Fires can no longer spread through closed doors or through one-way exits. Additionally the firestorm weather type can no longer create a fire within a player house such as, for example, within an outdoor garden they might have. This doesn't mean a fire cannot spread into a house however if a door is left open (so either way you'll be able to put it out).

Penned by my hand on Gosday, the 17th of Lanosian, in the year 479 MA.