Cantillon will carry-out the demolition which is due for completion early next year with Sir Robert McAlpine on board as pre-construction advisor to oversee the management of the project.
A main contractor will be appointed in mid-2013 and the development is expected to be completed in 2015.
Riverwalk will be a collection of 113 one, two, three and four bedroom luxury apartments and penthouses spread across two organically shaped buildings.
The development has been designed by Stanton Williams and Knight Frank and Savills have been appointed as Joint Selling Agents.
Jonathan Goldstein, Chief Executive of Ronson Capital Partners, said: “We are excited to start work on Riverwalk, which will be a development of outstanding quality at the heart of Westminster.
“The team behind Ronson Capital Partners has extensive experience of delivering highly specified Central London projects with a focus on excellence in terms of design, detail and service.
“In addition, we have chosen a selection of excellent partners, contractors and advisors who have the experience and expertise to bring this exceptional project to life.”