Penthouse
For Sale
$899,000
90 William Street 4G, New York City, NY 10038
Full-service penthouse condominium with Sky Terrace, 24-hour doorman/concierge, live-in superintendent, and onsite fitness and laundry.
Property Size1,080 SF
Price / SF$832.41
Days on Market252
Property Features for 90 William Street 4G
General Information
Standard status
Active
Size
1,080 SF
Property subtype
Apartment
Additional Details
Public Transit
Yes
Multifamily Units
1
Taxes and HOA fees
Annual Taxes
$18,360
Amenities
24-hour doorman/concierge
live-in superintendent
Sky Terrace
Sky Lounge
fitness center
billiards room
wet bar
fireplace
entertainment center
central laundry facilities
private storage
Building Details
Building Size
1,080 SF
Year Built
1967
Listing Agency:
Keller Williams NYC
(212) 301-1140
Listed By:
Nicole Gary · License #3525432
(212) 301-1140
Source:
Tricialee
Added: Dec 1, 2025
Changed: Aug 8
Last Checked: Aug 10 at 10:07AM
Displayed information is deemed reliable but is not guaranteed and should be independently verified. All listing content including descriptions, pricing, images are the copyrighted material of Keller Williams NYC
Investment Insights
Based on property information with market context.
Set on the building’s penthouse level, this 1,080 sq. ft. full-service condominium offers a bright, open-concept layout with oversized windows and rich oak hardwood floors. The versatile plan is convertible to two bedrooms and includes an open kitchen with a central island, white lacquer cabinetry, and stainless steel appliances. A second full bathroom with a glass-enclosed shower is located off the main hall for convenient access to both the main living area and the second sleeping area. The primary suite accommodates a king bed setup and features generous closet space, with an en-suite bath offering a deep soaking tub and a double sink vanity. A flexible enclosed alcove with sleek sliding panel doors can serve as a second sleeping area, guest space, or a remote office.
Residents enjoy 24-hour doorman/concierge service and a live-in superintendent, along with a Sky Terrace featuring a wet bar, outdoor fireplace, and Viking grilling station. The Sky Lounge provides an indoor entertainment space with an entertainment center, billiards room, wet bar, and fireplace. A wellness center includes access to a modern fitness center with Life Fitness machines. Central laundry facilities and private storage are also available.
Built in 1967, the property is minutes from Stone Street, the South Street Seaport, and the World Trade Center, with transportation access via Fulton Street Station serving 12 major subway lines.
Residents enjoy 24-hour doorman/concierge service and a live-in superintendent, along with a Sky Terrace featuring a wet bar, outdoor fireplace, and Viking grilling station. The Sky Lounge provides an indoor entertainment space with an entertainment center, billiards room, wet bar, and fireplace. A wellness center includes access to a modern fitness center with Life Fitness machines. Central laundry facilities and private storage are also available.
Built in 1967, the property is minutes from Stone Street, the South Street Seaport, and the World Trade Center, with transportation access via Fulton Street Station serving 12 major subway lines.
Key Highlights
- Penthouse‑level full‑service condominium residence
- Sky Terrace with wet bar, outdoor fireplace, and Viking grilling station
- 24‑hour doorman/concierge and live‑in superintendent
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
$33,790
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
3.76%
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%
$675,800
$675.8K
Cap Rate 7%
$482,714
$482.7K
Cap Rate 9%
$375,444
$375.4K
Market Conditions
NOI Build-Up for 1,080 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
$64.7K $59.88/SF
− Vacancy
−$3.2K −$2.99/SF
EGI
$61.4K $56.89/SF
− OpEx
−$27.6K −$25.60/SF
NOI
$33.8K $31.29/SF
Area
New York, NY
Vacancy
5.00%
Lease Rate
$59.88 /SF/Yr
Expense Ratio
45.00%
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%
$675,800
Cap Rate 7%
$482,714
Cap Rate 9%
$375,444
Alternative Uses
Best Use
Apartment 5plus
$482.7K
$422.4K – $563.2K
NOI $33,790 @ 7.0% cap · market cap 3.76%
Second Best
—
—
no second resolved use
Theoretical Best
Specialty Retail
$2.69M
$2.35M – $3.14M
NOI $188,179 @ 7.0% cap · market cap 20.93%
Zoning and permitted uses should be independently verified with authorities.
Property Analytics
Property Profile
Current Use
Lease Details
1
Residential units
Location Intelligence
Trade Area within ½ mile
33,222
Businesses Nearby
Explore this area
Business Placement
Demographics for 10038, NY
25,332
Population
12,624
Households
2
Avg Household Size
33
Median Age
62%
College-Educated
83%
High-School Grad
0.3 sq mi
ZIP Area
84,440
Density / Sq Mi
$115,121
Median Household Income
$87,698
Median Earnings
$3,140
Median Rent
$865,700
Median Home Value
Questions? Ask Rey
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Frequently Asked Questions
What type of property is this?
Residential income property - Full-service penthouse condominium with Sky Terrace, 24-hour doorman/concierge, live-in superintendent, and onsite fitness and laundry.
Where is this residential income property located?
The property is located at 90 William Street 4G New York City, NY.
What is the asking price?
The asking price for this property is $899,000.
What are key features of this property?
This property features: Penthouse‑level full‑service condominium residence; Sky Terrace with wet bar, outdoor fireplace, and Viking grilling station; 24‑hour doorman/concierge and live‑in superintendent
