This guide is for the owner of a tower, not the owner of the land under one. It explains what happens between the written answer and the offer, which is the part of a sale most buyers describe least.
The price of a tower is what the tower can carry. Everything else in an offer, the tenants, the ground lease, the paperwork, the place, adjusts that number up or down, but the number starts with the structure. So before we make an offer, a licensed engineer reads the structure. This guide covers who does that, what they read, how the result becomes a price, and why the price on our letter is the price at closing.
Who does the review
We describe our team by what each person is licensed to do, because that is what a seller needs to know. Our about page lists the three disciplines. Two of them are in this guide.
Structural underwriting is done by a licensed Professional Engineer, licensed across the 48 contiguous states, who reviews the structure and loading of every tower before we offer and signs the analysis. That person is on our side of the table, not a consultant hired for the file, and the same engineer reads every tower we look at. The review is step 2 of the five on our selling page, and it usually takes about 14 days.
Site operations is run by a licensed general contractor who makes the diligence visits, does the post-close work, and keeps the ground-lease relationship. When someone from Trinity River walks your compound, that is who it is, and the engineer reads what they bring back.
No broker's spreadsheet, no desk estimate, and no third party's letter substitutes for either. If a tower is worth an offer, it is worth an engineer's afternoon.
What the engineer reads
Five things, in roughly this order.
The drawings. The fabrication drawings and the foundation drawings, if they exist. They say what the tower was built to be: the sections, the steel, the base, the guy anchors on a guyed tower. A tower without drawings can still be underwritten, but the engineer has to measure what the drawings would have told them, and that takes longer.
The design code. Every tower in the United States is designed and checked against TIA-222, the Telecommunications Industry Association's structural standard for antenna supporting structures, which building codes adopt by reference. The revision a tower was designed under matters, because the wind and ice loads the standard assumes have changed over the years. The current revision, TIA-222-I, took effect at the start of 2024, and a tower that passed under an older revision may have less headroom under it. The engineer checks the tower against the revision in force where it stands.
What is on it today. Every antenna, mount, dish, line, and platform, by height and by tenant. The tenant leases say what each carrier is allowed to install. The site visit says what they actually installed, and the two are not always the same. A carrier that added a mount and two panels without an amendment has added load the lease does not show.
The public records. The FCC antenna structure registration and the FAA determination, for the registered height and the painting and lighting the tower is required to carry. Reading your tower's ASR record before you sell explains what each field says; for the engineer, the question is whether the height on the record is the height on the ground.
The tower itself. The site visit looks at what no document can: the condition of the steel, the foundation, the guy wires and anchors, the grounding, corrosion, missing bolts, a lean. A tower that is sound on paper and rusted at the anchor is priced on the anchor.
From these the engineer produces, or reads, a structural analysis: a calculation of what the tower can carry under its design code and the loads on it, with a stamp on it. If a current stamped analysis already exists, the engineer reads it against the site visit rather than redoing it. If none exists, the engineer builds one.
From capacity to price
The analysis gives a number for headroom: how much more load the tower can take before it reaches its limit under the code. Headroom is the thing a buyer is really buying, because it is what the next tenant pays for.
The second thing the analysis gives is where that headroom sits. A rad center is the height at which a tenant's antennas are mounted. A tower may have capacity in the steel but no open height a carrier would want, because every useful elevation is taken. Or it may have an open rad center at a height a carrier would want and no capacity to put anything on it. Price follows the combination: an open rad center with the capacity behind it is worth underwriting as a future tenant. Either one alone is not.
What a stamped analysis changes is the difference between a guess and a number. "There is room" is a sentence a buyer discounts, because every seller says it. A stamped analysis showing headroom at a specific height is a fact a buyer can underwrite, and the price moves to reflect it. The reverse is also true. If the analysis shows a tower at its limit, the buyer prices the tower on the tenants it has, and no amount of optimism about the next carrier changes that.
This is also why a single-tenant or empty tower can carry a higher multiple of its cash flow than a full one, a point What a cell tower is worth in 2026 makes at length. The buyer is paying for the headroom. The engineer is the one who says whether it is there.
Why the LOI holds
Our letter of intent is set to the engineering. That phrase does a specific job. It means the price on the letter was built from the structural review and the facts you disclosed, after the engineer read the tower, not before. Most of what diligence later confirms, the engineer has already seen. So there is nothing left in the structure to discover, and nothing left in the structure to re-trade on.
The one exception is written into the letter, and it is narrow: something material that was not disclosed. Material means it changes what the tower can carry or what it earns. Undisclosed means we asked and the answer was not there, or was wrong. A guy anchor the drawings show and the site visit cannot find is material and, if we were told the anchors were all in place, undisclosed. A tenant lease amendment that cut the rent and was left out of the rent roll is material and undisclosed. A gate that sticks is neither.
That is the whole list of things that move the price between the letter and closing. A clean tower closes at the number on the letter. From first call to close walks through the steps on either side of it.
What you can do before we look
Three documents shorten the review and usually raise the number.
A stamped structural analysis. If you have one, send it, whatever its date. A current one is best. An older one still tells the engineer what the tower was checked against and when, and it can often be updated rather than rebuilt. If you do not have one and believe the tower has room, commissioning one before you go to market is the single fix most likely to pay for itself, because it turns the room into a number every buyer can read.
The drawings. Fabrication drawings, foundation drawings, and any modification drawings from later work. If the original builder is still in business, they often have them. If a carrier reinforced the tower to add equipment, their engineer had drawings for the work.
Photographs. Recent, from the ground, of the whole structure, the base, the anchors on a guyed tower, the compound, and the access road. Close enough to read the mounts. They let the engineer plan the site visit instead of discovering the tower on arrival.
None of these is required to start. All of them move the engineering review faster, and faster is the difference between a 14-day step and a longer one.
Start with the facts
Send where the tower is, the structure type and height, who is on it, and whether the land is owned or leased. The written answer comes first; if it says go, the engineer's review follows, and the offer is built on what the engineer finds. Submit a site.
Sources
- Trinity River Assets, About: the team by credential and How we buy: the five steps and their typical durations
- Telecommunications Industry Association, ANSI/TIA-222-I, Structural Standard for Antenna Supporting Structures, Antennas and Small Wind Turbine Support Structures (Revision I, 2023) (opens in a new tab) and TIA opens revision period of TIA-222 standard (2022), on the standard's use by the International Building Code (opens in a new tab)
- Trinity River Assets, What a cell tower is worth in 2026
- Trinity River Assets, Reading your tower's ASR record before you sell