As the most exposed part of the building, the roof faces some of the biggest challenges—from 70-degree sunshine in the summer to -40 degrees and snow loads in the winter. In cold climates, a roof must be properly sized, well-insulated, well-sealed, and reliable under extreme conditions. The best option in a cold climate is a cold roof, which contains a continuous air vent (ideally a 2-inch air space) between the roof insulation and the sheathing to prevent indoor heat and moisture from reaching the top of the roof.