There are some trees that have some kind of protection order on them. This doesn't mean that no work can be completed on them, it means that more steps have to be taken to make sure that the work is required and meets certain criteria. Some examples of these are Tree preservation orders (TPO's), Conservation areas and building planning orders.
We are able to find out if your trees are protected, and if so, get in contact with the appropriate people to investigate what work would be allowed.
Tree preservation orders and conservation areas are put in place to benefit the aesthetics of the tree and the surrounding area, if this is impacting negatively then there may be a case for intervention.