Is it possible to houseshare very cheaply in London by using bunkbeds in the rooms?
In the UK registered landlords have strict rules to abide by, e.g the house needs a HMO license (house of multiple occupancy) if there are more than three people living in it. Fire safety is one of the main requirements, and I doubt a license would be given if there were bunkbeds and the house was over crowded. That’s not to say that there are not unregistered illegal landlords out there who would do something like that, but you should stay well clear of them, as house may be dangerous and you might not get a tenancy agreement from them (or deposit back). There are bound to be many houses with twin rooms in London which would have cheaper rent than a room on your own.