Drawings show electrical systems in a conceptual layout, but not necessarily a practical layout. The estimator must design portions of the project in order to perform an accurate takeoff. Before beginning a takeoff, the estimator should analyze the project by systems and sketch practical layouts of the work.
This is not a design of the electrical work, but rather an installation design of the work. Remember, the contractor is an installer, not an engineer.
The following are possible portions of the work that the estimator should design before beginning quantifying the project:
- Feeder conduit routing.
- Feeder trapeze hanger’s layout.
- Panel board locations – if a design / build project.
- Combining of branch circuit home runs.
- Circuits that require voltage drop adjustments.
- Identify any portions of the work that can be prefabbed.
- Proper material selection as per the NEC or the AHJ.
This will take some time, but it is time well spent. Remember – accuracy is the key in estimating.
Remember, estimating is expensive, poor estimating is costly, but quality estimating is profitable.