Lewisham does not seem to have a policy for implementing bike hangers, but Ive noticed on my street (Como Road) that there are a number of bikes now being chained to lamp posts and some people putting little bike lockers in their front yard.
My lease does not allow a front yard bike locker, but I have a couple of bikes that would certainly get more use if they were in a bike hanger.
If anyone feels that getting a bike hanger might be a good idea, here are some instructions as to how to go about requesting it (pretty much just sending an email).
http://lewishamcyclists.co.uk/lewisham-new-cycle-parking-requests/
Ive done this a couple of times over the past few years, and never received a response, but with the recent increase in cycling around London - its worth trying again.