10WEST1 PROPERTY COMPANY LLC
4 office properties in Washington, DC recorded to 4 owner entities mailing to 68 S SERVICE RD STE 120, MELVILLE, NY. shared mailing address
At a glance
10WEST1 PROPERTY COMPANY LLC is recorded as the owner of 4 office properties (4 parcels) in Washington, DC, totalling 882.9K sq ft of building area with $235.5M of assessed value. The holdings sit in 4 owner entities that share one tax-bill mailing address in MELVILLE, NY — evidence of common ownership, not proof of it.
County assessment roll
Properties
| Building | Submarket | Sq ft | Assessed | Last sold | Tenants |
|---|---|---|---|---|---|
| 1401 H ST NW | Washington | 480.1K | $147.2M | $118,086,001 · Mar 2025 | 3 |
| 17420 PARK ROW DR 581 | Houston | 207.4K | $24.2M | — | 0 |
| 1899 PENNSYLVANIA AVE NW | Washington | 195.3K | $64.1M | $92,196,364 · Dec 2020 | 3 |
| 911 JOHN ST | Columbus | — | — | $118,000,000 · Nov 2022 | 0 |
Names on the deeds
Owner entities at this address
- 1401 H DC PROPERTY COMPANY LLC
- 10WEST1 PROPERTY COMPANY LLC
- 1899 PENN PROPERTY LLC
- MK 2 PROPERTY COMPANY LLC
How this group was built. These entities share a mailing address but not a name root. That often means one sponsor, and can also mean a shared law firm, accountant or tax servicer.The county records an owner and a mailing address for every parcel; this page collects the office parcels whose owners mail to the same address, and counts buildings rather than parcels using the county's own condo-to-building link. Lease terms, rents and the identity of a manager acting for the owner are not public records and are not shown.
Where are 10WEST1 PROPERTY COMPANY LLC's office buildings?
The 4 properties are spread across 3 cities, led by Washington (2), Houston (1), Columbus (1).
The largest is 1401 H ST NW in Washington at 480.1K sq ft.
Recorded build years run from 1925 to 1998.
How large is this portfolio within Washington's office market?
Its 882.9K sq ft is 0.42% of the 212.1M sq ft of office building area on the Washington, DC roll.
Its $235.5M of assessed value is 0.30% of the metro's office total.
It holds 4 of the metro's 1,761 office buildings.
3 of its parcels carry a recorded sale price; the most recent was 1401 H ST NW in Mar 2025 for $118,086,001.
Frequently asked questions
How many office buildings does 10WEST1 PROPERTY COMPANY LLC own in Washington?
4 office properties (4 parcels) on the Washington, DC roll, counted by building rather than by condo parcel.
What is 10WEST1 PROPERTY COMPANY LLC's largest office building?
1401 H ST NW, Washington — 480.1K sq ft, assessed at $147.2M.
What are 10WEST1 PROPERTY COMPANY LLC's office properties worth?
Their combined assessed value on the current Washington, DC roll is $235,451,137. Assessed values are taxable-roll figures, not market prices.
Are these properties owned by one company?
These entities share a mailing address but not a name root. That often means one sponsor, and can also mean a shared law firm, accountant or tax servicer. 4 owner entities share the mailing address. It is evidence of common ownership, not proof of it.
When did one of 10WEST1 PROPERTY COMPANY LLC's Washington office properties last change hands?
The most recent recorded transfer among these parcels is 1401 H ST NW, Mar 2025, for $118,086,001.
Related
Everything here comes from public records, and public records go stale. If you know better, say so.
Data provenance — public records only
- Washington, DC — Integrated Tax System public extract (owner names, mailing addresses, assessments), CAMA commercial and daily sales tables, Basic Business Licenses (suite-level premises; the universal catch-all licence was repealed Oct 2025, thinning the roll thereafter), and DOEE energy benchmarking.
Every fact on this page is drawn from the government records above — no listing sites, no scraped platforms, no third-party images. Facts from public records are uncopyrightable; each tenancy row carries its source and match confidence. Records can lag reality — a business-tax receipt or registration at an address is evidence of occupancy, not a lease confirmation.
Dataset updated . Derived from public data sources.
About this data
Source: Integrated Tax System public extract (Washington, DC), as published September 21, 2026. See the methodology for how records are matched, cleaned and scored.
Cite as: BuildingCensus, “10WEST1 PROPERTY COMPANY LLC — Washington office property holdings”, https://buildingcensus.com/offices/dc/owners/10west1-property-company-llc-f3e320 (data as of September 21, 2026).