UK data centres face tight supply as builds lag demand

Savills analysis shows UK data-centre vacancy fell from 27% in 2016 to 8% in Q1 this year. London’s vacancy is 7%, and the city holds 1,637MW of the UK’s 1,803MW live capacity. Only 48MW of IT capacity was delivered in Q1, and 242MW is under construction.

Savills attributes the tight supply to London’s existing cloud ecosystems, high network density and established availability zones. Developers outside the capital prefer sites with existing infrastructure and lower development risk. Manchester is identified as a secondary centre; beyond those cities activity is limited.

Delivery volumes have varied in recent years. The UK completed 191MW of IT capacity in 2024 and 231MW in 2025. Early 2026 output was 48MW. Of the 242MW under construction, about 66MW is scheduled to finish between Q2 and Q4 this year, limiting near-term additions.

Energy availability is shaping which projects can proceed. In parts of West London developers expect multi-year waits for firm grid capacity, prompting operators to consider alternative power options to bridge gaps to grid supply.

Rupert Duckworth, associate director at Savills Data Centre Advisory, noted, “National supply is expanding on paper, but much of the pipeline remains early-stage and uncertain.” He forecast growth in the North East because of renewable infrastructure and grid connectivity, while characterising that as a medium-term diversification rather than an immediate relief.

Lydia Brissy, director of European research at Savills, observed that some developers are treating alternative power strategies as a way to secure site positions while awaiting grid capacity.

Pre-letting is common, with future capacity frequently committed before completion. Savills states national capacity is likely to rise over the long term, but immediate options for rapid expansion are few as projects face tighter regulation, constrained power and longer development timelines.