Last month, I talked about the types of residential estimating methods with which I am familiar. However, there are more out there. During my research, I met several electricians who have created their own methods, including some sophisticated spreadsheets. There is nothing wrong with these, as long as they cover your costs, create profit and keep up with rising material prices and labor expenses.

Commercial electrical estimating

Commercial estimating includes strip malls, restaurants and office spaces. It runs the gamut from simple work, such as a tilt-up warehouse space, to the most complex, including hospitals with more than a dozen types of electrical systems, from nurse call to multiple emergency power systems capable of powering the entire building.

As a trainee estimator, my first projects were for commercial work. I bid on the aforementioned tilt-ups, as well as bank branches, tenant work, retail spaces and some work that bordered on industrial, such as a Fuji Film processing center. All these projects had one thing in common: there was only one method used to estimate them. My employers and instructors from the classes I took, including those from the National Electrical Contractors Association, taught me how do it. 

This is what I came to call the line-item method, which, in the simplest terms, consists of creating one line on a pricing sheet for each type and size of electrical material needed for the project. Each line includes, at a minimum, a price for the material and a labor unit that represents the time it takes to install it. Of course, the completion of an accurate electrical estimate is more complex than it seems. Let’s explore those complexities.

The graphic above shows the column names and one line of material. It also features a column for material discounts. I used a format like this one for my very first estimate and still use it today. I have used preprinted forms, computer spreadsheets and reports generated by estimating software. They all convey the same basic information. Some may have additional columns for other information, such as labor factors. The example above also has a column for material discounts.

First things first

Setting aside pricing sheets for a few minutes, let’s go over the first steps of a commercial estimate. The first thing I do after receiving a new project is study the plans for a little while. I am looking for the general scope, unusual items and notes. The notes are very important, as they supplement the specifications in areas such as adding scope, defining material requirements and calling out work shown in details on other pages. 

Unfortunately, notes can also contradict the specifications. If you run across contradictions, you may need to send a request for information to your general contractor, or whatever the proper channels are for this project. The sooner you familiarize yourself with the notes and specifications, the sooner you can get clarifying information.

Specs, specs and more specs

The specifications, then, are the next item I tackle. For smaller projects, the specifications are text you may find on one or several of the plan sheets. For most of the projects I bid, however, the specifications are in a separate document. 

At one time, the purpose of the specifications was to define the material required for a project. Manufacturer names, quality levels, catalog numbers and other requirements were all in the specifications, and the scope of work was always shown on the plans. Unfortunately, material requirements and scope are now mixed between the plans and specifications. I have a separate section in my bid notes to record scope that appears in the specifications. 

For every project I bid, I prepare a specification review. This is very important, as the differences between projects can start to blur when you are bidding many concurrently or close together. My specification review includes many types of information, including quotations I will need, questions I have, exclusions and qualifications, information on addendums, separate bid items required for the project and, of course, material requirements (the original reason for the specification review). 

For the latter, I am looking for information such as types of boxes, wiring devices, conduit and wire types, and testing requirements, plus specific requirements for quotations such as lighting fixtures, switchgear manufacturers and low-voltage systems (e.g., fire alarm and security). This document will evolve during the estimate as I receive new information, such as the answers to my RFIs and commitments from the quotation requests I sent. 

Stephen Carr