To begin with the nitty gritty, we start with a custom made 18′ trailer. The shell structure utilizes SIP’s (structural insulated panels) for greater insulation and strength. The door and windows are reclaimed along with the metal siding band that encompasses the entire girth. The lower wainscot is cedar lap siding while the upper band is vertical cedar plank on the sides and cedar shakes on the endwalls.” – Rocky Mountain Tiny Houses