Evening all..just wondering if it is a building control requirement to have a mains fire alarm installed throughout the property when an extension has been built or walls knocked through to make a kitchen/diner etc. I have worked on a loft conversion last year and the building control officer insisted that there was a fire alarm system throughout the property, even though the loft was the only area been worked on. I'm thinking it's down to each council's requirements but just wondering if anybody knows? Cheers