Yeah. Where I live (I’m not in the US or Canada), inside apartments there are no smoke alarms and it’s not a building requirement for residential complexes, from what I understand. There are Fire and Safety requirements such as hoses and sprinklers in public areas, but inside an apartment? No. And I don’t think “Smoke detectors” themselves are a hard requirement either.

I wonder if it’s because buildings are not build of wood.

That being said, in commercial buildings, so like in my office, yes there are smoke detectors. But even so, I don’t think it’s a hard requirement as coming to think of it, not all offices I’ve been to have them.