Land Securities has committed to the £260m mixed-use development of 1&2 New Ludgate, in the City of London.
The 379,000 sqft scheme is located near to St Paul's Cathedral and will comprise of two distinct buildings with a new public piazza between them. 346,000 sqft will be office space, with 33,000 sqft of restaurant and retail space at ground and basement levels.
Colette O'Shea, London Head of Development at Land Securities, said: "Our decision to commence the speculative development of 1&2 New Ludgate reflects our confidence both in the City office market, where we believe supply of new space will be constrained in 2015, and in the quality of the attractive and highly efficient office space we are creating.
"1 & 2 New Ludgate will be a striking, flexible and contemporary addition to one of London's most historic locations with appeal to a wide range of occupiers seeking space in central London."
Demolition work on the site has already been completed, with Skanska Construction appointed as the main contractor for the scheme.
Construction will start on site in August, with a completion date of April 2015.