People in control of buildings and other structures are responsible for ensuring that they are maintained in a structurally safe condition, even if they are unoccupied. Vacant buildings and structures must also be kept secure, to prevent unauthorised entry, or to prevent them becoming a danger to public health. The operators of active construction sites must also ensure that they are kept secure against unauthorised entry if there is a risk of injury to the public.
Moreover, if a building is in a “ruinous and dilapidated state” which is “prejudicial to the amenities of the neighbourhood” the local authority may require the owner to carry out any repair or restoration works necessary in the “interests of amenity”.
If you have control of any property you should ensure that it is regularly inspected and maintained by properly qualified professionals (such as structural engineers, surveyors or architects) to ensure it does not deteriorate to such an extent that it becomes a danger to others and that adequate controls are in place to prevent unauthorised entry.