Every AI data center begins as paperwork — an interconnection study, a substation layout, a water-withdrawal permit, a stamped set of drawings. Jacobs Solutions, a Dallas-based engineering and consulting firm of about 47,000 people, is the only large firm in that business that has told investors how much of the work it now holds.

AI data-center build-out reached 11% of Jacobs' adjusted net revenue — the fee base that remains after subcontractor and equipment costs pass through — in its fiscal third quarter, up roughly a point from the previous three months. Management said the related backlog has doubled and the pipeline tripled, with client visibility stretching from six-to-nine months out to two or three years. Engineering News-Record ranks Jacobs the largest data-center design firm. In the quarter it took a sole-source engineering, procurement and construction-management award from Hut 8 for Beacon Point, a 1GW campus in Texas due for first energization in 2027, following the River Bend campus in Louisiana. Company-wide backlog hit a record $29bn, up 27%, and Jacobs raised full-year adjusted earnings guidance for a third consecutive quarter, to $7.20-7.30 a share.

The shares are worth what they were a year ago.

The fee and the pass-through

Part of the answer is in how the AI money arrives. Jacobs' revenue grew 34.6% to $4.08bn last quarter while gross profit grew 7.3%. Gross margin fell from 24.9% to 19.9%, and net income dropped 26.7%. Construction-management dollars inflate the top line and carry almost no margin with them.

Tetra Tech, a Pasadena consulting firm of about 25,000 people split between US government agencies and commercial water, energy and mining clients, shows the same arithmetic more starkly. Revenue rose 13.5% to $1.31bn in its June quarter while gross profit fell 3.3% to $243.2m, a 323 basis-point margin compression. Across three quarters revenue growth accelerated — 1.1%, then 10.6%, then 13.5% — and gross profit fell in every one. Its data-center practice runs at roughly $60m annualized; its Ukraine reconstruction work for the US Department of State billed $66m in the quarter alone. The federal-cuts story told about Tetra Tech is also backwards: US federal revenue grew 12% while US commercial grew 1%, offshore-wind cancellations offsetting data-center and mining gains. The company raised fiscal 2026 guidance on 30 July to revenue of $4.315-4.365bn and earnings of $1.56-1.59 a share.

The firms that refuse the construction risk

Stantec, an Edmonton-based design and environmental consultancy of about 34,000 people, takes the opposite route: fees for drawings and studies, no construction exposure. Net revenue rose 11.5% to C$1.8bn in the second quarter, of which 3.7% was organic, and adjusted earnings per share rose 18.4% to C$1.61. Adjusted margin reached a record 18.7% for a second quarter. Backlog set a record at C$9.2bn, up 17.5% and 7.0% organically, about thirteen months of work; its US book grew to C$5.5bn from C$4.6bn. Its buildings team was selected to design Meta's $13bn campus in Sturgeon County, Alberta — the largest named AI-campus design mandate any of these firms has disclosed. The soft spot is domestic: US organic growth was flat, as a Navy environmental job and a Western utility project ramped slower than planned.

AECOM, a 51,000-person infrastructure consultancy, demonstrated in one session what construction risk costs a design firm. It booked a $337m pretax charge on a 2018-vintage public-private design-build contract, attributed in analyst notes to the JFK Airport modernization program. June-quarter revenue fell 14.2% to $3.59bn, the company posted a net loss of $86.7m, and adjusted earnings of -$0.50 a share missed a $1.51 consensus. Free-cash-flow guidance was cut to $300m from $400m, with about $500m of cash draining out through the first half of fiscal 2027. Orders said the reverse: record backlog of $27.8bn, up 13%, at a 1.6x quarterly book-to-burn. Management has said it will not bid public-private design-build again, and that construction management is 6-7% of net service revenue.

Demand is not the constraint. Pennsylvania's governor removed data centers from the state's permit fast-track program on 18 August, requiring any project drawing 25MW or more to sign a consent agreement with the environmental regulator — mechanically adding review and interconnection work of exactly the kind these four firms sell.

What the prices say

AECOM sits near 10.5x consensus fiscal 2027 earnings of $6.17, and 10.8x management's own ex-charge figure of $6.00 — against 22-24x forward as recently as May. Stantec is 23.0x trailing, down from 28.95x in early May, roughly 21.5x forward on a like-for-like currency basis, with a 5.7% free-cash-flow yield. Tetra Tech's 23.5x forward sits above its 22.2x trailing, meaning analysts model earnings lower than the past year's. Jacobs is 20.7x forward — the cheapest forward multiple of the three that disclose growing data-center work, and the only one with a quantified AI number behind it.

Over twelve months AECOM fell 47% and Stantec 33%, while Jacobs and Tetra Tech went nowhere. The contractors that build what these firms draw compounded: Comfort Systems rose 140%, Quanta Services 72%, EMCOR 27%. The market has priced the design rung as one class and has not yet separated the firm with the biggest disclosed AI book from the ones describing it in adjectives.

The setup

Where it stands — Jacobs is the only large design firm quantifying AI exposure, at 11% of fee revenue, and carries a lower forward multiple than Tetra Tech's 1.4%. Would confirm — AI data centers exceeding 12% of adjusted net revenue in the October-quarter report with adjusted margin holding. Would invalidate — data-center backlog growth stalling, or fee margin falling further as pass-through revenue keeps climbing. Watch next — Jacobs' fiscal fourth-quarter results in November; Stantec's CEO handover to Susan Reisbord on 1 October. Valuation — Jacobs 20.7x forward against a distorted 52.3x trailing; Tetra Tech 23.5x forward, Stantec 23.0x trailing, AECOM ~10.5x fiscal 2027.