As a minimum level of protection, one should fit two smoke alarms - one Ionisation and one Optical. If your home has more than one floor, at least one smoke alarm should be fitted on each level. A combination of optical and ionisation, preferably interconnected will give the best protection. For maximum protection a smoke alarm should be fitted in each room of the house (except kitchen, bathroom or garage - heat detectors are recommended for these rooms). Again a mix of optical and ionisation alarms is recommended and ideally should be interconnected.