Developer Derwent is preparing to start its most ambitious London scheme to date – the redevelopment of the former Saatchi building at Charlotte Street.

Brookfield Multiplex will deliver the 380,000 sq ft mixed-use development in Fitzrovia, which is one of two major projects due to be started by June 2016.

The project start, which has been delayed for several months, will see the contractor deliver a part refurbishment and part new build (pic below).

A substantial proportion of the existing structures are being retained to reduce waste and carbon emissions and the construction programme.

The second major job in Paddington, known as the Brunel building will be delivered by Laing O’Rourke.

Its structure echoes as a smaller version the landmark Cheesegrater offices at 122 Leadenhall St, which was Laing O’Rourke’s first major high-rise project in London.

The 240,000 sq ft office is planned on one of the last sites in Paddington Basin on the banks of the Grand Union Canal and opposite Brunel’s Paddington Station,which lend the scheme its engineer’s name.

It will rise to 17 floors and is designed with an external supporting steel diagrid support frame to afford column-free floorplates.

Designed by Fletcher Priest Architects and engineered by Arup, construction at the 55-65 North Wharf Road site is due to start in early 2016 and complete in the first half of 2019.

In a third quarter trading statement this morning John Burns, Derwent chief executive officer, said: “The current year is our best ever for lettings.  We have also successfully recycled some more mature assets into several major opportunities and the Group’s development activity demonstrates confidence that the high level of occupier demand for our product is set to continue.”