More and more people are paying rent to their mates - but this leaves occupiers unprotected and unsure of their rights.
The division between "freehold" and "leasehold" is a monster hybrid of medieval law and postwar housing booms, unique to England and Wales. The cross-party move for reform has been stymied by Tory leadership convulsions. Now campaigners hope it can get back on track.
Yes, prices could crash. No, it won’t help you.