Before calling the roofers and spending that $500, know the score:

• You must use either metal or asphalt roofing materials that are designed to reduce heat gain—the amount of heat transferred into a home.

• Metal roofs must have appropriate pigmented coatings.

• Asphalt roofs must have appropriate cooling granules.

• Asphalt materials can be either traditional shingles or modified bitumen (rolled asphalt sheets).

How much roof do you need?

Get an estimate by figuring the square footage of the footprint of your home and adding about one-third more to account for roof pitch, overhangs, dormers, gables, and so on.

Roofing contractors often quote in terms of “squares.” One square equals 100 square feet. So if a roofer says your house is 20 squares, it means it’s roughly 2,000 square feet—20 times 100.