The building materials used for your home can have a huge impact on the quality of the final product. There are chemicals that could have side effects affecting your health, there are building materials that are outright dangerous, such as lead and asbestos, and then there are things that could shorten the lifespan of your home or cause issues that need to be repaired later.
Take for example green lumber. This is lumber that hasn’t been kiln-dried, so it has a high moisture content. While this might be ok for some buildings in certain areas that have high heat, in many homes, they will lead to mold growth, popped nails, and other issues.
Because of the high moisture content in green lumber, it is a lot cheaper to buy, but it is not going to be providing savings over time if it is used in a building where it can’t dry out properly. It is also prone to changing shape as it dries which can cause all kinds of structural issues.