When building a house, you probably want to avoid spending too much, but at the same time, you don’t want to end up with problems because of the building materials that you use. This is a fine balance to strike, but it is possible as long as you are fully aware of what consequences the use of a particular building material could be.
Take green lumber for example. This is lumber that hasn’t been dried in a kiln but instead has a high moisture content. This will not be a problem in some implementations, but if you are using it for building a home, you could be facing mold issues, popped nails, unsightly cracks, and other problems as the wood keeps drying after it has been installed. Depending on the temperature and humidity in the area where you live, this type of lumber could take a different length of time to completely dry out.
Usually, green lumber will not be worth the savings if you are planning on using it for an expansion of your home or something similar.