For hundreds of years architectural drawings were drawn up and reproduced by hand with ink on paper. These scale drawings were drawn according to standard conventions and used as building plans, working sketches, and as records. During the twentieth century technical advances changed the way draftsmen performed their job. The introduction of digital technology has caused a switch to computer aided drafting, or CAD.
The origins of the detailed plans of structures common to modern times was in the Renaissance, when artists made detailed sketches of classical buildings and began planning buildings that they imagined. In those days, the renderings did not include measurements and the conventions for detailed plans had not yet been set. Builders were expected to follow the illustration and work out the details.
As building became more complex, the art of drafting the plans advanced so that everything was spelled out in detail. Working up the plans including all the levels of detail became the process for spelling out engineering and construction problems before beginning the actual building. Creating detailed plans helps to avoid construction delays, to make cost estimates and to help the builder decide to commit to a project.
Eventually, the conventions used in modern architecture were adopted by the architects who prepared the plans. Certain views became standard, such as floor plans, which are horizontal views of the floor of a building usually at a height of three feet, showing how all the objects are arranged. This includes the walls, locations of windows and doors, fittings, stairs, and sometimes furniture in solid lines.
Another view is an elevation, which might be the depiction of an exterior or interior wall of a building. A cross section, similar to a floor plan, is a vertical plane section which cuts through a building. All these are drawn as orthogonal views, which means they are depicted with opposite sides parallel, in other words, the sides do not converge as in a perspective view. These are combined to create comprehensive plans for the building, used at stages to solve engineering problems or construction guides.
Copies of plans at first needed to be laboriously redrawn by hand, which was done on special paper such as vellum that could not shrink or stretch. When the blueprint process was developed, making accurate copies was simplified. Another advance was the switch to tracing paper, which allowed for much easier copies to be made of building plans.
Better tools such as adjustable squares and technical pens cut down on the time and labor needed to produce renderings. Technical drafting aides like the parallel motion drafting table and transfer lettering also helped to reduce the labor in producing drawings.
By far the biggest advance for creating architectural drawings came with the application of computer technology to this discipline. CAD software programs have taken over the production of building plans and have increased both the capabilities and speed of completion for planning structures. The choices for rendering details and materials and solving engineering challenges have been simplified. Digital plotters have made reproducing accurate prints an easy matter