Zack Dettmore installs vinyl siding with trim details that give it a more traditional look, then tours a Pennsylvania factory where a modular Accessory Dwelling Unit is framed, wired, finished, and prepared for delivery. Back in Walpole, Richard Trethewey explains a ceiling cassette HVAC system for the basement, and the crew installs a three-panel sliding glass door.

The show’s own verdict is on its page.