A survey by Deloitte Real Estate has found that there is 9.7 million sq ft of office space currently under construction in the capital, across 71 schemes.
Significantly, more than two million sq ft is already leased to tenants prior to construction completion, showing encouraging occupier confidence, the firm said.
Deloitte Real Estate head of research Anthony Duggan said: “2014 is currently set to deliver the largest amount of space into the central London office market for 10 years.”
In the square mile of City of London, office constrcution has reached a five-year high with more than five million sq ft now being developed across 23 schemes. Nine new starts are recorded in this survey, totalling 1.3 million sq ft.
In contrast the West End has seen total construction activity fall 36% since the last crane survey six months ago, to 1.5 million sq ft. This market has seen a high level of completions with 1.2 million sq ft delivered in the past six months.
Mr Duggan added: “This latest report reflects the improving confidence being seen from both office occupiers and developers. Leasing activity of new space has increased and construction remains active with 28 new schemes on site this survey.
“We are now seeing rents move forward again following a pause over the last couple of years and this prospect, along with continued appetite from investors for prime stock and the improving economic outlook, will encourage further development starts over the next six to 12 months.”