Unless it is a super-recent experimental … no. I burned down a house just two tiles from another house, and the fire didn’t jump between the houses. Nor did any of the grass even get singed.
I would still pack a large fire extinguisher … just in case.
[Edit] I would hazard a guess that KA101 means that if you start a fire in a deep pit, it will not spread, even if that deep pit is (for example) in the middle of a house. Anyone willing to do some SCIENCE to see if that is the case?
(I will in 2 hours, if no-one else is keen :P)[/Edit]
[Edit2] SCIENCE! has been performed. It turns out that
a) Pits can only be built outside. You can’t build a pit indoors … although you CAN build a stone fireplace indoors, despite one of the requirements being a lvl 2 digging tool (required to build deep pits)
b) A small fire inside a deep pit won’t spread (like all small fires), and the smoke is very small (no smoke more than two tiles from the pit)
c) Unlike most fire containment methods (IE. ovens, braziers, fireplaces, etc.), the deep pit fire can progress to a raging fire, if enough fuel is added. This increases the temperature and fuel consumption of the fire.
d) Unlike normal raging fires, though, this fire refused to spread to either of the three adjacent wall tiles, or the pile of clothing nearby. It started drizzling in the middle of the experiment, but I feel confident in saying that raging fires in pits do not spread. In addition, the smoke from the raging fire never reached 5 tiles away from the fire, and rarely reached 4 tiles from the fire.[/Edit2]