A Nest smoke detector will be located in every room. This is overkill, especially with a sprinkler system, but the idea is to make it as easy as possible for you to escape a fire. The sprinkler system is intended to buy you time to safely escape, and reduce damage to property in one locale. When the system goes off, you would be notified of which room smoke was detected in. And while a Nest smoke detector can detect carbon monoxide, this will be unlikely since there will be no gas line.