We're at final sign off stage for a loft conversion making it 3 storeys in total. We have smoke alarms in every room except the two bathrooms, and on each landing/hallway. We have fire doors in the new loft. The building inspector has insisted on a smoke alarm in the under-stairs cupboard as well on the basis that there is a gas meter in there (meter is less than 2 years old if that makes a difference). The electrician has never heard of this and it's going to be a faff to do and I've only read about this requirement in HMOs. (long story but our builder wasn't very good at engaging with BC at the right points so this would be less problematic if he had discussed it properly with them at the time when the others were fitted). I have read the building regs and it refers to alarms in all rooms that 'present a high fire risk to occupants' - is a gas meter a high fire risk? or is it because it is under the stairs i.e. escape route. I should note that the hallway alarm is no more than 10cm from the cupboard door. Worth pushing back and possibly using additional fire protection (e.g. on cupboard door and lining of cupboard ceiling)??