Building facts
- Address
- 20 Island Avenue
- Neighborhood
- Belle Isle
- Year built
- 1962
- Floors
- 15
- Status
- Completed
- Pricing
- Starting at $475,000
Verified 17 August 2026Miami-Dade County Property Appraiser1 source

On recorded 2026 sales this building runs $627 per square foot — cheaper than 89 of the 117 buildings on the Miami Condo Index. Figures are closed sales from the Miami-Dade County Property Appraiser, not asking prices. Hover or tap a colour to see the split.
Key Takeaways
- Your tax assessment here will not look like the current owner’s — homes last sold before 2005 are assessed at $269 per square foot; homes bought since 2021 at $507 — 89% higher for the same building.
- 222 homes at 20 Island Avenue on Belle Isle — with no commercial folios at all — unusually clean for a building of this age.
- The county record runs back to 1980 — 878 qualified sales, which is one of the longer continuous records on this site.
- The people who bought at the 1980–83 conversion did extremely well — 151 of them have resold, at a median of +292%.
- The four-year rise is real but I cannot confirm it at constant size — the 897 sq ft floorplate series rests on 9, 6 and 4 sales and shows no clean trend.
- 16.4% of all resales lost money — on 657 of them, at a median gain of 44.9% over a 6.2-year hold.
Belle Plaza, by the numbers
Starting at $475,000. Source: the building record on this site.
20 Island Avenue, Miami, Florida | Neighborhood: Belle Isle, Miami Beach
The thing the price table will not tell you
Most condo pages show you what homes sold for. Here is something the county record shows that almost nobody publishes, and that will affect what this building actually costs you to own.

Florida caps how fast an assessed value can rise for an owner who stays put. Sell, and it resets to market. Across the 222 homes here, that produces a spread you can measure directly:
| When the owner last bought | Homes | 2026 assessed value per sq ft |
|---|---|---|
| Never sold, or before 2005 | 53 | $269 |
| 2005–2014 | 43 | $454 |
| 2015–2020 | 51 | $510 |
| 2021 or later | 75 | $507 |
A buyer since 2021 is assessed 89% higher per square foot than a long-held owner in the same building — $507 against $269. The correlation between holding period and assessment runs at r = +0.534 across all 222 homes, which is strong enough that holding period, not the home itself, is doing most of the work in that spread.
What this means in practice: if you buy here, do not budget from the seller’s current tax bill. The number resets when you buy, and in this building the reset is large. I am deliberately not converting that into a dollar figure, because the millage rate is not in the Property Appraiser’s record and I will not state a tax number I cannot source.
This is not unique to Belle Plaza — it is Florida law, and it applies everywhere. It shows up unusually clearly here because more than a fifth of the building has not changed hands since before 2005.
What is actually inside the building
The county returns 223 folios at 20 Island Avenue: 222 residential homes and a single reference folio. There are no commercial units, no separately deeded parking and no storage folios — nothing has to be filtered out of the figures below, which is unusual for a building of this vintage and makes this record cleaner than most.

The mix is 129 one-bedrooms, 70 two-bedrooms, 22 studios and one three-bedroom. Heated area runs 592 to 1,964 square feet with a median of 897.
102 of the 222 homes — 46% of the building — are exactly 897 square feet. That single repeated floorplate is what makes the analysis further down possible, and it is also a practical advantage: when you price a home here you are usually pricing against physically identical neighbours rather than against loose analogies.
The 2026 assessed values run $115,534 to $1,553,543, with a median of $438,361 — and per the section above, read that range as a record of when people bought as much as of what they own.
The record sale is $2,115,000 in August 2022, for a 1,844 square foot home at $1,147 per square foot — a high-floor line that sits well above the rest of the building.
A record that starts in 1980
The county holds 878 qualified sales here going back to 1980. That is a genuinely long continuous record — long enough to contain the 1980s, the 1990s, the 2000s bubble, the crash and everything since.
131 of those sales fall in 1980–83, at a median of $91,400 and $97 per square foot. That is the conversion era, when the building was sold off as individual homes.
151 of those early buyers have since resold in a measurable arm’s-length transaction. The median outcome was +292%. Even so, 41 of them — 27.2% — sold for less than they paid, which is a useful corrective to the idea that a forty-year hold guarantees anything. Timing the exit still mattered.
The strongest single outcome in the record: a home bought for $73,500 in August 1983 and sold for $1,100,000 in March 2025 — up 1,397% across forty-one years. Set against inflation and forty-one years of carrying costs that is less dramatic than it looks, but it is a real transaction on a real folio.
Across the whole record, the county shows 657 resales, of which 108 — 16.4% — lost money, at a median gain of 44.9% over a median hold of 6.2 years. That is a comfortably better-than-average ownership record for the buildings measured on this site.
The four-year trend, and how far I will go with it
Qualified sales from the Miami-Dade County Property Appraiser record, pulled 17 August 2026 — arm’s-length transactions only.
| Year | Qualified sales | Median price | Median $/sq ft |
|---|---|---|---|
| 2023 | 17 | $560,000 | $624 |
| 2024 | 10 | $590,000 | $679 |
| 2025 | 10 | $647,500 | $691 |
| 2026 to date | 2 | $725,000 | $627 |
Through the last complete year that is $624 to $691, up 10.7% — and unlike several buildings on this site, it is not obviously a size illusion. The median home sold was 897 square feet in 2023, in 2024 and in 2025. The mix did not shift, so the per-foot rise is not simply smaller homes trading.
So I can rule out the usual explanation. What I cannot do is confirm the trend on identical homes, and I want to be straight about why. Restricted to the 897 square foot floorplate, the series reads $624, $602, $641 — on 9, 6 and 4 sales. That is up, then down, then up, on single-digit samples. It neither confirms nor contradicts the 10.7%; it is simply too thin to rule either way.
Where that leaves me: the rise is probably real, because the mix genuinely did not move and the whole-building figure went up three years running. But I hold it more loosely than I would in a building trading eighty times a year, and anyone pricing off it should know it rests on 17, 10 and 10 sales rather than hundreds.
Where the evidence thins out
Three qualifications.
2026 rests on 2 sales. Two. The $725,000 median price and the $627 per-foot figure in that row are the arithmetic of two transactions, and the per-foot figure falls while the price figure rises purely because both homes were larger than the building median. Draw nothing from the 2026 row. It is shown because suppressing it would be worse, not because it means anything.
Sales volume here is modest and falling. 17 qualified sales in 2023, 10 in 2024, 10 in 2025. Turnover works out at about one home in 23 per year. That is normal for a small, largely owner-occupied building, but it means fewer comparables than the raw 878-sale record might suggest.
Age, storeys, amenities and monthly costs are not in this record and are not stated here. The Property Appraiser knows what each home is, what it is worth and what it sold for. It does not know what the association charges, and given the assessment spread described above, the carrying cost here deserves your own diligence rather than my estimate.
Who this building suits
It suits a buyer who wants a one-bedroom on Belle Isle and cares more about a stable ownership record than a growth story. A four-year median of $655 per square foot, in a band from $492 to $803, at a median price of $576,300, on a building where only 16.4% of 657 resales lost money, is a solid rather than exciting proposition — and solid is what the record actually supports.
It suits someone who intends to stay. The assessment structure rewards it directly: the 53 homes here that have not traded since before 2005 are carrying assessments 89% below what a 2021 buyer carries. That advantage accrues to whoever holds, and it is lost the moment the home changes hands.
It suits a short-hold investor poorly. Turnover of one home in 23 a year means you are not exiting quickly, the assessment resets against you on the way in, and the four-year trend — while probably positive — rests on too few sales to underwrite a rapid flip.
If you are selling here, your strongest argument is the 102 identical 897 square foot homes: find the most recent one that traded and price against it directly. Your weakest argument is the 878-sale record, which sounds impressive but mostly describes the 1980s and 1990s.
Belle Plaza — Frequently Asked Questions
Why will my property taxes be higher than the current owner’s?
Because Florida caps assessment increases while an owner stays put, and the assessment resets to market when the home sells. In this building the effect is measurable: the 53 homes last sold before 2005 are assessed at $269 per square foot, while the 75 bought since 2021 are assessed at $507 — 89% higher for homes in the same building. Budget from the reset value, not from the seller’s current bill.
Are prices rising at Belle Plaza?
Probably, and I can say more than usual about why. Median price per square foot went $624 in 2023 to $691 in 2025, up 10.7% — and the median home sold was 897 square feet in all three years, so this is not the size illusion that flatters several other buildings. What I cannot do is confirm it on the 897 sq ft floorplate alone, where the series rests on 9, 6 and 4 sales and shows no clean direction.
How many units are in Belle Plaza?
The county records 223 folios at 20 Island Avenue: 222 residential homes and one reference folio. There are no commercial units, no deeded parking and no storage folios. The mix is 129 one-bedrooms, 70 two-bedrooms, 22 studios and one three-bedroom.
How large are the homes?
Heated area runs from 592 to 1,964 square feet with a median of 897. That median is a floorplate rather than an average: 102 homes — 46% of the building — are exactly 897 square feet.
How far back does the sales record go?
To 1980. The county holds 878 qualified sales here, 131 of them in 1980–83 at a median of $91,400, which is the conversion era. It is one of the longer continuous records among the buildings measured for this site.
Did long-term owners here make money?
Mostly, and substantially. Of the 1980–83 buyers, 151 have resold and the median outcome was +292%. But 41 of them — 27.2% — still sold for less than they paid, so a long hold did not guarantee a gain. The strongest single result was $73,500 in 1983 to $1,100,000 in 2025, up 1,397%.
How easy is it to sell at Belle Plaza?
Slowly but predictably. Turnover runs at about one home in 23 per year — 39 qualified sales in four years against 222 homes. The compensation is comparability: with 102 identical 897 square foot homes, there is usually a genuinely matched recent sale to price against.
Sources and further reading
Interested in selling at Belle Plaza in Miami Beach?
Learn more about selling condo at Belle Plaza with Josh Stein.
Thinking about Belle Plaza?
I have sold South Florida property since 2002, more than $1 billion of it. Ask me for the recorded declaration, what has genuinely closed, or a straight answer on whether this building fits what you are after.
Josh Stein · Florida real estate sales associate, license SL3057661 · (305) 695-8257 · hello@joshsteinrealtor.comRelated coverage
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