A total of 117 apartments with ancillary retail units and undercroft parking is being built on Bromley Road, Lewisham.
It is the largest current project for the Nottingham-based contractor. Client is developer Lowbridge and completion is scheduled for February 2014.
Clegg Construction managing director Simon Blackburn said: “We’re delighted that work has now started on our latest major project. Clegg Construction has an excellent track record of delivering large-scale projects of the very highest calibre and this scheme will be no different.”