Architectural Drawing

All kinds of technical drawing are based upon the same general principles. Architectural drawings have to do with the representation and specification of buildings. The drawing of a building has to be made to a very small scale as compared with a machine drawing, which makes it necessary to use conventional symbols for the different parts. They differ also in that only one view usually is drawn on a sheet.

There are three general classes of architectural drawings:

1. Preliminary sketches: These are freehand studies of the arrangement of rooms, first made as very small "thumb-nail" sketches without using the scale, and when a satisfactory scheme is decided upon, worked up in larger freehand sketches to approximate scale.

2. Display and competitive drawings: These are more or less elaborate preliminary drawings of a proposed building, often including a perspective, and are rendered in water-color, pen-andink, or pencil to make them legible and attractive.

3. Working drawings: These form the most important class, and include plans, elevations, sections and detail drawings which when read with the specifications for details of materials and finish, give the working information for the erection of the building.

Plans.—A floor plan is a horizontal section taken above the floor represented. It shows all the walls with their doors and windows, gives the location of lighting, heating and plumbing outlets, and shows part of the stairways starting up or down from the floor. A plan is always laid out with the front of the building at the bottom of the sheet. Ordinary house plans are drawn to the scale of Y±' = 1'. Fig. 184 is a freehand sketch plan of the first floor of a house.

With this as a basis it is required to draw the plans of the house. The first floor as shown in Fig. 187, is drawn first, then the second floor and basement plans. Draw a horizontal line representing the outside face of the front wall. Complete the exterior walls and interior partitions. Frame walls are drawn 6" thick.. Locate doors and windows and draw them with the conventional symbols as shown.

In drawing the stairway first make a diagram to find the number of steps and space required. The rise, or height from one step to the next, is from 6" to " and the tread so that the sum of rise and tread is about 17 inches. On the plan the lines drawn represent the edges of the risers and are drawn as far apart as the width of the tread, as shown in Fig. 185. The entire flight is not drawn on the plan but is broken so as to show what is on the floor under it. The other end is shown on the plan of the floor above.

The second floor for a two story house is best planned by laying a piece of tracing paper over the first floor plan. Trace the exterior walls and locate stairways and chimney flues. The interior partition walls need not be continuous with the first floor. See that closets are provided for every room. Note that the second floor, Fig. 188, is for a cottage type and account must be taken of headroom under the roof.

The basement plan is shown in Fig. 186. It should be completely dimensioned as the construction of the house is started with this plan. Windows should be under the first floor windows. The furnace should be near the center of the house.

Elevations and Sections.—A front and one side elevation are shown in Figs. 189 and 190. In a complete set of plans the other side and rear elevations should be drawn. In drawing elevations start with the grade line as a base line. The figures show the information usually given on elevations. A wall section to a larger scale is shown in Fig. 189.

Details.—In addition to the quarter-inch scale drawings, larger scale drawings are made of such parts as cannot be shown with sufficient detail on the small scale drawings. Figure 191 is a typical sheet of details. As the building progresses the architect furnishes full size drawings made with soft pencil, for millwork and other details.

Symbols.—The usual symbols for doors, windows, fireplaces, etc., have been shown on the plans. Different building materials are indicated in section as shown in Fig. 192, and some of the standard wiring and lighting symbols in Fig. 193.