I hear the term "builder-grade materials" a lot, but it's not an industry term. There's no official definition for it. When I hear someone say it, they usually mean it in a negative way. They're saying that builder-grade materials are the cheapest and poorest quality possible and are usually lower quality than materials available to the general public. That's not really the case though.
Let's first talk about the difference between a spec home and a custom home.