Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Before
After
Before
After
Before
AfterHow Much Does Home Addition Cost in Miami?
A home addition in Miami typically costs between $53,100 and $153,400, depending on size, structural complexity, and the finishes you choose. Most homeowners adding a single-room addition or a master suite land somewhere in the middle of that range. The wide spread exists because a 200-square-foot sunroom addition and a 600-square-foot two-story addition are both “home additions” – they just share very little else in common.
Home Addition Cost Breakdown (2026)
Home addition pricing in Miami is best understood as a stack of line items. The number on your final quote reflects how those layers combine – not a single flat rate per square foot. Below is a breakdown of typical cost buckets for Miami-area additions as of 2026.
| Addition Type or Cost Category | Typical Miami Range |
|---|---|
| Single-Room Addition (bedroom, office, family room) | $53,100 – $89,000 |
| Primary Suite Addition (bedroom + bath) | $72,000 – $118,000 |
| Second-Story Addition | $95,000 – $153,400 |
| Sunroom or Florida Room Addition | $53,100 – $74,000 |
| Bump-Out Addition (extending an existing room) | $53,100 – $68,000 |
| Foundation Work (CBS or stem-wall, per project) | $8,000 – $22,000 |
| Electrical Rough-In and Panel Upgrade | $3,500 – $9,500 |
| Plumbing Rough-In (wet additions only) | $4,200 – $11,000 |
| HVAC Extension or New Mini-Split | $3,800 – $9,000 |
| Impact Windows and Exterior Doors | $9,440 – $29,500 |
| Roofing (tie-in to existing roof, per addition) | $9,440 – $23,600 |
| Interior Finishes (flooring, paint, trim, lighting) | $8,000 – $21,000 |
| Miami-Dade Permits and Inspection Fees | $1,800 – $5,500 |
A few things drive the total significantly. Miami-Dade County sits inside the High-Velocity Hurricane Zone, which means every permitted addition must meet the Miami-Dade Notice of Acceptance (NOA) standards – the strictest wind-load requirements in the continental United States. That affects your structural framing, roof connection hardware (hurricane straps and clips, not optional), and every exterior opening. Impact-rated windows and doors, required by code on any new addition, carry a real cost premium over standard units used in other markets. If your quote is unusually low, the first question is whether it includes code-compliant impact glazing and proper engineered drawings for the building department. At Rowan Construction Group, that documentation is part of the written price – not an afterthought billed separately.
Soil conditions in Miami also affect foundation costs in ways that surprise homeowners who have built elsewhere. Low-lying neighborhoods – parts of Kendall, Hialeah, and much of Miami Gardens – can require additional stemwall height or engineered fill. Rocky limestone substrate in areas like Coral Gables and parts of Pinecrest complicates excavation but can reduce settling concerns. We assess site conditions before writing the number, because a foundation line item that doesn’t reflect actual soil conditions is a change order waiting to happen.
What Affects Home Addition Pricing in Miami
- Square footage and structural type: Cost per square foot ranges from roughly $265 to $435 in the Miami market depending on complexity. A simple single-story slab-on-grade addition sits at the lower end. A two-story addition with a new load-bearing wall opening, a reinforced second-floor deck, and a staircase reconfiguration sits near the top.
- Miami-Dade building code compliance: Every addition in Miami must be permitted through Miami-Dade County (or the applicable municipality – Coral Gables, Miami Beach, and Hialeah each run their own building departments). Engineered drawings, wind-load calculations, product approvals, and multiple inspections are part of every legal project. Skipping permits doesn’t save money; it creates title problems when you sell and creates liability when the next hurricane tests what was built.
- Impact window and door requirements: Miami-Dade’s product approval system requires that every exterior opening in a new addition use glazing with a valid NOA. That means impact windows and impact-rated exterior doors – which, per our 2026 pricing data, run $9,440 to $29,500 depending on count and size. There’s no legal workaround, and there shouldn’t be.
- Roofing tie-in and material: Connecting a new addition’s roof to the existing structure is one of the more technically demanding parts of the project. If the existing roof is aging or uses a different material than what the addition calls for, a full reroofing of the combined area may be necessary. In Miami, concrete tile and metal roofing are the dominant systems – both perform well against wind and rain, but metal costs more upfront and runs $17,700 to $47,200 on larger scopes.
- Wet versus dry addition: Adding a room with plumbing – a bathroom, a kitchenette, a laundry alcove – costs meaningfully more than a dry addition (a bedroom, office, or family room). Rough plumbing in a Miami slab-on-grade home means saw-cutting the existing slab, setting new drains, and patching. That work adds $4,200 to $11,000 before a single fixture is installed.
- Finishes and fixture selection: Interior finishes are where cost swings most dramatically within a single project type. A primary suite addition finished with builder-grade flooring and standard fixtures looks nothing like one finished with large-format porcelain tile, Kohler fixtures, and Cambria or Caesarstone countertops in the bath. Both are valid choices – but the written quote needs to name the spec, not gesture at it. That’s how Rowan scopes every job: the brand, the model, the square footage, the color category, in writing, before anyone starts.
- Site access and lot constraints: Miami lots – particularly in Coconut Grove, South Miami, and the Roads neighborhood – can be narrow, fenced, or landscaped in ways that restrict equipment access. Tighter staging areas add crew time. If the addition is at the rear of a deep lot with no side access, material delivery and excavation equipment routing become a real cost factor that a honest estimate addresses upfront.
BeforeAfterHome Addition Cost by Size: Miami Square-Foot Reference
Square-foot pricing is a starting reference, not a quote. Use it to pressure-test estimates you receive – not to build a budget from scratch.
| Addition Size | Estimated Cost Range (Miami, 2026) | Typical Use Case |
|---|---|---|
| 200 sq ft | $53,100 – $68,000 | Bump-out, sunroom, small bedroom |
| 300 sq ft | $68,000 – $95,000 | Bedroom addition, home office |
| 400 sq ft | $88,000 – $118,000 | Primary suite, family room |
| 500-600 sq ft | $110,000 – $153,400 | Large suite, second-story addition, multi-room |
ADU and Garage Conversion: When a Separate Unit Makes More Sense
Some Miami homeowners who come to us for a home addition realize partway through the conversation that what they actually want is a separate living unit – either for rental income or for a family member who needs some independence. That’s a different product. A detached or attached ADU (accessory dwelling unit) in Miami runs $106,200 to $259,600, which is a significant premium over a standard addition – but it includes a kitchen, full bath, separate entrance, and its own meter, which makes it rentable under Miami-Dade short-term and long-term rental rules.
A garage conversion is the lower-cost path to a similar outcome: $35,400 to $94,400 in Miami, depending on whether the garage is attached or detached, how much insulation and waterproofing is needed, and what finishes are specified. Coconut Grove and Brickell homeowners with detached rear garages are the most common candidates – the structure already exists, so you’re converting rather than building from scratch. The permitting requirements are still real; Miami-Dade requires a full inspection of any space converted to habitable use.
If you’re weighing these options, our Home Addition in Miami service page walks through how Rowan approaches the scoping conversation – including how we help homeowners decide between an addition and an ADU before the quote is written.
Miami Permits: What You’re Actually Paying For
Permit fees in Miami-Dade County are not a formality. For a home addition, expect to pay $1,800 to $5,500 in permit and inspection fees directly to the building department. That number covers the application, plan review, and the multiple inspections required at framing, rough mechanical, insulation, and final. It does not cover the cost of the engineer who produces the stamped drawings – that’s a separate line item, typically $1,500 to $4,000 depending on project complexity.
What you get in return is a CO – a certificate of occupancy for the new space. Without it, the addition doesn’t legally exist as habitable square footage. That matters when you refinance, when you sell, and when insurance adjusts your coverage after a storm. Any contractor who suggests pulling permits is optional is telling you something important about how they work.
At Rowan Construction Group, permits are included in the written scope and managed by our team. The homeowner doesn’t chase the building department – we do. Under The Haven Standard, no work starts until permits are issued, and the photo record we provide after every inspection gives you documentation of exactly what the inspector saw and approved.
How to Save on a Home Addition in Miami
Saving on a home addition is mostly about making decisions early, not cutting corners late. Here’s where the money actually goes and how to control it.
Lock the scope before you sign. Change orders during construction are the primary reason additions go over budget. In Miami’s construction market, mid-project changes are expensive because labor and materials are both in demand and subs don’t hold prices for work that moves. Every change order at Rowan requires your signature before any work is done – that’s not a bureaucratic habit, it’s what keeps the final number close to the agreed number. We’ve delivered 4,000-plus projects this way and it’s why our projects finish within a few percent of the written price.
Choose your finishes before construction starts. Tile, flooring, fixtures, and cabinetry should be selected and ordered before the framing inspection, not after. Long lead times on specific materials – certain Cambria slabs, some Techo-Bloc pavers for an exterior transition, custom cabinet orders through KraftMaid or Wellborn – can stall a project that’s otherwise ready for finish work. Stalled crews cost money.
Don’t over-spec the exterior. The code minimum for Miami is already high – impact windows and hurricane-resistant framing are required, not upsells. You don’t need to go beyond code on the structure. Spend the finish budget on the interior, where the experience of living in the space is actually shaped.
Get a second opinion on any quote you’ve already received. Rowan offers a free review of any written estimate you bring us – line by line, at no charge. This isn’t a sales technique; it’s a useful exercise if you’re not sure whether a low quote is missing something real (like the permit fees, the engineering drawings, or the impact glazing spec). Call (786) 321-4970 to set that up.
Time the project outside peak season where possible. Miami’s construction market tightens between October and March when snowbird-adjacent renovation activity peaks in Coral Gables, Pinecrest, and Miami Beach. Booking a project for spring or summer doesn’t always yield a lower price, but it typically yields better subcontractor availability and faster scheduling. We’ll give you an honest read on timing when you call.
Avoid over-sizing the addition for the lot. Miami-Dade zoning setback rules limit how close an addition can come to the property line – typically five feet on the sides, ten feet in the rear, though this varies by zoning category and municipality. Going right up to the limit has diminishing returns. A 300-square-foot addition that maximizes your usable space is a better investment than a 400-square-foot addition that required a variance and compressed your backyard. We pull the zoning data before writing the scope.
What the Written Price Includes at Rowan
Because “written price” means different things at different companies, here’s exactly what Rowan Construction Group puts in writing before anyone starts work on a home addition.
- Scope of work by trade: framing, foundation, roofing, electrical, plumbing, HVAC, insulation, drywall, flooring, paint, trim, and any specialty finishes
- Material specifications by brand and model where finishes are involved – not “tile TBD”
- Permit and inspection fees, included in the flat price
- Engineering drawing coordination, included in the flat price
- Impact window and door product approvals, specified by NOA number in the scope
- Timeline with milestone dates
- The 365-Day Done Right Promise: if it isn’t right within a year of completion, we make it right – in writing, not as a handshake
No work proceeds on any change until you’ve signed a change order. That’s Clause 1 of The Haven Standard – the administrative discipline that has kept Rowan projects within a few percent of the agreed cost since 2007.
FAQs – Home Addition Cost in Miami
How much does a home addition cost in Miami?
A home addition in Miami costs between $53,100 and $153,400 for most residential projects. Single-room additions on the low end, two-story or multi-room additions toward the top. The range reflects differences in size, structural complexity, permit costs, and finish level – not vague market conditions. Call (786) 321-4970 for a written estimate specific to your address and scope.
How long does a home addition take to build in Miami?
Most Miami home additions take 4 to 7 months from permit application to final inspection. Permitting alone runs 6 to 12 weeks in Miami-Dade County, depending on the municipality and current plan-review volume. Construction itself, once permits are issued, typically takes 10 to 18 weeks depending on addition size. Projects that stall usually do so at one of two points: waiting for permits, or waiting for materials that weren’t ordered early. We build both into the timeline when we write the scope.
Is it cheaper to add up or add out in Miami?
Adding out (a single-story addition) is almost always less expensive per square foot than adding up (a second story), because a second-story addition requires a structural assessment of the existing foundation, reinforced connections, a new staircase, and a more complex roof tie-in. In Miami’s market, single-story additions run roughly $265 to $345 per square foot; second-story additions run $320 to $435 per square foot. The right answer depends on your lot constraints – some Miami lots simply don’t have room to expand outward given setback rules.
Do I need permits for a home addition in Miami?
Yes – every home addition in Miami requires a building permit, engineering drawings, and multiple inspections. Miami-Dade County, and the individual municipalities within it (Miami Beach, Coral Gables, Hialeah, and others), all enforce this. An unpermitted addition creates problems at sale, affects insurance coverage, and can trigger a demolition order if discovered during inspection of another trade. Permit fees typically run $1,800 to $5,500 plus engineering costs. At Rowan, permits are included in the written scope and managed by our team – they’re not an afterthought you handle separately.
What’s the difference between a home addition and an ADU in Miami?
A home addition is attached space that is part of the primary residence – a new bedroom, expanded living area, or primary suite. An ADU (accessory dwelling unit) is a separate living unit with its own kitchen, full bath, and entrance, built on the same lot. ADUs in Miami cost $106,200 to $259,600 and can be rented independently under Miami-Dade rules. A garage conversion is a lower-cost path to a similar outcome, running $35,400 to $94,400. If you’re not sure which makes sense for your property, we walk through the zoning and budget considerations before writing any numbers.
How does Rowan price a home addition before the project starts?
We assess the site, pull the zoning data, review the structural conditions of the existing home, and write a flat price with a full written scope – brands named, square footages specified, permit costs included. Under Clause 1 of The Haven Standard, no work starts without that document in your hands and your signature on it. We’ve done this on every one of our 4,000-plus projects. The written price isn’t a ballpark – it’s the number we’re accountable to, and if anything changes from scope, you sign a change order before we proceed.
Key Takeaways
- Home additions in Miami run $53,100 to $153,400, with most single-room projects falling between $60,000 and $95,000.
- Miami-Dade’s High-Velocity Hurricane Zone requirements – impact windows, engineered framing, hurricane straps – are code minimums, not upsells. They add cost versus other markets and there is no legal workaround.
- Permits cost $1,800 to $5,500 plus engineering. Any quote that excludes them is missing a real cost.
- Wet additions (with plumbing) cost $4,200 to $11,000 more than dry additions of the same footprint.
- ADU construction runs $106,200 to $259,600; garage conversions run $35,400 to $94,400 – both are separate product categories with different code paths.
- A written, flat-price quote with a named scope and signed change orders is the only reliable way to keep a Miami addition on budget.
- Rowan Construction Group offers a free second opinion on any written estimate you’ve already received – call (786) 321-4970.
Get a Written Price for Your Miami Home Addition
If you’re planning a home addition in Miami – whether that’s a single room in Kendall, a primary suite in Coral Gables, or a second story in South Miami – the first useful step is a written number. Not a ballpark, not a range-from-range, but a flat price with a scope attached.
Grant Rowan and the team at Rowan Construction Group have been delivering exactly that since 2007, across Miami and the surrounding market, on every one of our 4,000-plus projects. The home page has an overview of everything we build; call us at (786) 321-4970 and we’ll set up a site visit, assess your property, and give you a written price before anyone picks up a tool.
If you’ve already received a quote from another contractor and want a second set of eyes on it, that review is free. Bring the document and we’ll go through it line by line.
Pricing reflects the Miami market as of 2026. Rowan Construction Group Miami offers free estimates – call (786) 321-4970.
Written by Grant Rowan, Owner at Rowan Construction Group, serving Miami, FL since 2007.
What Our Customers Say
"Driveway replaced properly with a base that will actually last. They explained why the cheaper quote was cheaper."
- Reggie O."Good communication throughout. Weekly written update meant I never had to chase them."
- Nadine G."Solid work, decent crew, and the site was left tidy every evening."
- Pearl A.