Don't understand the question. Didn't you figure out how much material (and labor) you needed as part of the original quote? Or are you preparing to quote and are trying to figure out how to price in the hips and ridges? Call me a dumb ruffer, but we try to measure the lengths of the hips and ridges and calculate the product need accordingly, plus a wastage factor for the shingles/panels/tiles at the diagonals and the ridges. Is the "owner" the property owner or the roofing company owner? If the former, then why is it his business, and if the latter, then why is he in this business?
I gotta buy the hip "n" ridge, so the customer has to pay for it. FK me.....what's to figure out?