There has been rapid growth in the use of engineered wood products in the construction sector in recent decades. We evaluate the economy-wide impacts on CO2 emissions from fossil energy use of replacing carbon-intensive construction inputs, such as steel and cement, with lumber products in the US under an emissions constraint. We find that the ability to substitute lumber-based building materials increases production from the lumber and forestry sectors and decreases production from carbon-intensive sectors such as cement. Under a carbon cap-and-trade policy, the ability to substitute lumber products lowers the carbon price and the GDP cost of meeting the carbon cap, with more overall emissions abatement in the construction industry. We briefly review the broader impact of forest harvest on carbon levels in forests, critical to determining the full life cycle impacts of greater lumber use, but do not add anything new to this literature.