BS 5839: Pt.6 acknowledges the advantages of the single, battery powered smoke alarm. They are simple to install and offer protection at very low cost. Battery powered smoke alarms conforming to BS EN 14604:2005 are recommended. Battery powered smoke alarms are typically suitable for owner-occupied buildings (existing buildings) with up to two storeys. Please note: if your property has multiple levels, it is recommended to have interlinked alarms. This is to ensure you receive the earliest possible warning of fire.
Single story tenanted properties were allowed in the last version (2004) of this standard to be fitted with Grade F alarms. This has now been changed to a grade D requirement. As an aside, landlords have now been found liable in cases where tenants themselves have disabled an alarm. For this reason, it is unlikely that landlords will be able to trust tenants to adequately look after a smoke alarm. The Code highlights the fact that battery powered smoke alarms are also only suitable for owner-occupied properties if the likelihood is, that batteries will be replaced within five days of a low battery signal.