Onyx on the Bay

What Is Actually in Onyx on the Bay

Onyx on the Bay’s 117 homes are what the Miami-Dade County Property Appraiser actually shows for 665 NE 25th Street — one folio for every residence in the subdivision, with no separate commercial parcels attached to this declaration. The building leans two-bedroom: 74 of the 117 homes carry two beds, 35 are one-bedroom, seven are three-bedroom, and exactly one is a four-bedroom home.

Unit sizes run from 886 square feet up to 3,359 square feet, with a median of 1,285 square feet — the size the building actually trades on. The four most common floorplates (1,368, 1,508, 942 and 1,285 square feet) account for roughly 60% of all homes here.

The county’s 2026 assessed values run from $197,791 to $2,262,200, with a median of $507,814 across all 117 folios. That’s an assessment, not a sale price, but it’s a useful sanity check against what follows.

I did not find a storey count, architect, construction year or amenity list anywhere in the county record — those live outside the Property Appraiser’s dataset, and I’m not going to invent them. Everything below is built entirely from the 117 folios and their sale histories.

The Price Record at Onyx on the Bay

The four-year record below is built from every qualified, arm’s-length sale on the county’s own flag, grouped span-aware so a home sold together with its deeded parking space counts once — not as a multi-parcel portfolio transfer.

Median price fell from $730,000 in 2023 to $680,000 so far in 2026 — a 6.8% decline. Median price per square foot fell further, from $647 to $509, a 21.3% drop. That gap between the two numbers is worth sitting with: floorplate mix shifted year to year along with price, and I’d trust the per-square-foot figure over the sticker price for that reason.

I want to flag one sale directly rather than let it sit quietly inside that $509 figure. On January 14, 2026, a 1,508-square-foot home sold for $210,000 — $139 a square foot. That’s far outside the building’s own four-year band, which otherwise runs roughly $447 to $928 a square foot. The same unit last sold for $600,000 in September 2021. The county flags the January sale qualified, and I have no basis to call it anything other than arm’s-length, but the price sits so far outside every comparable in the building that I don’t think it belongs in a median without comment. Pull it out and the 2026 figures read: 5 sales, median price $685,000, median $517 a square foot, and the four-year $/sf decline reads 20.1% instead of 21.3%. Either way the direction is the same. The exact magnitude depends on one deed.

With only 23 qualified sales across four years — and just two of them in all of 2025 — I’d rather state plainly that this record supports a soft, declining trend and not much more. The direction reads real to me; I would not defend the precise percentage past what I’ve shown here.

Which Sale Actually Set the Record at Onyx on the Bay?

Ask which sale set Onyx on the Bay’s record and the honest answer depends on what you mean by “record.”

By total dollars, it’s $2,200,000 — a 3,359-square-foot penthouse, unit PHII-01, that closed March 29, 2016. Priced per square foot, that sale works out to $655. It has stood for nearly a decade; no home in the building has sold for more total money since.

But it is not the building’s per-square-foot record. That belongs to a much smaller home: 1,508 square feet, sold March 25, 2026, for $1,400,000 — $928 a square foot, the highest figure in the county record for any qualified sale here, penthouse included. I checked this against multi-folio sales too, in case a combined transaction (a home sold together with a second, adjoining folio) was hiding a bigger number. None comes close — the largest multi-folio sale on record totals $1,200,000 across 1,970 combined square feet, or $609 a square foot.

So the building is carrying two different records at once, set almost a decade apart, on homes less than half the size of each other. That matters if you’re pricing a smaller, updated unit against the building’s history — the $2,200,000 penthouse sale isn’t your comparable unless you own PHII-01 or PHII-02. The more relevant number for most of this building is $928 a square foot, and it’s a March 2026 data point, not a 2016 one.

Who Onyx on the Bay Suits — and Who It Doesn’t

Onyx on the Bay suits a buyer who wants an established Edgewater tower with a real, multi-decade sales history behind it — 117 homes and well over 200 qualified sales since 2007 give you more comparables to underwrite a purchase against than a newer building can offer. It also suits someone comfortable with a thin resale market: on the four-year average, about one home in 20 changes hands here in a given year, so you may be waiting for the right unit rather than choosing from a deep active list.

It suits less well a buyer looking for a building on a clear upward run. The four-year record here points down, not up — median $/sf off 21.3% since 2023 — and given how few sales the recent years actually contain, I wouldn’t describe that trend as anything stronger than probably real, with the exact magnitude uncertain.

For sellers: price against your own floorplate’s recent comparables, not against the building’s headline record. The $2,200,000 penthouse sale from 2016 is real, but it is not your comparable unless you’re selling one of the two penthouse units it belongs to. The building’s more relevant, more recent data point is the $928-a-square-foot sale from March 2026 — on a home a fraction of that size.

Interested in selling at Onyx on the Bay?

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Edgewater Condo & Loft Buildings

Edgewater runs along Biscayne Bay between the Venetian Causeway and the Julia Tuttle. Every building below is covered in this series, with its own county sales record:

• 1800 Biscayne Plaza
• 1800 Club
• Aria on the Bay
• Bay House
• Biscayne Beach
• Blue Condominium
• Cite on the Bay
• City 24
• Edgewater Lofts
• Elysee Miami
• Gallery Art Condominium
• Gran Paraiso
• Icon Bay
• Moon Bay
• New Wave
• One Paraiso
• Opera Tower
• Paraiso Bay
• Paramount Bay
• Platinum Condo
• Quantum on the Bay
• The Crimson
• The Grand Condos Miami
• Uptown Lofts