CARBON LLC
3 office properties in Washington, DC recorded to 3 owner entities mailing to 1627 K ST NW LOWR LEVEL LOWER LEVEL, WASHINGTON, DC. shared mailing address
At a glance
CARBON LLC is recorded as the owner of 3 office properties (3 parcels) in Washington, DC, totalling 267.2K sq ft of building area with $33.5M of assessed value. The holdings sit in 3 owner entities that share one tax-bill mailing address in WASHINGTON, DC — evidence of common ownership, not proof of it.
County assessment roll
Properties
| Building | Submarket | Sq ft | Assessed | Last sold | Tenants |
|---|---|---|---|---|---|
| 501 SCHOOL ST SW | Washington | 119.7K | $10.3M | $16,557,000 · Jul 2017 | 2 |
| 475 SCHOOL ST SW | Washington | 80.6K | $13.4M | $16,250,000 · Nov 2016 | 3 |
| 1023 15TH ST NW owner on site | Washington | 66.9K | $9.8M | — | 25 |
Names on the deeds
Owner entities at this address
- CARBON LLC
- TELLURIUM LLC
- NEON 23 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. 1of these properties also carry a business-tax receipt in the owner's own name, which is the public record's way of showing an owner-occupier rather than a landlord. Lease terms, rents and the identity of a manager acting for the owner are not public records and are not shown.
Where are CARBON LLC's office buildings?
All 3 properties are in Washington.
The largest is 501 SCHOOL ST SW in Washington at 119.7K sq ft.
Recorded build years run from 1968 to 1988.
How large is this portfolio within Washington's office market?
Its 267.2K sq ft is 0.13% of the 212.1M sq ft of office building area on the Washington, DC roll.
Its $33.5M of assessed value is 0.04% of the metro's office total.
It holds 3 of the metro's 1,761 office buildings.
2 of its parcels carry a recorded sale price; the most recent was 501 SCHOOL ST SW in Jul 2017 for $16,557,000.
1 parcel also carries a business-tax receipt in the owner's own name — an owner-occupier rather than a landlord.
Frequently asked questions
How many office buildings does CARBON LLC own in Washington?
3 office properties (3 parcels) on the Washington, DC roll, counted by building rather than by condo parcel.
What is CARBON LLC's largest office building?
501 SCHOOL ST SW, Washington — 119.7K sq ft, assessed at $10.3M.
What are CARBON LLC's office properties worth?
Their combined assessed value on the current Washington, DC roll is $33,483,370. 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. 3 owner entities share the mailing address. It is evidence of common ownership, not proof of it.
When did one of CARBON LLC's Washington office properties last change hands?
The most recent recorded transfer among these parcels is 501 SCHOOL ST SW, Jul 2017, for $16,557,000.
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 20, 2026. See the methodology for how records are matched, cleaned and scored.
Cite as: BuildingCensus, “CARBON LLC — Washington office property holdings”, https://buildingcensus.com/offices/dc/owners/carbon-llc-f923f6 (data as of September 20, 2026).