London office construction is at an all-time high, with Deloitte’s latest crane survey recording 51 new construction starts, the highest number in the survey’s 20-year history.
Deloitte said 14.2m sqft of office space was under construction at present.
In the short to medium term, it predicted, institutional investors will challenge the dominance of public property companies.
Institutional investors are developing more than half the volume of new space started in the crane survey.
Chris Lewis, head of occupier advisory at Deloitte Real Estate, said construction activity had nearly doubled – from 7.7m sq ft in late 2014 to more than 14m sq ft – in just 18 months.
“London is building for business as developers respond to strong occupier demand,” he said.
“As new schemes begin to complete, London’s diverse mix of office tenants can look forward to a greater level of choice.”
The survey, Lewis said, highlights the balance between supply and demand.
With five years of previously low construction levels, pre-completion lettings are on the rise, according to Deloitte.
Nearly 6m sq ft, or 42%, of space currently under construction is already let, up from 38% in six months.
The financial and technology, media and telecoms sectors, which have signed for 2.3m sq ft and 2.2m sq ft of space, respectively, have largely driven the increase.