ok, well how about 3, but for apartment buildings and small buildings that would be terrible, ok lets do it like this....
Idea 1:
Properties|Smoke Detectors
1 Room | 1 Detector
2 Room | 1 Detector
3 Room | 2 Detectors
4 Room | 2 Detectors
5 Rooms|3 Detectors
6 Rooms| 4 Detectors
7 Rooms| 4 Detectors
8 Rooms| 5 Detectors
9 Rooms| 6 Detectors
10 Rooms| 8 Detectors
For larger Homes
15 Rooms | 10 Detectors
20 Rooms |15 Detectors
25 Rooms | 20 Detectors
30 Rooms | 28 Detectors
40 Rooms | 38 Detectors
50 Rooms | 48 Detectors
Idea 2:
1 Detector Per 50 Square Feet Per Floor (So like i have 100 Square Feet, and 2 floors, so i need 4 Detectors)