The present smoking ban makes smoking in many private properties illegal. It does these by defining these private properties as public. Just because a member of the public may be allowed access to these properties does not make them public.
Instead the law should ban smoking in true public places including all government (local and national) offices and maybe even parks (of at least a certain space)
Why is this idea important?
It is important to not allow private property to somehow be controlled as if it was publically owned.
We all, for example, have the choice of whether to visit or work in a pub.; just as the landlord has, or should have, the right to refuse to serve/allow entry of anyone.