated allowances. For ADU and addition plumbing fixtures, we regularly specify Toto and Delta for their HVHZ-rated and water-efficient lines; for bathroom and kitchen fittings in high-end Coral Gables work, we use Schluter waterproofing membranes and American Standard fixtures where the architect’s spec calls for them. We do not list brands to impress. We name them because the customer can cross-reference the model number, check the lead time, and verify that the allowance in our written quote matches the distributor’s current price.
Common Home Additions & ADU Problems We See in Coral Gables Homes
- Permits pulled before Board of Architects approval. Contractors unfamiliar with Coral Gables treat it like Miami or South Miami, order standard barrel tile, and discover the Board will reject it for curvature mismatch. The fix is custom or reclaimed tile and a four-to-eight-week restart. We build the buffer in from day one.
- Excavation with no dewatering plan. Coral Gables sits atop a shallow limestone aquifer. We regularly see ADU slab excavations hit standing groundwater at two to four feet. Our scopes include dewatering and special foundation approaches as a line item, not a surprise.
- Standard masonry anchors into coral rock. The 1920s-1950s walls in neighborhoods like Granada and near the Village of Merrick Park are built from Miami oolitic limestone - porous, structurally irregular, and unforgiving of modern fasteners. We bring in historic South Florida stonework specialists when the substrate demands it.
- HVHZ compliance treated as an afterthought. Every structural modification in Coral Gables must meet Miami-Dade’s High-Velocity Hurricane Zone standards, the strictest in the country. We engineer for wind uplift and impact resistance from the first drawing, not the first inspection failure.
Pricing for Home Additions & ADU in Coral Gables, FL
These are the ranges we put in writing before any work starts. They reflect Coral Gables’s specific conditions: Board of Architects review timelines, HVHZ engineering requirements, shallow-aquifer foundation work, and the custom or reclaimed materials that the mandated Mediterranean Revival aesthetic often requires.
| Project Type | Price Range in Coral Gables |
|---|---|
| New Detached ADU | $90,000-$220,000 |
| Garage Conversion ADU | $30,000-$80,000 |
| Home Addition | $45,000-$130,000 |
| Second Story Addition | $45,000-$130,000 |
What moves a project within these ranges: square footage, structural complexity, foundation conditions (especially dewatering needs), and the grade of finishes. A Toto fixture allowance differs from a stock alternative. Custom millwork and architectural glass carry lead times that extend the calendar but do not change the written price once the scope is signed. Under Clause 1 of the Haven Standard, the price is fixed before anyone starts. No change proceeds without a signed change order. That is how we have kept 4,000-plus projects within a few percent of the agreed number.
Call (786) 321-4970 for an exact quote. Estimates are free.
We Also Serve Cities Near Coral Gables
Our crews work throughout Miami-Dade. If you are in Coral Gables proper, Miami, Key Biscayne, Miami Beach, or Hialeah, the same written-price discipline, Board of Architects expertise where applicable, and documented photo record apply. Dispatch and scheduling are coordinated from our Miami office.
Serving Coral Gables, FL - Our Local Coverage Area
We’re based in the Coral Gables 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 Coral Gables
The Board of Architects’ Mediterranean Revival design review adds four to eight weeks that simply do not exist in neighboring cities. Every exterior addition must clear mandated barrel-tile profiles, stucco detailing, and color palettes before a single permit is pulled. We build this buffer into every written timeline so the customer knows the real calendar before signing. Call (786) 321-4970 for a timeline with the review buffer included.
Materials, not labor. Custom millwork, architectural glass, specialty finishes, and reclaimed or custom-profile barrel tile ordered to satisfy Board of Architects review drive the schedule. Our crew can frame in weeks; the specified materials may take months. The written scope locks the price while we wait. Call (786) 321-4970 to review lead times for your specific finish package.
Yes, but it requires stonework specialists familiar with historic South Florida limestone. Miami oolitic limestone is porous and structurally irregular; standard modern masonry anchors will not hold. On a 1940s Mediterranean Revival home near the Granada neighborhood, our crew opened the rear wall and found structural coral rock that required specialist intervention before we could set the rough-in. The Board then required reclaimed barrel tile to match the adjacent contributing property. The budget held because the scope, allowances, and change orders were fixed in writing before the discovery. Call (786) 321-4970 to schedule a site evaluation.
Because the permit cannot be pulled until the Board of Architects approves the design, and the Board’s standards are aesthetic, not just code-based. We have seen code-compliant submittals rejected for tile curvature mismatch. Pulling a permit early or ordering materials before Board approval risks a full restart. We sequence: Board first, permit second, procurement third. Call (786) 321-4970 and we will walk you through the exact sequence for your project.
The written price is fixed before work starts; the change-order discipline handles the rest. If the Board requires reclaimed tile or a stucco profile change, the allowance was already in the scope. If the restart exceeds the allowance, the change order is signed before any new work proceeds. No surprise, no verbal promise. Under the Haven Standard, Clause 1 is the written price, and no change moves without documentation. That is how we have kept projects within a few percent of the agreed number since 2007. Call (786) 321-4970 for a written quote with allowances built for Coral Gables conditions.
Ready to price your project? Call (786) 321-4970 to schedule your free estimate. Grant Rowan or a member of our team will visit your Coral Gables property, assess the specific conditions - Board of Architects timeline, foundation needs, existing substrate - and deliver a flat written price with scope, allowances, and warranty before any work begins. The 365-Day Done Right Promise applies to every project: if it is not done right, we make it right.
Written by Grant Rowan, Owner at Rowan Construction Group, serving Coral Gables since 2007.