Is there are Legal Limit to Number of Occupants

Hi

Is there a legal limit to the number of people that can live in a rented property with 1 bedroom? I am unsure if its let privately or through an agent.

The flat above me is one bedroom, about 49 sq meters. There are 3 adults living it it.

They are extremly noisy, banging, exercising (jumping)sunday nigh doing weights and banging them on the floor etc.

I have spoken to them numerous times and whilst they say ok, they are just really noisy.

The number of people in the confimed place makes a differnce, is there any laws?

Thanks