Prepare Blueprints

When preparing an electrical estimate, there are several things that you can do to the blueprints to speed up your material take-off. These will smooth the process of entering information into your electrical estimating software and increase the accuracy of your bid. First, take some time to review the blueprints before starting the take-off. Then consider using the following techniques:

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Highlight key items - Always use the same color of highlight to mark areas that you have questions about(I prefer to use yellow). This will call your attention to it later, so you do not forget. You will cross it off when you find out the answer.

Mark all firewalls with a highlighter. When you do your material take-off and see that conduit must be run thru a firewall, you will include fire pads or fire putty. The same thing goes if there are outlets that are located in the firewall. You will include fire pads or fire putty on your take-off for outlets located in firewalls.

Highlight where conduits penetrate concrete walls or floors.

When you do your take-off, include core-drilling and fire calking or fire pads as necessary.

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Verify scale - Verify that the scale noted on the plan legend is correct. Sometimes the scale on the plans is incorrect; the plans may have been reduced to ½ size, or shrunk to fit the paper size. A quick way to check the scale is to measure a door opening on the plan. Doors are generally 36” (3 feet) wide in commercial work. You can measure the 3-foot door opening and compare it to the scale noted.

Mark floors, walls and ceilings with notation of type of construction -

Example of floors: raised computer floor, concrete or wood deck.

Example of walls: block walls, concrete walls or drywall stud walls.

Example of ceilings: drywall, tile or drop ceilings.

When you do your take-off, you will know what type of boxes to use, including floor boxes (either frame, block or concrete boxes).

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Number the pages on the plans - Before you take any blueprints apart, sequential number the plans (Use a magic marker and mark each page at the bottom right). Many architects and engineers use a coded plan numbering system that is not sequential. You cannot always determine if a plan sheet is missing once you have taken the plans apart by numbering in advance. You may even choose to note the page number of the blueprint on the take-off sheet in case you need to refer back to it when you are transferring information to your electrical estimating software. A plan sheet that is left out or missed can be a very costly mistake!