otherwise the tt building will have deemed to not comply to b one of the building regulations which i don't want to go into too much detail but basically what it is that with effect from nineteen ninety one the smoke alarm smoke detector bill came into er operation and it was brought in into the nineteen ninety two building regulations when they were amended from the nineteen eighty five regulations that states now  any new build homes shall have and be fitted with a mains operated, with battery backup, smoke detection system.