Methodology

Where the data comes from

Rank and revenue come from ENR’s Top 400 Contractors tables in the May 25, 2026 issue: the overall rank, the 2025 revenue, the share of revenue by market sector and the share delivered as construction manager at risk, plus ENR’s Top 20 in the telecommunications sector, which is where ENR counts data centers. Delivery models, self-performed trades, megawatt claims and named clients come from each contractor’s own website, project pages and press releases. Every record lists its sources with the date we accessed them, and every number in the table links to the source it came from.

Who is on the list

A firm is listed when it leads data center construction as general contractor, construction manager, design-builder or EPC contractor, and at least three facts about it can be sourced. Electrical contractors such as Rosendin and M.C. Dean, which publish data center work as a trade partner rather than as prime, are left out, as is MasTec, whose ENR telecom revenue is mainly fiber and wireless. Builders ranked by megawatts delivered and their reference projects are covered by the sister directory datacenterconstructioncompanies.com.

How we verify

Each row shows the date we last checked it. A field stays empty when it was not verified in the sources reviewed. Megawatt claims keep their basis (delivered, delivered or underway, annual, pipeline), so two MW figures are only comparable when their bases match. Reference project capacity and status are separate fields. An award or groundbreaking announcement does not establish completion. ENR ranks firms reporting US and international construction revenue; a blank rank means the cited table does not establish one for that record.

Delivery models and self-perform capabilities can describe a whole company, regional division or named subsidiary. They are not proof that every listed trade is self-performed on every data center. The scope qualifiers stay with the value. We do not infer CM at risk from ordinary construction management, design-build from design support, or own-crew installation from a managed subcontract scope. Contractor type and market regions normalize the roles and locations described in the cited sources.

Second-pass exclusions

ISG’s UK construction companies are excluded: EY’s administrators state that they entered administration on 20 September 2024 and ceased trading (accessed 11 November 2026). Kirby’s data centre page establishes specialist mechanical, electrical and high-voltage work, but not a whole-campus prime contract. Arcadis describes design and project management for KBC’s data centers; that role is outside this directory’s construction-prime scope.

Corrections

Vendors and readers can send corrections to hello@datacentergeneralcontractors.com with a public source. We update the row and its verified date. Featured placement is paid and labelled; it never changes a row’s data or its position in the sorted table.

Reuse

The dataset is free to reuse under CC BY 4.0 with a link to datacentergeneralcontractors.com. Download it as CSV or JSON.