550 Harbor Dr
Key Biscayne, FL 33149 · single_family · For Sale · 295 days on market
Asking price$19,450,000
7 beds 8 baths 6,497 sqft
Suggested offer$14,075,968$5,374,032 above the est. market value of $14,075,968.
View on Realtor.com →Listed by William Earle · Three Bridges Realty, Llc
Typesingle_family
Built2003
Price / sqft$2994
Est. value (own analysis)$14,075,968
Rent estimate (Zillow ZIP avg)$7,910/mo
HOANone
1 / 67
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Statusfor_sale
Listed date2025-11-11
Removed date—
MLSMiamiMLS #A11912105
Coordinates25.69088, -80.17284
Address550 Harbor Dr
CityKey Biscayne
StateFL
Zip33149
Listing ID6228600382
Sourceus-real-estate-listings, cached 2026-08-31
ZIP market snapshot (33149)
Typical home value (ZHVI)$1,692,135
Typical rent (ZORI)$7,910/mo
Zillow Research's ZHVI (home value index) and ZORI (rent index) for this ZIP, as of 2026-07 — free published data, refreshed monthly, no RentCast quota spent. "Typical value/rent" is a smoothed index, not a literal median of active listings.
Underwriting (buy-and-hold, default assumptions)
| Acquisition (one-time, not monthly/yearly) | |
| Purchase price | $19,450,000 |
| Down payment (20.0%) | $3,890,000 |
| Loan amount | $15,560,000 |
| Closing costs (5.0%) | $972,500 |
| Total cash to close | $4,862,500 |
| Income | |
| Rent (ZIP avg, ZORI — not bedroom-specific) | $7,910$94,922 |
| Vacancy loss (8.0%) | |
| Effective gross income | $7,277$87,328 |
| Operating expenses | |
| Property tax (placeholder 1.9% of price) | $30,796$369,550 |
| Insurance (placeholder 0.8% of price) | $12,967$155,600 |
| HOA dues | $0$0 |
| Management (0.0% of EGI) | $0$0 |
| Maintenance (5.0% of GSR) | $396$4,746 |
| Total operating expenses | $44,158$529,896 |
| Net operating income (NOI) | |
| Debt service & reserves | |
| Debt service (6.66%, avg 30yr rate as of 2026-08-27, 30yr amortizing) | |
| CapEx reserve (5.0% of GSR) | $396$4,746 |
| Mortgage insurance (PMI) (0.0% of loan, not required — down payment ≥ 20%) | $0$0 |
| Cash flow |
Cap rate
Cash-on-cash
DSCR
Rent-to-price (1% rule)
Gross rent multiplier
Operating expense ratio
Break-even occupancy
Comparables
Same ZIP. Real active rental listings, used to derive the rent estimate above.
No active rental listings cached yet for this bedroom count.
Same ZIP & bedroom count. Closed sales from Realtor.com over the last 12 months, matched to this property's type — real transaction prices, not asking prices. Falls back to Miami-Dade County public records (property appraiser tax roll) when Realtor.com has no sales on file for the area.
| Address | Type | Beds | Baths | Living sqft | Sale price | Sale date |
|---|---|---|---|---|---|---|
| 111 Reef Ln | single_family | 7 | 6 | 5,008 | $10,850,000 | 2026-08-07 |
| 230 Harbor Dr | single_family | 7 | 8 | 6,240 | $17,500,000 | 2026-07-08 |
| 797 Ridgewood Rd | single_family | 7 | 8 | 5,528 | $6,500,000 | 2026-03-31 |
Same ZIP. Other properties currently for sale nearby — asking prices, not closed sale prices. Not a price comp; see Sold comps for actual transaction history.
| Address | Type | Beds | Baths | Sqft | Asking price | Days on market |
|---|---|---|---|---|---|---|
| 425 Harbor Dr | single_family | 7 | 9 | 4,565 | $7,450,000 | — |
10-year hold projection
IRR-12.6%
Equity multiple-1.16x
Total return (10yr)-$7,982,316
| Year | Property value | NOI | Cash flow | Loan balance | Equity |
|---|---|---|---|---|---|
| 1 | $20,033,500 | -$442,568 | -$1,647,227 | $15,391,295 | $4,642,205 |
| 2 | $20,634,505 | -$453,196 | -$1,657,973 | $15,211,005 | $5,423,500 |
| 3 | $21,253,540 | -$464,076 | -$1,668,975 | $15,018,334 | $6,235,206 |
| 4 | $21,891,146 | -$475,215 | -$1,680,239 | $14,812,432 | $7,078,714 |
| 5 | $22,547,881 | -$486,618 | -$1,691,770 | $14,592,391 | $7,955,490 |
| 6 | $23,224,317 | -$498,292 | -$1,703,575 | $14,357,239 | $8,867,078 |
| 7 | $23,921,047 | -$510,243 | -$1,715,660 | $14,105,940 | $9,815,107 |
| 8 | $24,638,678 | -$522,478 | -$1,728,032 | $13,837,383 | $10,801,295 |
| 9 | $25,377,838 | -$535,002 | -$1,740,698 | $13,550,384 | $11,827,455 |
| 10 | $26,139,174 | -$547,824 | -$1,753,665 | $13,243,676 | $12,895,497 |
Assumes 3.0% annual rent growth, 2.5% expense growth, 3.0% appreciation, and a 6.0% selling cost at exit — all placeholder assumptions, not market-derived.