How to Estimate Electrical Work

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Electricians are responsible for installing wiring, lighting, power outlets, and other electrical components in homes and businesses. Before an electrician is hired, he or she will generally prepare an estimate, which indicates how much the project will cost to complete. An electrical estimate represents the total costs for materials, labor, overhead, and profit, and is usually accompanied by a list of the work included in the price. Because of the complexity of electrical systems, some basic knowledge and experience in this field is needed to prepare an accurate estimate.

Start by reviewing the entire set of building plans before you begin. Electrical drawings are often crowded with symbols and wiring information. By viewing the architectural plans first, you will gain a better understanding of the intended function of the space. This will allow you to create a more accurate estimate.

Review the electrical plans. Perform a material take-off for each electrical system. This involves counting the amount and type of each material needed. With the building power, for example, you'll need to count the number and type of electrical panels, number of breakers, lengths of wiring and conduit, and number and location of power outlets. Send these quantities to your various material suppliers to obtain unit pricing. Repeat this process for all systems, including lighting, mechanical connections, and any other work applicable to the job.

Calculate labor costs. Determine how many hours you'll need to perform each type of installation, then multiply this number by the average wage of your employees. Include supervision, technicians, and laborers as needed.

Determine if there are any outdoor or underground electrical tasks on the job. This work may be shown on the civil plans or landscaping drawings, and is easy to miss when you're used to working off of the electrical plans. Look for electrical service expansion requirements and outdoor lighting, and add the cost for this work to your price.

Request pricing from subcontractors for any specialty work. This includes temperature controls, fire alarm, and communication systems. Send a copy of the relevant drawings and specifications to these companies, making sure to get pricing for any work you don't plan to perform using your own staff.

Include costs for electrical permits. Permit fees are based on the number of breakers or circuits being added to the job. On larger projects, this can add thousands of dollars to the cost of the project. Use permit rates in your city or county to calculate this cost.

Read the General Conditions in the Specifications Book and in the Bidding Instructions, if applicable. These often contain information that can greatly effect your price. Look for information on scale wages, night work, work in occupied spaces, and bond premiums or requirements. Include the cost of these items in your price.

Prepare your estimate. Include all costs you calculated in Steps 1 through 7, as well as a fee or percentage for overhead and profit. Specify on your estimate what work is included or excluded, and indicate whether sales tax is included in your numbers.


Check your work. Divide your total estimated price by the number of total square feet in the job. Compare this cost per square foot to that of similar jobs you've done in the past. This test will often let you know if you've made a major estimating error.