Chris and Phil get nerdy about the most underrated tool in your CD set: the residential project manual. They walk through key spec divisions and the small callouts that protect performance, like blower door targets, temporary heat, low carbon concrete mixes, and toxicity rules that keep bad products off site. You will leave with a clearer way to write, organize, and enforce specs so substitutions do not quietly wreck airtightness, durability, or indoor air quality.