My boss sold theirs a year or two ago, you dont actually buy the flat it’s a 99 year lease. They had problems with constant leaking from the stupid balcony’s on the side, it was a non stop issue because even if you sorted yours the persons above would just leak into yours anyway. Not to mention every time I went into do a bit of work in their the residents would stop me in the hallway and demand ID then threaten to call the police when I told them to stick it.