Six-Over-Six Duplex with Central
For Sale
$1,150,000
Pending
666 Armstrong Avenue, Staten Island, NY 10308
MULTI_FAMILY - Colonial - Staten Island, NY
Property Size2,680 SF
Lot Size0.13 Acres
Days on Market55
Property Features for 666 Armstrong Avenue
General Information
Property type
Residential Multi Family
Property subtype
Duplex
Zoning
R3-1
Bedrooms
6
Bathrooms
4
Full bathrooms
2
Half bathrooms
3
Rooms
Bedroom 2, Bedroom 3, Bathroom 2, Bathroom 3, Bedroom 4, Bathroom 4, Bedroom 6, Bedroom 1, Bathroom 5, Bedroom 5, Bathroom 1
Parking features
On Street, Driveway
Patio and Porch features
Deck, Patio
Interior features
Walk-In Closet(s), Ceiling Fan(s)
Basement
Partially Finished, Full
Lot features
Front Yard, Back Yard
Subdivision
Great Kills
Standard status
Pending
APN
5054830051
Size
2,680 SF
Lot size
0.13 Acres
Taxes and HOA fees
Tax Annual Amount
8233
Utilities
Sewer type
Public Sewer
Heating system
Natural Gas, Forced Air
Cooling system
Central Air
Building Details
Year built
1970
Floors in Building
2
Number of units
2
Building materials
Brick, Vinyl Siding
Architectural style
Colonial
Listing Agency:
Keller Williams Realty Staten Island
(718) 766-7159
Listed By:
John E Martelotti · License #40MA0954369
(917) 217-0599
Added: Jul 1
Changed: Aug 3
Last Checked: Aug 24 at 7:06PM
MLS# 2603723
Copyright © 2026 Staten Island Board of Realtors. All rights reserved. All information provided by the listing agent/broker is deemed reliable but is not guaranteed and should be independently verified.
Investment Insights
Based on property information with market context.
Welcome to 666 Armstrong Avenue, a well-maintained two-family duplex in Great Kills. Built in 1970 with a classic Colonial style, the property offers a six-over-six layout with both the first- and second-floor units featuring six nicely proportioned rooms. Each unit includes a formal living room, formal dining area, eat-in kitchen, full bathroom, a primary bedroom with a private half bathroom, and two additional bedrooms with ample closet space. Hardwood floors run throughout, with ceiling fans and walk-in closet(s) included. The home features brick construction with vinyl siding, forced air heating with natural gas, central air conditioning, and a public sewer connection.
Set on an extra-deep lot with approximately 0.1337 acres and 2,680 SF, the property includes a large private driveway and outdoor space with a patio and deck. A full basement provides storage and laundry access, plus a half bathroom and plumbing set up for an additional kitchen.
Recent improvements include a new roof in 2023. Zoning is R3-1.
Set on an extra-deep lot with approximately 0.1337 acres and 2,680 SF, the property includes a large private driveway and outdoor space with a patio and deck. A full basement provides storage and laundry access, plus a half bathroom and plumbing set up for an additional kitchen.
Recent improvements include a new roof in 2023. Zoning is R3-1.
Key Highlights
- Six‑over‑six two‑family layout with formal living, formal dining, and eat‑in kitchens
- Central air and forced‑air natural gas heating
- Brick and vinyl siding with hardwood floors throughout
Financial Insights
Estimated NOI and Cap Rate
NOI = area × lease_rate × (100 − vacancy) / 100 × (1 − expense_ratio). Net Operating Income — what the owner takes home each year before mortgage payments and income tax. Effective rent (asking rent minus vacancy losses) minus operating costs (taxes, insurance, maintenance, management).
NOI / Yr
$66,647
Cap rate = NOI / list price × 100. Capitalization rate — annual return on a fully cash purchase, before financing. NOI divided by price. Higher means more income per dollar invested, but usually also more risk or older condition. 5–8% is typical for stabilized commercial property; double digits often signal distressed deals.
Cap Rate
5.80%
Suggested Prices Based on Cap Rates
Cap rates vary significantly by property type, market, and asset quality.
Typical U.S. stable-market ranges:
Multifamily — 4.5% to 6.5% (Class A in primary markets often sub-5%; Class C in secondary markets 6%+)
Industrial / Logistics — 5.0% to 7.0% (compressed heavily in recent years due to e-commerce demand)
Office — 6.5% to 9%+ (wide spread post-2020; CBD Class A vs. suburban Class B varies dramatically)
Retail — 5.5% to 8.5% (grocery-anchored on the low end, unanchored strip centers higher)
Hospitality / Hotels — 7.5% to 10%+ (higher due to operational risk)
Self-Storage — 5.5% to 7.5%
Medical Office — 6.0% to 7.5%
Net Lease (single tenant, credit) — 5.0% to 7.0% depending on tenant credit and lease term
Rules of thumb:
Primary markets (NYC, SF, LA, Boston, DC) trade at lower cap rates than secondary/tertiary markets, often by 100–200 bps (bps, aka basis points; 1 bp = 0.01%).
Class A assets trade ~50–150 bps tighter than Class B, and Class B tighter than Class C.
Cap rates move inversely with price — a lower cap rate means a higher price for the same NOI.
Spread to the 10-year Treasury is a common benchmark; historically 200–400 bps over the 10-year.
Cap Rate 5%
$1,332,940
$1.3M
Cap Rate 7%
$952,100
$952.1K
Cap Rate 9%
$740,522
$740.5K
Market Conditions
NOI Build-Up for 2,680 SF
Vacancy — income lost from leasable area expected to sit empty during the year, subtracted from gross rent.
EGI (Effective Gross Income) — gross rent minus vacancy losses, the realistic income before paying operating costs.
OpEx (Operating Expenses) — recurring costs to operate the property (property tax, insurance, utilities, maintenance, management); excludes financing and capital improvements.
NOI (Net Operating Income) — income a property generates after operating costs but before financing and taxes.
Gross rent
$99.7K $37.20/SF
− Vacancy
−$4.5K −$1.67/SF
EGI
$95.2K $35.53/SF
− OpEx
−$28.6K −$10.66/SF
NOI
$66.6K $24.87/SF
Area
Staten Island, NY
Vacancy
4.50%
Lease Rate
$37.20 /SF/Yr
Expense Ratio
30.00%
Simulate Cap Rate and NOI
Suggested Prices Based on Cap Rates
Cap rates vary significantly by property type, market, and asset quality.
Typical U.S. stable-market ranges:
Multifamily — 4.5% to 6.5% (Class A in primary markets often sub-5%; Class C in secondary markets 6%+)
Industrial / Logistics — 5.0% to 7.0% (compressed heavily in recent years due to e-commerce demand)
Office — 6.5% to 9%+ (wide spread post-2020; CBD Class A vs. suburban Class B varies dramatically)
Retail — 5.5% to 8.5% (grocery-anchored on the low end, unanchored strip centers higher)
Hospitality / Hotels — 7.5% to 10%+ (higher due to operational risk)
Self-Storage — 5.5% to 7.5%
Medical Office — 6.0% to 7.5%
Net Lease (single tenant, credit) — 5.0% to 7.0% depending on tenant credit and lease term
Rules of thumb:
Primary markets (NYC, SF, LA, Boston, DC) trade at lower cap rates than secondary/tertiary markets, often by 100–200 bps (bps, aka basis points; 1 bp = 0.01%).
Class A assets trade ~50–150 bps tighter than Class B, and Class B tighter than Class C.
Cap rates move inversely with price — a lower cap rate means a higher price for the same NOI.
Spread to the 10-year Treasury is a common benchmark; historically 200–400 bps over the 10-year.
Cap Rate 5%
$1,332,940
Cap Rate 7%
$952,100
Cap Rate 9%
$740,522
Alternative Uses
Best Use
Multifamily LT 5
$952.1K
$833.1K – $1.11M
NOI $66,647 @ 7.0% cap · market cap 5.80%
Second Best
Apartment 5plus
$849.0K
$742.9K – $990.5K
NOI $59,432 @ 7.0% cap · market cap 5.17%
Theoretical Best
Office A
$1.28M
$1.12M – $1.49M
NOI $89,513 @ 7.0% cap · market cap 7.78%
Zoning and permitted uses should be independently verified with authorities.
Property Analytics
Property Profile
Current Use
Lease Details
Multi-tenant
Tenancy
Location Intelligence
Trade Area within ½ mile
1,069
Businesses Nearby
Explore this area
Business Placement
Demographics for 10308, NY
28,198
Population
11,093
Households
2.5
Avg Household Size
44
Median Age
40%
College-Educated
94%
High-School Grad
2.2 sq mi
ZIP Area
12,817
Density / Sq Mi
$122,654
Median Household Income
$67,149
Median Earnings
$1,729
Median Rent
$648,800
Median Home Value
Market
Vacancy Rate% for Multifamily in Northeast region
Questions? Ask Rey
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Frequently Asked Questions
What type of property is this?
Duplex - Two-family duplex with six-over-six layout, central air, hardwood floors, and private driveway with deck and patio.
Where is this duplex located?
The property is located at 666 Armstrong Avenue Staten Island, NY.
What is the asking price?
The asking price for this property is $1,150,000.
What are key features of this property?
This property features: Six‑over‑six two‑family layout with formal living, formal dining, and eat‑in kitchens; Central air and forced‑air natural gas heating; Brick and vinyl siding with hardwood floors throughout
