I knew I should have bought the linked fire angels that Tesco were doing a couple of weeks ago for £5
You can get a combined heat/smoke alarm. That would cover you.
Know this is over a week old but the same deal is available with free delivery via their eBay listing: https://www.ebay.co.uk/itm/Radio-Interlinked-10-Year-2-Smoke-Alarms-1-Heat-Alarm-Kit-Firehawk-W-Series/303733429093
Interesting to see what insurance companies that operate across the UK do with this. From what I can remember they don't ask questions related to local legislation, or have anything similar. Will they discriminate between similar properties in Scotland and England, based on this? ie similar house, similar area/risk level, but different price/policy due to legislation in the country? In theory houses that have these installed should get cheaper insurance, similar to having better locks on your doors, burglar alarms, etc.
I appreciate this isn't the place for getting political, but it's also just another tax on the poor. The Scottish government site even states £200+ for an average home, and I can see a world where insurance companies trying to use it as a loop hole, refusing to pay out for contents damaged if homes don't meet the legislation. It's also ambiguous as to how many carbon monoxide detectors you need (could be interpreted as in rooms with carbon burning devices - so 1 for boiler room, 1 for cooker room, 1 for gas fire or log burner room - or is it 1 in houses which contain carbon burning devices...) They really should have at least set up a list of compatible devices (since so few are) and partnered up with each of the companies that make the devices to ensure they were making enough to meet demand, and also to offer discount for bulk buying with the power of a country.