: These account for the size of the windows, the wall material, and how much fuel (desks, paper) is actually in the room.
: How the loads (furniture, people, snow) change when the building is burning.
They are easy to use but often unrealistic because they never cool down. :
The "long story" of fire design for steel structures within the Eurocode framework is a journey from simple, "one-size-fits-all" fire tests to sophisticated engineering that mimics real-world physics.