Generally, working or project drawings may be divided into the following major categories: civil, architectural, structural, mechanical, electrical, and fire protection. In SEABEE construction, however, the major categories most commonly used are as follows: CIVIL, ARCHITECTURAL, STRUCTURAL, MECHANICAL, and ELECTRICAL sets of drawings. 

Regardless of the category, working drawings serve the following functions:

. They provide a basis for making material, labor, and equipment estimates before construction begins.

. They give instructions for construction, showing the sizes and locations of the various parts.

. They provide a means of coordination between the different ratings.

. They complement the specifications; one source of information is incomplete without the others.

Civil working drawings encompass a variety of plans and information to include the following:

Site preparation and site development

Fencing

Rigid and flexible pavements for roads and walkways

Environmental pollution control

Water supply units (that is, pumps and wells)

Depending on the size of the construction project, the number of sheets in a set of civil drawings may vary from a bare minimum to several sheets of related drawings. Generally, on an average-size project, the first sheet has a location map, soil boring log, legends, and sometimes site plans and small civil detail drawings. (Soil boring tests are conducted to determine the water table of the construction site and classify the existing soil.) Civil drawings are often identified with the designating letter C on their title blocks.

A SITE PLAN (fig. 10-11) furnishes the essential data for laying out the proposed building lines. It is drawn from notes and sketches based upon a survey. It shows the contours, boundaries,

Figure 10-11.-Example of a site plan with existing utilities.

roads, utilities, trees, structures, References, and other significant physical features on or near the construction site. By showing both existing and finished contours, the field crew (Equipment Operators) is able to estimate and prepare the site for construction and to finish the site (including landscaping) upon completion of construction. As an EA, you should be familiar with the methods and symbols used on maps and topographic drawings.

Site plans are drawn to scale. In most instances, the engineers scale is used rather than the architects scale. For buildings on small lots, the scales normally used are 1 in. = 10 ft or 1 in. = 20 ft. This means that 1 in. on the drawing is equal to 10 or 20 ft, whichever the case may be, on the ground. Since the engineers scale is the principal means of making scaled site plans, you, as an EA, should be thoroughly familiar with its uses.

On a set of project drawings prepared by an A/E firm, the physical information given on the site plan is taken from surveyor-prepared field notes or sketches. Other information contained on the site plan may also be used by the planners and estimators when figuring quantities of materials required, labor needed, and areas available for staging of equipment and materials. As an EA, you may be tasked with drawing a site plan or revising one. Outlines of some of the basic procedures in the development of a site plan follow.

1. Lay out the site plan from the surveyors drawing, showing boundary lines or limits of construction and existing trees and construction. Also note any existing features that must be removed.

2. Draw contour lines with dashed lines. Notice that if contour lines are placed on the reverse side of the drafting sheet, they make future changes or revisions easier.

3. Draw the proposed building and all surrounding construction, such as sidewalks and parking areas. Show the outline of the building wall with solid lines and the outline of the roof overhang with dashed lines.

4. Give the finished floor elevations of the building or buildings, garages (if any), and finished elevations desired on sidewalks and parking areas.

5. Review the existing contour lines. It is important that surface water not run into the buildings and other constructions, but rather towards a storm drainage system.

6. Place the dimensions. Locate the building and other constructions by a minimum of two location dimensions. If the building is not positioned parallel with the property line, more than two dimensions are required. Dimensions should be from the property line to the exterior wall of the building, not the overhang. Other dimensions necessary to be included are distances to road center lines, utility lines, easements, and any restrictions or obstructions to the site, such as utility poles and hydrants.

7. Double-check your drawing, taking a second look at the finish grade elevations, datum point, and other related information. A good technique is keeping a site plan checklist handy to make sure information given is complete and accurate.