HomeAdvisor’s Framing Cost Guide provides average per square linear foot labor prices for framing a new house, addition or roof. Discover our cost calculator for lumber or metal construction materials, and our framer contractor rate estimator..HomeAdvisor’s Roof Coating Cost Guide provides prices per square foot for applying sealants including silicone, elastomeric, uniflex, hydrop stop and others. Calculate costs for waterproofing foam, metal, asphalt, flat and other roofing materials..Average house building cost per square foot can be very complex to estimate. Your home will vary in price from others according to size, but also according to methods and materials used in construction, and how much of the job you will do yourself..Let’s Discuss Construction Cost per Square Foot. Let’s talk about the mythical, mystical construction cost per square foot for building a new house or addition..