UK: Why you cannot get a mortgage for a lot of high-rise buildings?
 

Hello guys,

I've always liked skyscrapers so I was checking available places around London and I've got the following doubt.

It seems you cannot get a mortgage in a lot of high rise buildings (mostly ex-council towers), however I've then seen some buildings that were as old as these ex-council properties, they've gone through some modernisation process and then it seems that you can get a mortgage in those after the change :S

I was wondering:
* why is that you cannot get mortgages in a typical UK ex-council high-rise building?
* what's done when one of those buildings go through a modernisation process so that its situation changes from a lenders' point of view?

I was asking in another local forum but we don't seem to know why this is the case; so looking forward to understanding this...

Many thanks.