By Alison Rice. For the best prices on building materials, go to bat for your contractors. That's what Keystone Custom Homes did with its roofing, communicating directly with its contractors' suppliers and staving off an expected 5 percent increase in shingle costs.

"We went to the local suppliers and promised we'd be using this one kind of shingle" for the 250 homes Keystone expects to close this year, says Jim Hostetter, director of estimating and options for Keystone, a two-time America's Best Builder winner based in Willow Street, Pa. Quantity wasn't everything. The builder also agreed to use just one shingle color--driftwood--as standard. "By agreeing to use one color it makes their supply chain a lot easier," Hostetter says.

The builder has used the approach with other products as well, slicing Keystone's costs on lighting materials by 5 percent to 20 percent, depending on the supplier.

There are caveats to this cost-cutting technique. "I wouldn't pick a new brand and commit to using it for a year," Hostetter advises.