Only a two floor extension rather than the three floor one shown in those photos. So keeping at least some part of the existing house. The original planning application was for a three storey building but that was withdrawn - it sounds like it got a pretty unenthusiastic reception from the "Delegated Panel": http://planbuild.southwark.gov.uk:8190/online-applications/applicationDetails.do?activeTab=summary&keyVal=_STHWR_DCAPR_9558415 The second application, which was granted, was for a two storey extension: http://planbuild.southwark.gov.uk:8190/online-applications/applicationDetails.do?activeTab=summary&keyVal=_STHWR_DCAPR_9562498 As others have said, they're also knocking down the old workshop immediately behind the house and building a second new house on the empty site behind that on Landcroft Road, which is currently the back garden of #263: http://planbuild.southwark.gov.uk:8190/online-applications/applicationDetails.do?activeTab=summary&keyVal=_STHWR_DCAPR_9561702 (If you're interested, you can click through "related documents" to see plans and drawings as well as all the associated paperwork from the applications.)