 So last week, I asked economist Robert Dietz at the National Association of Home Builders, if lumber's relatively cheap, why are new homes still so expensive? Building material costs are 30% higher compared to 2019. A lot goes into building or remodeling a home, says Carlos Martin at the Harvard Joint Center for Housing Studies. There are a wide range of other materials whose prices have gone up. A lot of plastics, plastic-related products. There's been some variability with steel.