Key Biscayne

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Market snapshot · Pricing by tier · Since 2016 · Why Key Biscayne trades differently · Key Biscayne vs. Coconut Grove · Elevation and flood · Condo inspections and reserves · The building generations · Boundaries and sub-areas · History · Buyer guide · Method and sources

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Market snapshot: what Key Biscayne condos sell for

Key Biscayne condominiums traded at a median of $887 per square foot over the trailing twenty-four months, across 351 qualifying arms-length sales, at a median price of $1,275,000 and a median residence size of 1,547 square feet. The highest single recorded transfer in that window was $15,200,000.

Those figures describe every one of the 57 Key Biscayne buildings in the Index, which is the same set listed at the foot of this page. That matters, because the submarket is not one market. Read the tier table below before treating the median as a description of any particular building.

Figures are computed from Miami-Dade County recorded transfers — the county's own arms-length qualification, not listing data, and not our estimate. The record runs back to 1972, across 18,311 arms-length transfers.

Key Biscayne condo prices by tier

The single median hides the spread. Splitting the 57 buildings at $2,000,000 median per-unit just value — the appraiser's own assessment, not a judgement of ours — gives two markets that barely overlap.

Tier	Buildings	Sales (24 mo)	Median $/sf	Median price
Upper	10	58	$1,612	$4,500,000
Lower	47	293	$819	$1,195,000
All Key Biscayne	57	351	$887	$1,275,000

The upper tier trades at 2.0× the lower tier. Any figure quoted for "Key Biscayne" without saying which tier it describes is close to meaningless.

What Key Biscayne has actually done since 2016

Two series, because the raw one is not a trend measure. When a new tower delivers, its sponsor closings enter the record at once and at prices unlike anything resale stock is doing — so the raw median moves with the delivery calendar as much as with the market.

The same-cohort series removes that: it counts only buildings delivered in 2009 or earlier (55 of the 57 here), and only from the third year after delivery onward. Same buildings, start to finish.

Year	Raw median $/sf	Same-cohort median $/sf
2016	$616	$603
2017	$578	$569
2018	$589	$561
2019	$530	$510
2020	$548	$536
2021	$627	$612
2022	$843	$827
2023	$880	$872
2024	$856	$841
2025	$874	$849

Change 2016 → 2025	Nominal	Real (CPI-U)
Raw	+41.9%	+5.7%
Same-cohort	+40.8%	+4.9%

For reference over a comparable span, the S&P CoreLogic Case-Shiller National index rose roughly 33% in real terms and its Miami metro index roughly 51%. Most American housing markets gained ground in this period; the question for any submarket is whether it beat that, not whether it rose.

2026 is a partial year and is excluded from the change calculation above.

Why Key Biscayne trades differently from the rest of Miami

Key Biscayne is the only Miami submarket that is simultaneously supply-fixed, single-access, self-governing, and almost entirely in a mandatory flood-insurance zone. The first three support price; the fourth works against it, and the past decade suggests the fourth has been winning.

Fixed supply, and it is genuinely fixed

The island is built out. Fifty-five of the Index's 57 buildings predate 2010; only Oceana (2014) and 101 Sunrise (2015) have been added since. Two state and county parks — Bill Baggs Cape Florida at the southern tip and Crandon Park at the northern end — consume a substantial share of the island's land and are not developable. The Village of Key Biscayne, incorporated in 1991, has zoning and height limits considerably more restrictive than unincorporated Miami-Dade would have applied.

The result is a market where new inventory is not a variable. That is the cleanest supply story of any corridor in this series — cleaner than Coconut Grove's, because the Grove still has a pipeline and the island does not.

One road

Key Biscayne is reached only by the Rickenbacker Causeway. Everything — commuting, deliveries, emergency services, hurricane evacuation — passes over a single connection, and the causeway's condition and eventual replacement have been a live public question for years. For a buyer this is genuinely double-edged. The single access point is a large part of what makes the island feel separate from Miami; it is also a concentrated infrastructure dependency and an evacuation constraint that no other corridor in this series carries.

The flood exposure

Every one of the thirty-three Index buildings on Key Biscayne sits in a Special Flood Hazard Area — there is no Zone X inventory here at all. The Index resolves all thirty-three to Zone AE at base flood elevations of 7 to 10 feet, but FEMA's National Flood Hazard Layer shows VE — the coastal high-hazard designation, which carries wave action — along the Atlantic beachfront. See elevation and flood.

This is close to the inverse of Coconut Grove, where the typical Index parcel resolves to Zone X, and it is the sharpest physical contrast available between two Miami submarkets that trade within 60% of each other on price per foot.

The trade-offs

The island's stock is old. Thirty-eight of 57 buildings predate 1982, and five of the six largest by unit count are 1971–1981 — which puts them squarely in the post-Surfside inspection and reserve regime at the point where it bites hardest. The corridor also lost the Miami Open from Crandon Park in 2019, removing an annual event that had been a fixture since 1987.

And the returns have been modest. On the same-cohort series, Key Biscayne gained 7.6% in real terms since 2016 — positive, but well under the national market and under every other Miami corridor we have measured on the same basis except Sunny Isles.

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Key Biscayne vs. Coconut Grove

Key Biscayne trades at roughly a 36% discount to Coconut Grove on price per foot, with a comparable median residence size — and the two corridors sit at opposite extremes of Miami's flood-zone map.

	Key Biscayne	Coconut Grove
Median $/sf, last 24 mo	$942	$1,481
Median sale price	$1,520,000	$2,000,000
Median residence	1,750 sf	1,661 sf
Qualifying sales, last 24 mo	271	201
Buildings	33	27
Buildings delivered since 2010	2	6
Typical FEMA zone	AE / VE — all in a Special Flood Hazard Area	Zone X
Since 2016, same-cohort real	+7.6%	not yet computed
Access	Single causeway	Street grid

The size comparison is the useful one here. These two corridors sell residences of nearly the same median size — 1,750 square feet against 1,661 — which makes their per-foot figures more directly comparable than most pairs in this series. A 36% per-foot gap between two similarly-sized products, eight miles apart, is a real gap.

What we cannot tell you is why. Elevation, flood zone, access, stock age and governance all differ between these two places, and nothing in the recorded-sales record separates their effects from one another or from transaction mix. The same-cohort row is also not yet symmetrical — we have computed it for Key Biscayne and are backfilling Coconut Grove.

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Key Biscayne flood zone and elevation

Every Key Biscayne building carried in the Index sits in a Special Flood Hazard Area, which triggers the mandatory-purchase requirement for federally backed lending. The Index resolves all thirty-three parcels to Zone AE at base flood elevations of 7 to 10 feet — but FEMA's National Flood Hazard Layer shows VE, the coastal high-hazard zone, along the Atlantic beachfront, and we are reconciling that discrepancy.

Why VE matters if your building is in it. VE designates areas subject to wave action. It carries construction requirements AE does not — open pile or column foundations, no solid perimeter walls below base flood elevation — and it generally prices higher. A buyer on the beachfront should establish which designation applies to their specific parcel rather than accept either this page or the Index.

Confirm the zone and base flood elevation for any specific building before relying on it. Flood zone is a parcel-level determination that changes with FEMA remapping. Check the FEMA Flood Map Service Center and Miami-Dade's flood zone lookup directly. Nothing on this page is a flood determination for any particular property.

What Zone AE means here, precisely

Two things complicate the intuitive reading, and both matter more than the zone letter:

FEMA no longer prices by flood zone. Under Risk Rating 2.0, fully in force since April 2023, rates turn on flood frequency, flood type, distance to a water source, elevation and cost to rebuild. The zone governs whether purchase is mandatory; it does not set the price.

In a condominium, the master policy absorbs it. The building's flood coverage generally sits in the association's RCBAP and reaches the owner as an assessment rather than a premium. Where that policy carries at least $250,000 per unit, the mandatory-purchase requirement is satisfied at the building level and the unit owner's lender requires nothing further.

Price this at the building, from the association's actual policy and budget, not from the flood map. For oceanfront towers, windstorm is the larger line, and on a barrier island it is larger still.

The exposure that is not on the flood map

Two risks specific to this island are not captured by a zone designation and deserve stating plainly:

Storm surge and the single causeway. Key Biscayne evacuates over one road. That is an operational constraint during a storm event and a factor in insurance and lending underwriting that no flood zone letter conveys.

Long-run sea level. The island is low, and unlike Coconut Grove it has no ridge. Regional projections run to several feet over the next century. The Village has undertaken adaptation planning; a buyer holding for decades rather than years should read it directly rather than rely on any summary, including this one.

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Condo inspections and reserves: the island's central diligence question

Key Biscayne has the oldest condominium stock of any corridor in this series. Eighteen of thirty-three Index buildings predate 1982, including five of the six largest. Every one of them is well past the thirty-year milestone trigger, and this is the corridor where post-Surfside compliance status most deserves to be the first question a buyer asks.

Past thirty years and among the largest: Towers of Key Biscayne (recorded 1971; instruments 1972–74; 528 residences), Key Colony 4 (1981, 292), Emerald Bay at Key Colony (1980, 283), Key Colony No. 1 (1978, 282), Casa Del Mar (1971, 235), Commodore Club (1971, 185) and Commodore Club West (1973, 184).

The framework in brief: milestone inspections under s. 553.899, Fla. Stat. for buildings of three or more habitable stories, generally by December 31 of the year the building turns thirty and every ten years after, with a local option for twenty-five years where circumstances including proximity to salt water justify it. (The widely repeated "within three miles of the coastline equals twenty-five years" rule was SB 4-D's original 2022 formulation and was replaced by SB 154 in 2023 at the state level. It survives in Miami-Dade's own county program — and on a barrier island, the county program is the one to read.) Structural Integrity Reserve Studies under s. 718.112(2)(g) at least every ten years, with pre-July-2022 associations required to have completed one by December 31, 2025. The reserve-waiver prohibition, effective for budgets adopted on or after December 31, 2024, with a limited pause available through 2028 under HB 913 (2025). And in parallel, Miami-Dade recertification under County Code § 8-11(f).

Full framework and the document request list: post-Surfside condominium diligence.

A building of 528 residences from 1971, on saltwater, carries a different reserve arithmetic from a building of 93 residences from 1998. The recorded-sales record carries no association-compliance field, so public pricing data does not separate funded buildings from unresolved ones. Verify current milestone and SIRS status, reserve funding, and pending special assessments directly from the association's official records before contracting. On this island that is not a formality.

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The building generations

Key Biscayne's condominium stock arrived in two concentrated waves — 1965–1981 and 1996–2002 — with almost nothing before, between, or since.

1965–1981: the Mackle-era island

The island's first residential build-out produced the large Crandon Boulevard and Ocean Lane inventory that still holds most of its residences. Key Cassa (1965), Sands of Key Biscayne and Villaharbour (1969), Towers of Key Biscayne, Casa Del Mar and Commodore Club (1971), Key Biscayne One Hundred and Commodore Club West (1973), Commodore Club South, Mar-Azul and Grapetree Townhouse (1974), Cape Florida Club (1977), Key Colony No. 1 and 150 Sunrise (1978), Gardens of Key Biscayne and Emerald Bay (1980), and Key Colony 4 and Ocean Lane Plaza (1981).

Key Colony is the defining development of this era. Three of its four phases are carried in the Index — Key Colony No. 1 (1978), Emerald Bay (1980) and Key Colony 4 (1981) — totalling 857 residences, roughly 22% of the island's Index inventory. Key Colony No. 2 at 251 Crandon Boulevard, of comparable size, is not currently carried in the Index; the corridor figures on this page exclude it.

1996–2002: the Ocean Club

The island's second wave is essentially one project. The Ocean Club — Grand Bay Residences (1996), Resort Villa Two (1997), Club Tower One, Club Tower Two, Lake Villa Three and Resort Villa One (1998), Club Tower Three and Grand Bay Tower (1999), and Ocean Tower Two, Lake Villa One, Lake Tower and Ocean Tower One (2001–2002), plus Lake Villa Two (1996) — is a single gated, amenitised master plan built out over six years on the former Mackle land.

It is the reason the corridor's upper tier exists, and its buildings hold six of the corridor's top eight per-foot positions — the two exceptions being Oceana and 101 Sunrise.

2014–2015: the two additions

Oceana Key Biscayne (2014) — Arquitectonica for Consultatio, 153 residences, and the corridor's per-foot leader at $2,489. It is the same developer-and-architect pairing as Oceana Bal Harbour. (The commissioned Jeff Koons sculptures associated with the Oceana name are at the Bal Harbour building; we have found no evidence of Koons work at the Key Biscayne property, and published copy conflating the two is common.)

101 Sunrise (2015) — eleven residences, the corridor's smallest building.

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Boundaries and sub-areas

Key Biscayne is a single barrier island south of Miami Beach, reached only by the Rickenbacker Causeway. The Village occupies the middle; parks occupy both ends.

Crandon Boulevard is the island's spine and holds most of the inventory, including the entire Ocean Club and the Key Colony phases.

Ocean Lane Drive and Ocean Drive hold the older oceanfront stock — Commodore Club, Commodore Club South and West, Ocean Lane Plaza, Key Biscayne One Hundred, Casa Del Mar, Sands of Key Biscayne and Oceana.

Sunrise Drive, Harbor Drive and the Grapetree/Seaview enclaves hold the small-building and townhouse inventory.

Crandon Park at the north and Bill Baggs Cape Florida State Park at the south bracket the residential village and are the reason the island cannot grow.

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History

Key Biscayne carries what Florida State Parks describes as the oldest structure in Miami-Dade County still standing on its original site, and one of the most significant and least-known sites in the history of American emancipation.

The Cape Florida Lighthouse

Congress appropriated funds in 1822; the sixty-five-foot brick tower was completed in 1825 and first lit on 17 December 1825. It was attacked and burned during the Second Seminole War in 1836, rebuilt in the 1840s, and raised to its present ninety-five feet in 1855 after an inspection by Lt. George G. Meade, when a second-order Fresnel lens was installed. Florida State Parks describes the rebuilt tower as the oldest standing structure in Miami-Dade County — a claim best stated as oldest still standing on its original site, since the Fort Dallas coquina barracks of 1844 is older but was disassembled and moved to Lummus Park in 1924.

The rebuild year is given as 1846 by Florida State Parks and 1847 by other sources; we report the state park's date.

From 1888 to 1893 the Biscayne Bay Yacht Club leased the lighthouse as its clubhouse for one dollar total, billing itself as the southernmost yacht club in the United States and the tallest in the world. The same club now sits at the head of the Coconut Grove condominium corridor.

Cape Florida and the route to the Bahamas

The most significant history on this island is the least marketed. Cape Florida was a documented departure point for freedom seekers escaping slavery by sea to the British Bahamas, principally in the early 1820s — a southbound counterpart to the northern Underground Railroad. The site is recognised by the National Park Service's National Underground Railroad Network to Freedom.

The irony is exact and worth stating: the Network to Freedom marker records that construction of the lighthouse by the federal government in 1825 effectively closed the escape route. The structure the island uses as its emblem is the instrument that shut it.

This is a matter of federal designation and scholarship, not local colour, and it is the single most consequential fact about the ground the island sits on.

The causeway, the parks, and the Village

The Rickenbacker Causeway opened in 1947, following a land arrangement with the Matheson family whose coconut plantation had occupied much of the island — the transfer that produced Crandon Park. The causeway made residential development possible; the parks capped it.

Richard Nixon's "Florida White House" operated at 500 Bay Lane from 1969 through 1974, which put the island in the national frame for five years. The house was demolished in July 2004; nothing of it survives.

Hurricane Andrew struck in August 1992 and did severe damage to the island's building stock and tree canopy — an event still visible in the renovation history of the 1970s inventory.

The Village of Key Biscayne incorporated in 1991, and the incorporation is the reason the island's zoning is what it is. Residents sought control over density and height that unincorporated county government had not provided.

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Buyer guide

How ownership works here

The corridor's transaction record is deep but concentrated in old, large buildings. 18,311 arms-length transfers across 57 buildings, with Towers of Key Biscayne alone accounting for 1,651 of them. In the large 1970s buildings a buyer has genuine comparables; in the twelve-to-seventeen-residence buildings, multi-year gaps between recorded sales are normal.

Reserve and assessment position is the transaction variable that most deserves attention here, given the stock age. See inspections and reserves.

Entity ownership and homestead. As across Miami-Dade, a meaningful share of transfers record to LLCs and trusts. Certain entity forms cannot claim Florida's homestead exemption or the Save Our Homes 3% cap. See Save Our Homes, explained.

Carrying costs on a barrier island run above the mainland. Windstorm is the largest line; association flood coverage comes through assessments; reserve funding under the post-2024 rules applies. Run the transactional side through the Miami buyer and seller closing cost calculators.

Schools

Key Biscayne sits within Miami-Dade County Public Schools. Attendance boundaries change and are not reliably inferable from an address; verify current assignment through the M-DCPS school locator before relying on it. We do not rate schools in these guides and do not treat school assignment as a market variable. Independent school options are best evaluated directly with each school's admissions office.

Run the numbers

• Miami Buyer Closing Cost Calculator
• Miami Seller Closing Cost Calculator
• Capital Gains Tax Calculator
• Closing Costs Compared Across Markets

Related guides

• The Roebling Index — Miami · Key Biscayne in the Index
• Coconut Grove · South of Fifth · Brickell · Surfside & Bal Harbour · Sunny Isles Beach
• Post-Surfside Condominium Diligence
• Florida's Save Our Homes Cap, Explained
• Tax Residency Planning · Manhattan vs. Miami · The Foreign Buyer's Overview

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Method and sources

Pricing figures are computed from Miami-Dade County recorded transfers, not from listing or MLS data. We include only transfers the Property Appraiser qualifies as arms-length, with a recorded consideration of $100,000 or more and a recorded residence size, across the 33 Key Biscayne buildings carried in the Roebling Index. Excluded: sponsor deeds recorded at nominal consideration, related-party and portfolio transfers, and corrective deeds.

Two series are published. The raw annual median covers all qualifying sales. The same-cohort series covers only buildings delivered in 2009 or earlier — 31 of the corridor's 33 — and only their resales from the third year after delivery onward. On this island the two series track closely, because almost no new inventory has been delivered. Neither is a repeat-sales index; neither controls for floor, line, view or condition.

Inflation adjustment uses CPI-U annual averages, with 2026 measured at the April index. Comparative national and metropolitan figures are from the S&P CoreLogic Case-Shiller indices deflated on the same basis. Building facts, year built, residence counts and FEMA flood zone are as resolved by the Miami-Dade Property Appraiser.

Known open items: the AE-versus-VE discrepancy on the Atlantic beachfront parcels, which we are reconciling against FEMA's National Flood Hazard Layer; the absence of Key Colony No. 2 from the Index; the recorded-instrument dates for Towers of Key Biscayne (1972–74 against the Index's 1971); developer and architect attributions for the Ocean Club phases and the 1970s Key Colony buildings, which the Index does not carry; the Village's current adaptation-planning status; and building-level homestead-exemption rates, which we have not yet run.

Download: the building-level trailing-24-month table and both annual series are available as a CSV, under the terms on our data usage page.

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Corey Cohen, Principal · The Roebling Team at Compass 646.939.7375 · c.cohen@compass.com

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This page reflects publicly available information and The Roebling Team's transaction experience. FEMA flood zone designations are parcel-level resolutions and must be confirmed against current FEMA and Miami-Dade mapping before any purchase decision. The Roebling Team at Compass does not represent the buildings, associations, schools, parks, or other institutions referenced herein. Florida condominium structural-inspection and reserve law has been amended in every legislative session since 2022; nothing here is a statement of any particular association's compliance status. This page is informational and is not an offer, a solicitation, a valuation, or legal, tax, or investment advice. The Roebling Team is licensed in New York; Florida brokerage services are provided through Compass Florida, LLC. © 2026 The Roebling Team at Compass.