While price increases in softwood lumber have pushed new home costs higher due to homebuilders’ extensive use of the material, estimators for all other building types have felt the pinch as well.  Several contractors working on everything from transit systems to high-rise office buildings say that the cost of lumber, particularly for use in concrete framing, is hurting their bottom lines. Contractors also report difficulty in acquiring several products—including softwood lumber, steel, copper, aluminum, insulation, roofing materials and PVC—in adequate quantities, with some suppliers even canceling original sales when other customers can pay more. …U.S. contractors are trying to plan the rest of their purchasing year and see higher [lumber] tariffs in the fall as yet another hurdle. “Most suppliers are predicting that pricing will begin to level off in the summer and continue to drop over the next year,” Lawrence says.