The Building (Scotland) Regulations 2004

B. On condition that this work, service, fitting or equipment is to a standard no worse than at present.

24.  Any work associated with the replacement of a fitting or equipment, in whole or in part, by another of the same general type, including a sanitary facility (together with any relevant branch soil or waste pipe), rainwater gutter or downpipe, solid fuel combustion appliance, electrical fixture, ventilation fan, chimney or flue outlet fitting or terminal, fire hydrant or main, lift or escalator, solid waste chute or container, kitchen fitments or other fitted furniture and ironmongery. Except-Any door, window or rooflight. Any oil firing or gas fired boiler.