Legal starting points

The law starts by looking at neighbours as people who have property rights. When you own or occupy land, you are entitled to the normal enjoyment of a property in that locality. It is certainly not the case that you have to use your property so that no one else suffers interference (despite the often cited maxim sic utere tuo ut neminem laedere (use your own property in such a way that no one suffers harm))

Third century Roman lawyers already dealt with the problem of a ground floor cheese shop creating smoke from its fires which interfered with the enjoyment of the property above it. Where the cheese shop owner did not have a specific right to make smoke, they distinguished two situations:

The cheese shop owner would clearly be liable if he caused the disturbance because he intended to offend his neighbour. But

The cheese shop owner who unintentionally smoked out his neighbour would only be liable if the disturbance was not considered moderate. A medieval writer, Bartolus of Saxoferato, wrote:

“Sometimes the owner of the lower premises makes fire in the usual way for the ordering of his family, and then he may do it lawfully, and he is not liable if the smoke ascends unless he acts with an intention to offend.... But if the owner of the lower premises wants to make a shop or inn where he is continually making a fire and a great deal of smoke, he is not allowed to do so .“

The issue for the second (and most common case) was how to decide what was a ‘moderate’ interference. Now this has continued to be the problem faced by lawyers in subsequent centuries. They were not principally concerned whether the cheese shop owner was at fault in creating the smoke. It was enough that he caused it.