Free written scope consultation - allowances, timeline, and change-order rules on paper before a single trade is scheduled
Fast, Reliable Home Additions & ADU Across Lauderdale-by-the-Sea
A home addition or ADU in Lauderdale-by-the-Sea typically runs $45,000-$130,000 for room additions and $90,000-$220,000 for detached ADU construction, with most projects requiring coastal-spec materials and concrete remediation before new framing begins. We’re Rowan Construction Group, and our crews work the 0.7-square-mile strip between the Atlantic and the Intracoastal regularly - dispatching from our South Florida office to jobs from El Prado to the Anglin Pier. If you’re adding square footage to a 1960s CBS cottage or converting a garage near the reef, the salt air has already started its work on your rebar. Call (754) 254-7676 to schedule your free estimate; we’ll put the number in writing before anyone picks up a tool.
Why Rowan Construction Group Fort Lauderdale Is Lauderdale-by-the-Sea’s Preferred Home Additions & ADU Company
We’ve delivered 4,000-plus projects since 2007, every one with a written price before work started and a documented photo record when the crew left. Lauderdale-by-the-the-Sea homeowners find us because they read the three-star reviews and want a contractor who shows change orders, not just enthusiasm.
Our response time to Lauderdale-by-the-Sea is same-day for estimates - we know the local height ordinances, the Broward County permitting corridor, and which inspectors will flag a standard galvanized fastener on coastal stock. Under Clause 1 of The Haven Standard, your quote arrives as a flat price with written scope; no “call for pricing” and no verbal ballpark.
The 365-Day Done Right Promise backs every job: if it’s not done right, we make it right, with the terms printed on every page. Our background-checked, uniformed crews carry marine-grade hardware specs for this market specifically - not the inland Broward inventory that fails here.
Our Home Additions & ADU Services in Lauderdale-by-the-Sea

ADU Design & Permitting
Every Lauderdale-by-the-Sea ADU starts with a site survey that checks for chloride-induced rebar corrosion in the existing structure - a line item inland Broward ADUs rarely carry. Because the town caps most buildings near 35 feet and is essentially built out, your ADU is almost certainly a remodel of 1950-1985 CBS oceanfront stock, not new ground-up construction. We handle the Florida DEP and Army Corps environmental review requirements triggered by the near-shore coral reef, including turbidity barriers and stormwater controls that most inland builders have never specified. The permit package includes HVHZ product approvals for impact-rated glazing and reinforced roof-to-wall connections - mandatory here, optional elsewhere.

Garage Conversion ADU
Garage conversions in Lauderdale-by-the-Sea run $30,000-$80,000, and the variance depends on what we find when we open the walls. On a two-story CBS duplex a block off El Prado, our crew opened what was supposed to be a simple garage conversion ADU and found the original mild-steel rebar in the ocean-facing wall already spalled with concrete cancer - the door anchor bolts and the original aluminum window frames had corroded to the point of crumbling. We pivoted the scope: stainless and hot-dip galvanized anchors, impact-rated HVHZ glazing, and marine-grade sealed paver joints at the new entry, with a written change order before we framed. The punch list passed inspection sign-off first pass, and the ADU has held through two summers of salt air without a single rust bleed. That’s the difference between a contractor who knows Lauderdale-by-the-Sea and one who treats it like Oakland Park.

New Detached ADU
A new detached ADU in Lauderdale-by-the-Sea means building to HVHZ standards on a lot where the existing structure has already endured decades of salt-air infiltration. We spec stainless or hot-dip galvanized fasteners, marine-grade aluminum or fiberglass window frames, and sealed paver joints at all hardscape transitions - the coastal-spec package that adds 8-15% to material costs but prevents the fastener failure and frame corrosion we see in five-year-old inland-spec work. The foundation ties into existing utilities through concrete that may need spall repair before trenching begins. We pull permits, schedule inspections, and deliver the documented photo record as standard - not an upgrade.

Junior ADU & Interior Conversion
Junior ADUs and interior conversions in Lauderdale-by-the-Sea often involve subdividing 1950s-1980s CBS units where original rebar is already carbonated from salt-air exposure. Before we fur out walls or run new plumbing rough-in, we assess the substrate for concrete cancer - because framing over corroded rebar just hides the problem until the spall pushes through your new drywall. Our written scope separates remediation from finish work so you see exactly where the money goes. Under The Haven Standard, no change proceeds without a signed change order, which is why our projects finish within a few percent of the agreed price.

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.
Before
AfterTrusted Brands We Service in Lauderdale-by-the-Sea
We source across fifty-plus vetted brands, and for Lauderdale-by-the-Sea’s coastal conditions we regularly specify Kohler fixtures with PVD finishes that resist salt corrosion, Moen marine-grade hardware for wet-area ADUs, and Delta H2Okinetic shower systems where water pressure varies across the town’s aging supply lines. Our local inventory includes impact-rated window and door assemblies from approved HVHZ manufacturers - not the standard Miami-Dade County product that fails inspection here. Because we stock for this market specifically, lead times on coastal-spec materials run shorter than if your contractor is ordering inland-grade inventory and hoping the inspector doesn’t notice.
Common Home Additions & ADU Problems We See in Lauderdale-by-the-Sea Homes

- Concrete cancer behind new framing. Original 1950s-1980s CBS walls get furred, framed, and drywalled over corroded rebar without spall repair - the chloride-induced corrosion keeps eating the structure behind your new ADU until the finish cracks and the anchors fail. We assess the substrate before we frame, and we write the remediation into the scope.
- Inland-spec fasteners in salt air. Cheap galvanized fasteners and mild-steel anchor bolts installed by out-of-area crews pit and fail within a few years of Lauderdale-by-the-Sea’s exposure - well before the addition’s finish warranty matters. We spec stainless or hot-dip galvanized for every coastal application, and we document the hardware grade in your photo record.
- Reef-zone stormwater violations. ADU concrete pad work or utility trenching done without turbidity barriers near the offshore reef triggers Florida DEP and Army Corps review delays, fines, and rework. We’ve permitted through this process before; it’s in our standard Lauderdale-by-the-Sea checklist.
- HVHZ non-compliance on window and door packages. Standard-impact glazing that passes in Fort Lauderdale or Wilton Manors fails inspection in Lauderdale-by-the-Sea’s High Velocity Hurricane Zone. We specify only product-approved assemblies, and we pull the permit ourselves so the inspector sees our name on the application, not yours.
Pricing for Home Additions & ADU in Lauderdale-by-the-Sea, FL
A typical home addition in Lauderdale-by-the-Sea runs $45,000-$130,000; ADU construction runs $90,000-$220,000; and garage conversions run $30,000-$80,000. The gap between low and high end is almost always remediation - spall repair, rebar replacement, and structural reinforcement of CBS walls that inland contractors don’t encounter. Coastal-spec fasteners, marine-grade finishes, and HVHZ-rated glazing add 8-15% to material costs compared to the inland-spec version of the same job. But the cheap spec costs more within a decade when the corroded anchors fail and the window frames bleed rust onto your new stucco.
| Service | Price Range in Lauderdale-by-the-Sea |
|---|---|
| Home Addition | $45,000-$130,000 |
| ADU Construction | $90,000-$220,000 |
| Garage Conversion | $30,000-$80,000 |
| Impact Window Installation | $8,000-$25,000 |
| Paver Patio Installation | $3,500-$11,000 |
Every quote is a flat price with written scope and written warranty - Clause 1 of The Haven Standard. Bring a competitor’s written estimate and we’ll review it line by line at no charge. Call (754) 254-7676 for your free estimate.
We Also Serve Cities Near Lauderdale-by-the-Sea

Our Home Additions & ADU crews work throughout coastal Broward County, including Lauderdale-by-the-Sea, Fort Lauderdale, Wilton Manors, Oakland Park, and Lauderdale Lakes. Each market gets its own material spec and permitting approach - what’s right for inland Lauderdale Lakes is not right for salt-frontage Lauderdale-by-the-Sea, and we quote accordingly.
Serving Lauderdale-by-the-Sea, FL - Our Local Coverage Area
We’re based in the Lauderdale-by-the-Sea 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 Lauderdale-by-the-Sea

Yes - typically 10-20% more for the same square footage, because Lauderdale-by-the-Sea’s 1950-1985 CBS stock almost always needs spall repair and rebar remediation before new framing begins, and because HVHZ-rated materials and coastal-spec fasteners cost more than the inland-grade equivalents. Oakland Park ADUs rarely carry the concrete cancer line item or the DEP reef-zone permitting requirements. Call (754) 254-7676 for an exact quote on your specific property - estimates are free.
Standard galvanized fasteners pit and fail within three to five years of Lauderdale-by-the-Sea’s salt-air exposure, while stainless or hot-dip galvanized hardware lasts the design life of the structure. We’ve removed failed inland-spec anchors from five-year-old additions near El Prado - the rust bleed had already stained the new stucco and compromised the structural connection. The coastal-spec upgrade adds roughly 8-12% to fastener costs and prevents a $4,000-$8,000 remediation later. Call (754) 254-7676 and we’ll show you the difference in your written quote.
The near-shore coral reef - one of the most accessible in the continental U.S. - triggers Florida DEP and Army Corps environmental review for any coastal-zone construction that disturbs soil or creates stormwater runoff. Your garage conversion’s new concrete pad, utility trenching, or even significant grading may require turbidity barriers and sediment controls that inland Broward builders have never specified. We include this permitting pathway in our standard Lauderdale-by-the-Sea scope; contractors who don’t know the reef requirement often face stop-work orders and costly redesigns. Call (754) 254-7676 to schedule your free estimate.
Yes - all ADUs in Lauderdale-by-the-Sea require a building permit through Broward County, and junior ADUs must meet Florida’s residential code for egress, ceiling height, and separate cooking facilities. Because the town’s height ordinances have preserved so much aging stock, inspectors here are particularly rigorous about structural load paths and HVHZ compliance in converted spaces. We pull the permit, schedule inspections, and deliver the signed-off documentation as part of your project closeout. Call (754) 254-7676 to review your specific property.
We investigate before we quote - concrete sounding for rebar corrosion, moisture mapping, and structural assessment of the existing CBS walls - so the remediation is in the original written scope, not a mid-project surprise. Under The Haven Standard, no work proceeds on a change until the change order is signed, which means you see every dollar before it’s spent. Our projects finish within a few percent of the agreed price because we measure twice and quote once. Call (754) 254-7676 for a free estimate with written scope.
Ready to add square footage to your Lauderdale-by-the-Sea property? Call (754) 254-7676 to schedule your free estimate. We’ll deliver a flat written price with scope, warranty, and documented photo record - the same way we’ve handled 4,000-plus projects since 2007. Ask about our Free Second Opinion on any competitor’s written estimate; we’ll review it line by line at no charge.
Written by Grant Rowan, Owner at Rowan Construction Group, serving Lauderdale-by-the-Sea since 2007.







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