If a tree on your property encroaches on a neighbour’s property, either with overhanging branches or invading roots, you must obtain the neighbour’s consent to address the encroachment. However, you are entitled to trim the branches or roots that encroach on your property, but only up to the property boundary.
In the case of Vogel v Crewe and Another the court found that the benefits of conserving the trees (aesthetic pleasure and provision of shade and oxygen) had to be weighed against the damage caused by overhanging branches. The court held that the owner was entitled to cut down branches that were overhanging over his property, but only after giving the owner of the tree notice.
If a tree causes damage, you can request the owner to remove the branches or roots. If the owner does not respond, you may apply for a removal order or remove the branches or roots yourself and recover the costs. Legal action should be pursued as a last resort as this can severely impact the relationship between neighbours.