Is the tenant’s pro-rata share in the signed lease still the right number?
Not always, and the gap can be big. In one lease I pulled apart recently, the signed document put the tenant’s share at 15.16%. A later amendment — sitting in the public record, filed months after the original lease — moved it to 58.83%.
Every escalation number built off that lease alone was wrong by close to four times, and wrong in the landlord’s favor to lose money, not gain it. If your reconciliation starts with the PDF sitting in the tenant’s folder and nobody has checked what got signed after it, this is the first thing worth verifying.
Where a $174,680 mistake was hiding
This particular tenant is a public company, which means the lease and every amendment are filed with the SEC. That’s the exception, not the rule — most landlords are working with private tenants and no public trail, so the same gap is usually invisible unless someone asks the right question.
The building is an office property in Pittsburgh, leased under the name “Liberty East.” The original lease, signed in November 2021, set the tenant’s proportionate share and gave the space one base year. A First Amendment, signed in February 2024, changed three things that nobody would catch by rereading the original lease alone:
- It added four floors and a fitness center to the premises, bringing the total from 38,258 to 148,266 rentable square feet.
- It pushed the expiration date out to April 30, 2036.
- It reset the tenant’s percentage for the combined space, effective August 1, 2025.
A Second Amendment, signed the same month, adjusted the terms further, including giving the expansion space its own base year separate from the original premises.
| Billed at the original 15.16% share | $60,640 |
|---|---|
| Billed at the amended 58.83% share | $235,320 |
| Unbilled gap | $174,680 |
That’s $174,680 in one year, for one tenant, sitting unbilled because the reconciliation was built on a document that stopped being the whole deal a year and a half before the statement went out.
Four instruments, four dates
| Date | Instrument | What it changed | Where it lives |
|---|---|---|---|
| Nov 16, 2021 | Original Lease | Set the tenant’s share, one base year, 38,258 sq ft | SEC EDGAR |
| Jun 23, 2022 | Commencement Date Agreement | Fixed the actual commencement and expiration dates | SEC EDGAR |
| Feb 28, 2024 | First Amendment | Added 110,008 sq ft across four floors plus a fitness center, extended the term to 4/30/2036 | SEC EDGAR |
| Feb 2024 | Second Amendment | Reset the combined share, gave the expansion space its own base year | SEC EDGAR |
One lease and two amendments, and between them, four separate changes that all feed into the CAM math. The amendments also left something most reconciliation spreadsheets aren’t built to handle: one combined percentage, but two different base years for two different chunks of the same premises.
Nothing in the documents spells out how to split the number between them. Someone has to work that out, and get it right, or the base year calculation is wrong for part of the space no matter which way they guess.
What to check in your own file before you trust the number
- Anything signed after the lease that touches premises, square footage, or “Tenant’s Share” — amendments, addenda, letter agreements.
- Commencement Date Agreements. They often lock in the final square footage that the original lease only estimated.
- Side letters, especially ones tied to an expansion or a give-back of space.
- Estoppel certificates. Tenants write out their own understanding of the share there, which is worth a look even when it isn’t binding by itself.
- The difference between “no amendments exist” and “no amendments were given to me.” From outside the deal, only the second one is ever provable.
That last line does more work than it looks like. A reconciliation can come back clean simply because a folder with nothing extra in it got read as a lease nobody ever touched. Most of the time it just means nobody asked.
Two base years for one premises is the second thing an amendment leaves behind. The first is the cap, and reading its sentence as the wrong mechanic costs more than the gap people worry about: cumulative vs. compounding CAM cap, in dollars
Send me the lease and whatever came after it
I’ll return a recovery profile with every field quoted to the section it came from, plus a list of what the lease itself references but your folder doesn’t contain.
Send the leaseNo charge, 48 hours. Redact names and rent if you’d rather — I only need the recoverable-expense sections.
Sources
Lease, Commencement Date Agreement and both amendments referenced above are public filings by Duolingo, Inc. with the U.S. Securities and Exchange Commission (CIK 0001562088), linked in the table.