861 Harbor Dr
Key Biscayne, FL 33149 · single_family · Pending — under contract · 135 days on market
Asking price$9,500,000
5 beds 4 baths 3,405 sqft
Suggested offer$4,871,690$4,628,311 above the est. market value of $4,871,690.
View on Realtor.com →Listed by Brigitte De Langeron · DLS International Realty
Typesingle_family
Built1963
Price / sqft$2790
Est. value (own analysis)$4,871,690
Rent estimate (own analysis)$27,500/mo
HOANone
1 / 36
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Statusfor_sale
Listed date2026-04-20
Removed date—
MLSMiamiMLS #A12004666
Coordinates25.68508, -80.16922
Address861 Harbor Dr
CityKey Biscayne
StateFL
Zip33149
Listing ID5056015027
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 | $9,500,000 |
| Down payment (20.0%) | $1,900,000 |
| Loan amount | $7,600,000 |
| Closing costs (5.0%) | $475,000 |
| Total cash to close | $2,375,000 |
| Income | |
| Rent (comp-derived) | $27,500$330,000 |
| Vacancy loss (8.0%) | |
| Effective gross income | $25,300$303,600 |
| Operating expenses | |
| Property tax (placeholder 1.9% of price) | $15,042$180,500 |
| Insurance (placeholder 0.8% of price) | $6,333$76,000 |
| HOA dues | $0$0 |
| Management (0.0% of EGI) | $0$0 |
| Maintenance (5.0% of GSR) | $1,375$16,500 |
| Total operating expenses | $22,750$273,000 |
| 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) | $1,375$16,500 |
| 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.
| Address | Type | Beds | Baths | Sqft | Asking rent | Listed | Days on market |
|---|---|---|---|---|---|---|---|
| single_family | 5 | 6 | 3,650 | $28,500 | 2026-05-19 | — | |
| single_family | 5 | 6 | 3,495 | $20,000 | 2026-06-10 | — | |
| single_family | 5 | 6 | 3,661 | $55,000 | 2026-07-20 | — | |
| single_family | 5 | 5 | 3,202 | $40,000 | 2026-03-28 | — | |
| single_family | 5 | 6 | 3,633 | $21,500 | 2026-05-21 | — | |
| single_family | 5 | 5 | 3,149 | $22,000 | 2026-07-01 | — | |
| single_family | 5 | 7 | 3,475 | $27,500 | 2026-05-21 | — |
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 |
|---|---|---|---|---|---|---|
| 346 Gulf Rd | single_family | 5 | 6 | 3,285 | $4,700,000 | 2026-07-27 |
| 677 Hampton Ln | single_family | 5 | 4 | 2,429 | $3,125,000 | 2026-03-09 |
| 670 Allendale Rd | single_family | 5 | 5 | 2,320 | $3,475,000 | 2026-01-27 |
| 261 Greenwood Dr | single_family | 5 | 6 | 3,525 | $6,275,000 | 2025-12-11 |
| 201 Buttonwood Dr | single_family | 5 | 5 | 3,791 | $5,265,000 | 2025-12-09 |
| 100 Hampton Ln | single_family | 5 | 6 | 3,584 | $6,200,000 | 2025-12-04 |
| 220 Cypress Dr | single_family | 5 | 6 | 4,089 | $4,600,000 | 2025-10-10 |
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 |
|---|---|---|---|---|---|---|
| 485 W Matheson Dr | single_family | 5 | 9 | 11,528 | $237,000,000 | — |
| 501 Bay Ln | single_family | 5 | 5 | 4,759 | $5,990,000 | — |
| 520 S Mashta Dr | single_family | 5 | 4 | 3,085 | $19,900,000 | — |
| 571 Glenridge Rd | single_family | 5 | 7 | 3,768 | $7,490,000 | — |
| 545 Sabal Palm Dr | single_family | 5 | 5 | 4,166 | $7,950,000 | — |
| 24 Grand Bay Estates Cir | single_family | 5 | 6 | 4,220 | $4,950,000 | — |
| 524 Warren Ln | single_family | 5 | 4 | 2,700 | $3,730,000 | — |
| 445 Grand Bay Dr Ph 1A | condos | 5 | 6 | 8,435 | $18,900,000 | — |
10-year hold projection
IRR-6.2%
Equity multiple-0.04x
Total return (10yr)-$1,225,131
| Year | Property value | NOI | Cash flow | Loan balance | Equity |
|---|---|---|---|---|---|
| 1 | $9,785,000 | $30,600 | -$571,976 | $7,517,599 | $2,267,401 |
| 2 | $10,078,550 | $32,883 | -$570,105 | $7,429,540 | $2,649,010 |
| 3 | $10,380,907 | $35,269 | -$568,142 | $7,335,433 | $3,045,474 |
| 4 | $10,692,334 | $37,761 | -$566,084 | $7,234,864 | $3,457,470 |
| 5 | $11,013,104 | $40,364 | -$563,925 | $7,127,389 | $3,885,715 |
| 6 | $11,343,497 | $43,081 | -$561,663 | $7,012,533 | $4,330,964 |
| 7 | $11,683,802 | $45,918 | -$559,293 | $6,889,790 | $4,794,012 |
| 8 | $12,034,316 | $48,879 | -$556,811 | $6,758,618 | $5,275,697 |
| 9 | $12,395,345 | $51,967 | -$554,212 | $6,618,439 | $5,776,906 |
| 10 | $12,767,206 | $55,190 | -$551,492 | $6,468,633 | $6,298,572 |
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.