A single-family home in Key Biscayne (zip code 33149) is selling for roughly $1,040 per square foot in early 2026—up about 27 percent from a year earlier, according to Redfin. That number hides two very different markets. Waterfront and updated single-family houses are trading with medians in the high three to four million range, while older condos sell well below that. So the real answer to what your Key Biscayne home is worth depends almost entirely on which of those two markets you’re sitting in.
Why does one Key Biscayne number never tell the whole story?
Key Biscayne is one zip code, but it behaves like two entirely different markets stacked on the same island. On one side are single-family homes—many of them waterfront or recently rebuilt—where buyers compete on lot size, dockage, elevation, and finish. On the other side are condos, where a 1970s building on Crandon Boulevard and a newer low-density development can carry almost the same address but wildly different values.
This is why automated estimates for Key Biscayne properties struggle. A Zillow or Redfin algorithm averages the island’s real estate and produces a number that may not describe a single actual home on it. When you see a headline median jump or fall sharply quarter to quarter, that usually reflects which segment happened to close—not a real swing in your property’s value.
- A handful of large waterfront sales can pull the median up.
- A run of condo closings can pull it down.
- Neither tells you what a buyer would pay for your specific home next month.
What is the Key Biscayne data actually saying in 2026?
Three figures frame the Key Biscayne real estate picture right now:
- The median sale price per square foot in 33149 is about $1,040—up 26.8 percent year over year, per Redfin’s most recent data.
- The zip code’s overall median sale price sits near $2.52 million, which blends houses and condos into one figure.
- Homes in 33149 are taking roughly 92 days to sell (down from 102 days a year ago), signaling steady rather than frantic demand.
The segment split matters more than any single median. Douglas Elliman’s Q3 2025 Barrier Islands report put Key Biscayne single-family medians in the high three to four million range, with condos trading materially lower. As that report makes clear, “one island median can hide very different conditions between waterfront estates and older condos.”
If you own a renovated waterfront house, the per-square-foot trend is working in your favor. If you own an older condo, your home’s value is set by your specific building’s reserves, assessments, and recent comparable sales—not by the island average.
What moves a Key Biscayne valuation up or down?
For single-family homes:
Water frontage and direct ocean or bay access remain the largest single drivers. Beyond that, buyers in this price band are paying for elevation and flood resilience, lot size, a usable dock, and a finish level that is move-in ready. A house that needs a full renovation now trades at a meaningful discount because construction costs and timelines have made buyers far less willing to take on massive projects.
For condos:
Since the structural reforms that followed Surfside, condo value is increasingly a function of the building, not just the unit. Buyers and their lenders are scrutinizing Structural Integrity Reserve Studies (SIRS), recent or pending special assessments, milestone inspection status, and insurance costs.
The New Condo Reality: A beautifully renovated unit in a building facing a large assessment will appraise and sell for less than a plainer unit in a financially healthy building. If you’re selling a condo, knowing your building’s financial position before you list is no longer optional.
How does Key Biscayne fit Miami’s $1M+ luxury market?
Key Biscayne is riding a broader Miami-Dade luxury wave. Single-family sales above $1 million rose 21.34 percent year over year in the first quarter of 2026, climbing from 164 to 199 transactions, according to the MIAMI Association of Realtors. The county’s luxury threshold has now risen to about $4.1 million, and the share of million-dollar-plus homes has grown from 8 percent in 2019 to 28 percent in Q1 2026.
Two forces sit beneath those numbers.
- Wealth Migration: High-net-worth individuals, executive, and family offices continue relocating to South Florida from higher-tax states.
- The Power of Cash: Cash buyers dominate the upper end of the Miami market, which means many Key Biscayne sales are not gated by mortgage rates the way mid-market homes are.
For a seller, that’s the most important context of all. The buyer for your home is more likely to be motivated by lifestyle, security, and tax position than by this month’s interest rate.
So what is my Key Biscayne home actually worth?
The starting point for home valuation in this market is honest segmentation. A waterfront or updated single-family house should be valued against recent single-family closings with similar water access and condition—not against the island-wide median. A condo should be valued against recent sales in the same building or a directly comparable one, with the building’s financial health factored in.
From there, the variables that actually close the gap are condition, view, and how the home is presented and priced on day one. In a market taking about three months to sell, the first two weeks of pricing and positioning carry disproportionate weight.
An online estimate is a starting conversation, not a true answer. The number that matters is the one a real buyer will pay. Obtaining that requires reading your specific segment, your building or block, and the current pool of buyers actively shopping Key Biscayne.
Frequently Asked Questions
How much is a home worth in Key Biscayne in 2026?
The 33149 median sale price is around $2.52 million, but that blends houses and condos. Single-family medians run in the high three to four million range, while condos trade lower. Per-square-foot pricing is near $1,040 and rising, so your value depends heavily on segment and condition.
Are Key Biscayne home prices going up or down?
Per-square-foot pricing in 33149 is up roughly 27 percent year over year. Miami-Dade luxury sales overall rose more than 21 percent in Q1 2026. Island-wide medians can look choppy quarter to quarter based on which segment closes, but the underlying luxury trend has been upward.
Why do online estimates get Key Biscayne so wrong?
Automated tools average a zip code that contains both waterfront estates and older condos. That blended number rarely matches any real home. Accurate valuation here requires comparing your property only to genuinely similar sales, and for condos, accounting for the building’s reserves and assessments.
Do my condo building’s finances really affect my sale price?
Yes, significantly. After recent Florida condo reforms, buyers and lenders examine reserves, milestone inspections, and special assessments closely. A unit in a financially healthy building can sell for noticeably more than a similar unit facing a large assessment, regardless of how nicely either is finished.
Want the real number for your specific home, not an algorithm’s island average?
Barbara Gretsch · Miami Real Estate
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Barbara Gretsch is a REALTOR® with Berkshire Hathaway HomeServices EWM Realty, serving Miami and South Florida’s $1M+ residential market, including Coconut Grove, Coral Gables, The Roads, Brickell, Key Biscayne, and Miami Beach. barbaragretsch.com
SOURCES
Redfin, 33149 Housing Market and Key Biscayne Housing Market
MIAMI Association of Realtors, Miami-Dade Luxury and Ultra-Luxury Price Thresholds Rise, April 2026
Keyes/Illustrated, Luxury Report: High-End Transactions Jump Across South Florida in Q1 2026, via citybiz
Haute Residence, Miami’s $1 Million-Plus Home Sales Are Leading the Market in 2026
Market data current as of June 2026.