Best Data Centre Construction Companies in the UK: How to Choose the Right Contractor for Your Size of Facility
The best data centre construction company for you depends first on size. A hyperscale campus measured in tens of megawatts needs a mission-critical contractor that builds nothing else, while an enterprise data room, edge facility or server room inside an existing building needs a team that can design, build and commission critical systems in a live building without taking the business offline. Choose the type that matches your facility before you compare firms.
This guide covers the seven criteria that matter, the contractor types compared side by side, and where Craftex fits. Since September 2024 the UK government has treated data centres as Critical National Infrastructure, which has raised the bar on security and resilience for owners and operators of every size.
The 7 criteria for a data centre contractor
1. Resilience designed to a stated standard
Resilience is described in terms of redundancy (N, N+1, 2N) and whether systems can be maintained without shutting down. Many clients describe their target using the Tier classification published by the Uptime Institute or the European standard BS EN 50600. Ask the contractor which standard the design follows, who certifies it if you need certification, and how each single point of failure has been removed.
2. Power, from the grid connection inward
For new facilities, the grid connection often sets the programme. For upgrades, the questions are UPS capacity, generator integration, automatic transfer, dual feeds and how load is shared. Ask who designs the electrical system and who carries the risk if the supply capacity isn't there.
3. Cooling matched to rack density
Air cooling with hot and cold aisle containment suits many enterprise rooms. Higher densities may need in-row or liquid cooling. Ask how the design allows for higher density later without rebuilding the room.
4. Fire protection and security
Gas suppression systems protect equipment without water damage. Access control, CCTV, segregation and audit trails are now standard expectations, particularly for regulated sectors such as finance and healthcare.
5. Working in a live environment
Most enterprise projects happen inside a building that's already running: offices above, existing racks next door, a network that can't go down. The method statement for cutover and migration matters more than the drawings.
6. Commissioning and documentation
Integrated testing of power, cooling, fire and controls together, before handover, is what proves resilience. Ask what commissioning stages are included, who witnesses them, and what documentation you receive for audits and insurers.
7. One accountable party
Data rooms involve building works, electrical, mechanical, fire, security and IT cabling. If each sits with a different firm, faults fall between them. Ask who carries the design and the performance risk for the whole room.
Data centre contractor types compared
| Hyperscale / mission-critical contractor | Specialist M&E or critical-systems contractor | Modular or prefabricated data hall vendor | IT integrator / comms room installer | Design and build fit-out with M&E (Craftex) | |
|---|---|---|---|---|---|
| Typical scale | Large campuses and purpose-built halls | Plant and systems on any scale | Containerised or prefabricated halls | Server rooms, cabinets, cabling | Enterprise data rooms, edge and server rooms in existing buildings |
| Building works | Yes, at scale | Usually via a main contractor | Foundations and enabling by others | No | Yes: strip-out, structure, fit-out |
| Power and cooling design | Yes | Yes | Built into the unit | Limited | Yes, coordinated in-house with the building works |
| Live building working | Usually greenfield or dedicated sites | Yes | Limited | Yes | Yes |
| Single point of accountability | Yes, for large schemes | For M&E only | For the module | For IT only | Yes, for the whole room |
| Best for | Operators building at scale | Upgrades where the building works are minor | Speed on a prepared site | Small IT-led rooms | Businesses adding or upgrading a data facility in their own premises |
| Watch for | Minimum project size | Coordination with other trades | Planning, access and site prep | Building, fire and M&E outside scope | Check our record matches your load and size |
If you are building a large purpose-built data centre or campus, a hyperscale or mission-critical contractor is the right type. Our published projects are in the low hundreds of square metres, inside existing buildings.
What our data centre projects show
- Data centre construction and fit-out, London. After a series of office refurbishments for the same FinTech client, we designed and built a new data centre in an unused basement of their London headquarters: 220 m² in 10 weeks. The brief called for redundant power, advanced cooling and Tier 3 performance standards. Scope included power distribution with UPS and generator integration, hot and cold aisle containment, structured CAT6A and fibre cabling, BMS environmental monitoring, biometric access control, CCTV and FM-200 gas suppression. Critical systems were commissioned over a single weekend to fit the client's network maintenance window.
- Data centre expansion and infrastructure upgrade, Manchester. For a healthcare technology client, we expanded and upgraded an existing facility: 310 m² in 12 weeks, with the aim of doubling rack capacity, introducing new cooling and upgrading the electrical backbone while operations continued. Scope included dual power feeds with automatic transfer switches, redundant UPS, aisle containment, raised floors, an IG-541 gas suppression system and leak, temperature and humidity sensors. The case study records zero downtime during migration and testing.
The team behind the work
- Sviatoslav (Sviat) Jerdetchii, CEO and Founder, mechanical engineering background.
- Joe Crawford, Operations Director: 37 years in construction, on projects of up to £135M in previous roles.
- Martin Hickey, Preconstruction Director: more than 50 years in construction.
- Konstantin Jegorovs, Projects Director: 16 years, Oxford Brookes construction management graduate.
Craftex has been trading since 2016, holds ISO and CHAS accreditation, carries £10M public liability and £10M employer's liability insurance, and delivers around 70% of its labour in-house. Our construction projects run from £100,000 to £10M+.
Where Craftex is not the right fit
- Hyperscale and large colocation builds. Choose a contractor that builds those every year.
- A rack or two in a comms cupboard. An IT integrator will do it faster and for less. Our construction work starts at £100,000.
- Equipment supply only. We design and build the room and its infrastructure; we're not a hardware reseller.
How to brief a data centre contractor
- State the IT load now and in five years, and the target resilience.
- Share the building constraints: floor loading, ceiling heights, risers, plant space, access and the existing electrical supply.
- Set the operational rules: what can't be switched off, maintenance windows, security vetting.
- Ask each bidder for its commissioning plan and handover documentation, not only a price.
- Compare who carries the design and performance risk for the whole room.
See our data centre construction services and data centre fit-out and infrastructure pages, and our article on energy-efficient data centre construction.
