Layout of Construction Drawings 151
Drawings and permits are also needed for residential projects when substantial plumbing work is to
take place. For small projects, a licensed plumber can submit the information required to obtain a permit.
A professional engineer also provides the required drawings and reports for a septic-tank installa-
tion. A sewage permit must be obtained. A septic tank is installed where a sanitary sewage connection
to a municipal treatment facility is not possible.
Concept and designs are the first stage of any project. When established, the next stage is construc-
tion drawings. Once a floor plan is complete, it is passed over to the mechanical engineer to produce
plumbing drawings. The drawings become part of the construction-drawing set.
In some residences and commercial structures, a separate plumbing plan is drawn to show fixtures,
water-supply and waste-disposal lines, equipment, and other supply and disposal sources. These iso-
metric drawings are much easier to understand and are invaluable to those responsible for preparing
material estimates and to the craftspeople responsible for installing plumbing systems. The mechanical
division of a set of construction drawings will include, in addition to plumbing plans and details, drawings
for any heating, ventilation, and air-conditioning systems that a building might contain. Frequently, the
drawing sheets in the mechanical division are identified by the designating letter M in the title block. How-
ever, remember that in the order of drawings, sheets containing heating, ventilation, and air-condition-
ing drawings will precede those for plumbing.
6.7 ELECTRICAL DRAWINGS.
The final group of working drawings is usually the electrical drawings. Architects usually hire electrical
consultants to design the electrical services in buildings (unless they have electrical engineers within the
firm). The electrical drawings show the various electrical and communication systems of the building,
and they provide the client, the builder, and the permit department with the complete power layout for
the project. The electrical cover sheet indicates all electrical specs, notes, and panel schedules. This
sheet includes the specification of supplemental electrical panels if required. These drawings are typi-
cally part of the construction-drawing set. They typically include electrical power and lighting plans,
telecommunications, and any specialized wiring systems such as fire or security alarms.
Electrical drawings show the location of electrical circuits, panel boxes, and fixtures throughout the
building, as well as switchgears, subpanels, and transformers when they are incorporated in the build-
ing. The electrical drawings are submitted with the construction drawings for a building-permit applica-
tion. In some cases, they are submitted separately to obtain an electrical permit. Electrical plans are nor-
mally numbered E-1, E-2, E-3, etc.
Power Plan.
The power plan is a drawing of the floor plan showing all required outlets, locating panels, receptacles, and
the circuitry of power-utilizing equipment and special systems. The designer or architect will often draw a
power plan and dimension these locations. This is important to the engineer, especially if the connection
must be at a specific location or height or if it is floor-mounted or mounted within a fixture. Figure 6.21 shows
two examples of electrical layouts, one for a residence and the other for a commercial installation.
If a power plan is not provided, then the engineer draws it. This document indicates all outlets and
circuitry, electrical-distribution system, riser location, routing of service, design voltage and amperage,
and transformer size and location. It is an engineering drawing separate from the architectural set.