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 Palm Beach
A full home addition in Palm Beach runs $45,000 to $130,000, and a new detached ADU typically lands between $90,000 and $220,000 depending on whether you’re building on the ocean side or Intracoastal side of the island. Those numbers are not guesses; they reflect the salt-air hardware, impact glazing, and ARCOM submittal cycles that define construction in the Town of Palm Beach. Barrett & Sons Construction has been building additions and ADUs across Palm Beach for over 29 years, and our crews know which materials pass ARCOM the first time. Call (877) 610-1318 for a free estimate, and Tom Barrett will walk the site with you himself.
Why Barrett & Sons Construction Is Palm Beach’s Preferred Home Additions & ADU Company
Palm Beach is not a typical construction market. The Town’s Architectural Commission reviews every exterior change, and the island’s salt air punishes hardware that would last thirty years inland. Our Home Additions & ADU team spends real time on-site, not on the phone dispatching strangers. Tom Barrett lives close enough to the island that his name and reputation follow every project. That is why so much of our work in Palm Beach comes from referrals on streets like Clarendon Avenue, Seabreeze Avenue, and the South Ocean Boulevard estate stretch.
We answer our own phone, 24/7, with a live person, not a voicemail box or an out-of-state call center. Every scope, allowance, and price change on your Palm Beach addition arrives in writing as a change order before work proceeds. Permits get pulled and inspections get signed on every eligible job, because we know the last contractor most Palm Beach homeowners used told them permits were optional. And every job carries the written 90-Day Done Right Promise: if it isn’t right, one call brings Tom back.
Our Home Additions & ADU Services in Palm Beach
ADU Design & Permitting
An ADU in Palm Beach is a permitting marathon before it is a construction project. ARCOM review alone can add 60 to 90 days to a project schedule, and that is before the town’s building department sees a single drawing. We handle the full design and permitting path: architectural drawings, ARCOM submittal packages, structural engineering, and the permit filings. On a 1920s Mediterranean Revival estate, the commission wants cast-stone detailing and like-for-like materials, not standard Hardie trim. We know what passes, because we have walked projects through ARCOM hearings off Peruvian Avenue and the historic core around Worth Avenue.
Garage Conversion ADU
Garage conversion ADUs in Palm Beach run $30,000 to $80,000, with the lower end for interior-only conversions and the higher end for conversions that involve exterior changes requiring ARCOM review. Many of the island’s older garages sit on original coral-stone or Keystone foundations, and some hold moisture from the shallow water table. We check the slab, the rebar, and the fasteners before we draw a single line. A garage conversion that keeps the original garage door and framing interior walls can often move faster, but if you are adding a doorway or changing the roofline, plan for commission review.
New Detached ADU
A new detached ADU in Palm Beach typically costs $90,000 to $220,000. The spread reflects what the salt air and wind zone demand. On an ocean-facing lot, you need impact-resistant glazing, 316-stainless fasteners, hot-dip galvanized connectors, and a raised slab with a crystalline waterproofing admixture. On an Intracoastal-side lot off Royal Palm Way or Brazilian Avenue, king tides push groundwater up against the slab, so elevation and waterproofing are non-negotiable. We specified all of this on a South Ocean Boulevard estate where the original 1980s sunroom addition had electrogalvanized hurricane clips rusted to orange dust. We re-framed with hot-dip galvanized connectors, specified 316-stainless fasteners, poured a raised slab, and walked the punch list with the owner’s architect before ARCOM sign-off.
Junior ADU & Interior Conversion
Junior ADUs and interior conversions are the fastest path to more living space in Palm Beach, because they often avoid full ARCOM exterior review. If you are converting an existing bedroom suite, a pool cabana, or an upper-floor bonus room into a self-contained living unit with its own entrance and kitchenette, we can help you navigate the town’s specific code requirements for egress, fire separation, and minimum size. These projects still require permits and inspections, but the timeline is shorter than a ground-up detached ADU. Second-story additions on 1920s Mediterranean Revival homes are a specialty of ours. We verify the load-bearing capacity of the original coral-stone base before designing the pop-up, because reusing a foundation without that check leads to shear cracks after the first king-tide cycle.
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 Palm Beach
We install impact-rated windows and doors from PGT and CGI, and we stock the marine-grade hardware and fasteners Palm Beach projects actually require. Simonton and Ply Gem come up on a lot of inland quotes, but on a barrier island, we typically specify PGT or CGI for their Miami-Dade rating and salt-air performance. The brand name on the glass matters less than the rating behind it, and we will show you both in writing before you sign. When you walk into the hardware store on Worth Avenue and ask about the window you just approved, you should be able to look up the model number and see what you paid for.
Common Home Additions & ADU Problems We See in Palm Beach Homes
- Salt-air hardware failure. We regularly see inland-grade electrogalvanized clips and fasteners on Palm Beach additions that have rusted to orange dust within a decade. The fix is 316-stainless or hot-dip galvanized spec, which costs more up front but does not fail after two salt-fog seasons.
- Foundation surprises in older homes. Palm Beach’s 1920s to 1960s estate stock often sits on original coral-stone or Keystone foundations with shallow footings. A second-story addition without a structural check can cause shear cracks after the first king tide, and we have seen it more than once on Intracoastal-side lots.
- ARCOM rejection on standard materials. A garage conversion filed with standard Hardie trim gets sent back for missing cast-stone detailing. The town’s Architectural Commission is strict, and a mis-specified fascia board or an anodized-aluminum railing can stall permits for 60 to 90 days before the building department sees a single drawing.
- Window and frame pitting. Inland-grade aluminum windows facing the ocean start pitting within two seasons under Palm Beach’s salt fog. Impact-rated glazing with a marine-grade finish is not optional on the ocean side; it is the minimum spec that survives.
Pricing for Home Additions & ADU in Palm Beach, FL
Here is what our Palm Beach customers actually pay for the three most common project types:
| Project Type | Typical Price Range in Palm Beach |
|---|---|
| Home Addition | $45,000 - $130,000 |
| ADU Construction | $90,000 - $220,000 |
| Garage Conversion | $30,000 - $80,000 |
The coastal-spec price gap is real, and we want you to understand it before you compare bids. A standard-spec ADU might save $10,000 to $15,000 on paper, but that saving disappears when the windows pit, the fasteners rust, and the railing fails a structural inspection within a decade. In Palm Beach, the salt air decides the materials. We quote the coastal-spec version up front and show you exactly what you are paying for. Every estimate is free, and every price change arrives in writing before work starts. Call (877) 610-1318.
We Also Serve Cities Near Palm Beach
Our crews serve homeowners across Palm Beach and the nearby communities of West Gate, West Palm Beach, Riviera Beach, and Lake Park. If you are on the island or just across the bridge, the same crew, the same written change-order practice, and the same 90-Day Done Right Promise apply. Call us from anywhere in the 33480 ZIP code or the surrounding area.
Serving Palm Beach, FL - Our Local Coverage Area
We’re based in the Palm Beach 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 Palm Beach
Generally no, an interior-only garage conversion with no exterior modification does not require ARCOM review, but the project still needs building permits and inspections, and any change to the roofline, door openings, or exterior finishes does trigger commission review. Call (877) 610-1318 and we will tell you in the first five minutes whether your project needs ARCOM.
Yes, but only if the existing coral-stone foundation is verified for load-bearing capacity first. The original base often looks solid from the outside and has hidden deterioration inside. We bring in a structural engineer before design, and we have done second-story additions on Mediterranean Revival homes where the original base stayed intact and the new framing tied into it with hot-dip galvanized connectors. Call us at (877) 610-1318 for a site assessment.
We specify 316-stainless fasteners and marine-grade railing systems with hot-dip galvanized or stainless structural connectors on oceanfront decks. Inland electrogalvanized hardware rusts to orange dust in Palm Beach’s salt air within a decade, and we have replaced enough of it on South Ocean Boulevard to refuse to install anything less. The spec costs more, but it is the only spec that survives.
The coastal-spec ADU typically costs $10,000 to $15,000 more than the same floor plan with inland hardware, aluminum windows, and standard fasteners. That gap covers impact-rated PGT or CGI glazing, 316-stainless fasteners, hot-dip galvanized connectors, and a raised slab with waterproofing admixture. The standard spec fails in this climate within a decade, and the replacement cost plus ARCOM review time wipes out the initial saving. Call (877) 610-1318 for an exact line-item quote.
King tides push the water table up against the slab, so a detached ADU on an Intracoastal-side lot needs a raised slab with a crystalline waterproofing admixture and proper drainage detailing. The elevation is set by the town’s flood zone requirements, but the waterproofing is what keeps the rebar from corroding and the interior from wicking moisture. We account for both before the first drawing is filed.
Call Barrett & Sons Construction for Your Palm Beach Addition or ADU
If you want a contractor who will put every scope, allowance, and price change in writing before a single nail moves, call Barrett & Sons Construction at (877) 610-1318. We are the owner-operated, name-on-the-truck alternative to national outfits that quote one price on the phone and show up with another. Tom Barrett publishes his name, his address, and his license number. Look it up before you sign anything. Then call us for your free estimate.
Written by Tom Barrett, Owner at Barrett & Sons Construction, serving Palm Beach and the surrounding communities since 1998.