Common Definition: 2-D refers to two dimensional measured drawings.

Unauthorized Definition: Two dimensional drawings are abstract representations of buildings, lacking depth information. So these drawings are often hard for homeowners to read. It takes training and practice to understand the information presented. Some unscrupulous pros employ this lack of understanding to trick homeowners. If a homeowner doesn’t understand a drawing, it’s the pros job to explain the issues.

On the jobsite, one may overhear an architect calling an engineer two dimensional, because they’re only interested in the building’s structure.

Sound Like a Pro: The terms “2-D” and “two dimensional” are used interchangeably. Unlike perspective drawings, 2-D drawings are scaled and measurable. Which is why they’re used for blue prints. They accurately convey measurable construction information. Floor plans are two dimensional representations of building floor layouts having measurements in two directions, length and width. Building elevations and sections show width and height.

Fun Trivia: Euclid of Alexandria lived around 300 BC and is considered the father of geometry, especially plane geometry. Euclid is the anglicized version of the Greek Εὐκλείδης meaning “good glory”. According to Euclid, a plane is a flat surface that extends in all directions to infinity. As opposed to a point that has no dimension. Or a line that has one dimension. It takes two points to define any location on a plane. That’s why a plane is called two dimensional. Charts with two axes are 2-D. A sheet of paper is considered a finite 2-D plane since thickness is negligible. So is the surface of a flat wall, floor or ceiling. Circles, squares and rectangles are all two dimensional objects, meaning they can be inscribed on a flat plane. Some people married to architects think they can be rather two dimensional emotionally.