Colocation London
Colocation London
London is Europe’s largest and most competitive colocation market. It is also one of the most constrained — vacancy is at record lows, power connections in established sub-markets are years away for new applicants, and the gap between stated capacity and genuinely deliverable capacity is wider than at any point in the market’s history. For enterprise organisations sourcing colocation in London, knowing which operators have real availability on a credible timeline is the difference between a deployment that completes on schedule and one that doesn’t.
London Colocation in the Current Market
London hosts 135 data centre facilities across 53 operators, representing approximately 2.77 gigawatts of installed capacity — Europe’s largest concentration of colocation infrastructure. Despite this scale, vacancy is projected below six percent by year end, driven by structural demand from AI infrastructure programmes, enterprise digital transformation, and the rapid growth of neocloud providers requiring GPU-ready capacity at short notice.
The colocation market in London operates across two fundamentally different segments. Retail colocation — individual cabinets or small cages in shared facilities — remains accessible, though at premium pricing. Wholesale colocation — dedicated data halls or multi-megawatt power blocks at 1MW and above — is where scarcity is most acute. Operators with genuine wholesale availability on a twelve to eighteen month timeline are a small subset of the total London operator base, and their capacity is not uniformly visible through standard market channels.
Power is the defining constraint. Grid connections at primary substations in West London and Slough now extend beyond seven years for new applicants. This has driven new development to East London, Hertfordshire, and Oxfordshire — markets where power headroom remains and planning appetite is supported. For wholesale colocation buyers, understanding this geographic shift is essential to identifying where capacity can actually be delivered on a business-relevant timeline.
London Colocation at a Glance
135
Active data centre facilities across Greater London
<6%
Projected vacancy rate — a record low
£150–300
Per kW per month — wholesale colocation rate range
7yr+
Grid connection timeline at constrained West London substations
Source: CBRE UK Data Centres Outlook, Armason market intelligence.
London Colocation Options
What is genuinely available and where.
Retail Colocation
Individual cabinets and small cages in shared London facilities. More accessible than wholesale but at significant premium pricing — particularly for high-density deployments where GPU or AI workloads require liquid or hybrid cooling. Several established operators have retail capacity available across London sub-markets with relatively short lead times. Pricing typically ranges from £300 to £2,000 per cabinet per month depending on location, density, and operator.
Wholesale Colocation
Dedicated data halls or multi-megawatt power blocks at 1MW and above. The segment where London scarcity is most acute. Operators with genuine wholesale availability on a twelve to eighteen month timeline are a minority of the total London operator base. Pre-let opportunities — capacity contracted before a facility reaches energisation — represent the most realistic route to new wholesale colocation in the near term for most buyers.
Build-to-Suit
Facilities built to exact specification for a single enterprise buyer, typically in the operator’s existing development pipeline or on land the buyer identifies. Build-to-suit provides the highest degree of customisation but requires the longest lead times — typically three to five years from land identification to energisation in London. Armason works with operators to bring forward build timelines where standard delivery is incompatible with the buyer’s business requirement.
Adjacent Markets
For buyers with geographic flexibility, Hertfordshire, Oxfordshire, and East London offer faster access to new colocation capacity than established West London sub-markets. Latency to central London from these locations is typically under five milliseconds — acceptable for the majority of enterprise workloads. Pricing is materially lower and power headroom is significantly greater. Armason provides clear options across all London-adjacent sub-markets as part of every engagement.
Sourcing Colocation in London
Armason is not a colocation provider, a directory, or a marketplace. We are a neutral intermediary that structures enterprise requirements and matches them to operators with genuine availability — with no commercial relationship with any operator that creates bias in the matching process.
In London specifically, the gap between stated availability and actual deliverable capacity is significant. Operators list capacity that is years from energisation. Grid queue positions are held speculatively. Proposals are sent against requirements the operator cannot genuinely meet on the buyer’s timeline. Armason’s live market intelligence filters these realities before any operator engagement begins — saving months of wasted procurement process.
Our process for London colocation starts with a structured brief: power requirement, density specification, redundancy level, connectivity needs, geographic constraints within London, timeline, and commercial parameters. We then engage the operators — across all London sub-markets and adjacent markets — with genuine availability matching that brief. We manage the proposal process, standardise responses, and provide clear evaluation across technical fit, commercial terms, and delivery credibility.
We work with buyers across all sectors — AI and HPC, enterprise compute, healthcare and regulated, and technology and SaaS. Minimum engagement is 1MW. All enquiries are handled confidentially.
What Armason Tracks in London
Live operator availability — capacity that is genuinely deliverable on a credible timeline, including pre-let opportunities not publicly advertised.
Sub-market power positions — which sub-markets have accessible grid headroom and which are queued out, updated continuously from operator and DNO intelligence.
Pricing and commercial terms — current wholesale and retail rates across London sub-markets, enabling structured commercial benchmarking from the outset of every engagement.
Build programme timelines — which operators are delivering new capacity, at what scale, and on what timeline — including facilities pre-energisation where pre-let terms are available.
High-density availability — the subset of London operators genuinely capable of supporting liquid or hybrid cooling at 30kW per rack and above for AI and HPC workloads — a significantly smaller group than those who claim the capability.
Related
Data Centre London
The full London data centre market — sub-markets, constraints, and how Armason operates across the region.
Data Centre Colocation
What colocation is, how it works, and what to look for in a provider — the complete guide.
Data Centre Cost
What London colocation actually costs — pricing structures, market rates, and total cost of ownership.
Looking for colocation in London?
Tell us what you need and we’ll give you a clear picture of what is genuinely available, what the timeline looks like, and who can deliver it. No broker lists, no generic introductions.