Neighbours Boiler Flue in Shared Drive

Lia57

Can anyone help re my neighbour’s flue extending excessively (30-35cm) onto the shared drive?  The house is currently being renovated by the foreign owner’s agents and will eventually be let.  The agents are saying the flue meets current rules and regs but although there’s plenty to read about how high the flue should be placed and how far it should be from openings, there’s nothing about how far out the actual pipe/flue can extend (horizontally)  into a shared driveway.  Apart from the safety aspect it’s encroaching into the driveway and looks really ugly. Any ideas?  Thanks