Fire spread in a building.

Ok, let's say you have a 3 story building that is very flammable and pretty much has no fire safety measures installed.

You start a fire in a room at a corner of the building on the first floor.
Will the fire spread to the room upstairs faster, or the an adjacent room faster?

How fast does the fire spread to other rooms?

setting fire to your university is HIGHLY ILLEGAL

but fun.