Numbers Dancing At A Party - Floor Gives Way

In Manchester in 2014 the floor gives way when large numbers are at a party.
Fortunately no deaths because the cellar below is only about three feet deep. But many other houses in the area have deeper cellars.

(Read more in the Daily Mail on line.)

Public buildings and lifts (elevators if you are reading this in the USA) list the maximum numbers and weights allowed for safety. But somebody has to be able to restrict numbers and count how many in every room. Add to that weight on the floor the effect of everybody jumping in unison. Plus the fact that the landlord is not legally allowed to enter unless the tenant requests and permits an inspection. Have health and safety any suggestions?