Keltbray has begun demolishing the 17-storey St Alphage House 1960s office block in London to pave the way for a 500,000 sq ft office scheme.

The Developer has lined up its contractor Brookfield Multiplex to start on two major buildings, comprising an 18-storey west building of 300,000 sq ft and 14-storey east building offering 20,000 sq ft of space.

The 500,000 sq ft project will boast roof gardens with spectacular views over St Paul’s and the City

Keltbray has had to erect the largest freestanding tower crane in London to carry out the floor by floor demolition.

The 72-m high, 60-tonne tower crane can lift up to 12 tonnes.

Keltbray will construct a major steel gantry to house diverted utilities including the local district heating and cooling pipes, as well as several high voltage cables.

The firm will also work around the Crossrail network and Moorgate Station, which will remain operational throughout the project

On site, there are the remains of St Alphage Church which dates back to around year 1110, and of the Roman Wall from the late 2nd or early 3rd century.

“There are likely to be archaeological finds associated with the site too, especially the Wall’s moat, which was once London’s main rubbish tip.”