Deck The surface, installed over the supporting framing members, to which the roofing is applied.
Dehumidistat A control mechanism used to operate a mechanical ventilation system based upon the relative humidity in the home.
Designer One who designs houses, interiors, landscaping or other objects. When used it the context of residential construction it usually suggests that a designer is not a licensed architect. Most jurisdictions don't require an architectural license for most single-family construction.
Dormer An opening in a sloping roof, the framing of which projects out to form a vertical wall suitable for windows or other openings.

Double coverage Application of asphalt roofing so that the lapped portion is at least 2 inches wider than the exposed portion, resulting in two layers of roofing material over the deck.
Double hung window A window usually of wood with two vertically sliding sashes. This was a very common window design up to the 1950's.
Downspout A pipe for draining water from roof gutters. Also called a leader.
Drip Cap A molding placed on the exterior top side of a door or window so as to cause water to run off or drip on the outside of the frame of the structure.
Drip Edge A non-corrosive, non-staining material used along the eaves and rakes to allow water runoff to drip clear of underlying construction.
Drywall An interior wall finish consisting of 4’ x 8’ panels of paper covered gypsum plaster .