A Look at Residential Plumbing Estimating

By:  Cyd Oldham           


In the construction field, estimating is a learned skill which is an essential part of every job.  Plumbing jobs are no different, and the ability to perform and accurate estimate or “takeoff” is elemental to the growth and stability of the plumbing company.


While a high estimate may not win the job, underestimating will lose money.  It can be a fine line to walk.  Either way, presenting a professional looking bid will leave a winning impression.  


Be sure to type your bid, or print it from your computer, and include your contact information, credentials, and license and insurance information on the form.  Leave room for acceptance signatures right on the estimate.  Also, it is a good idea to put an expiration date on the estimate because of cost fluctuations and scheduling.


Estimating software is now available to help you prepare your estimates.  These programs, such as Takeoff Live, allow you to upload the plans into your computer, then do the take offs and calculations automatically.  Takeoff software not only saves time, it increases accuracy and decreases headaches. 


When preparing your estimate, it might be a good idea to visit the job site in order to clarify specific details, being sure to take measurements while at the site.  This visit is important to be sure the client has not left out some important element which may cost you money in the end.


Estimate the number of employees you will need on the job and length of time the job will take to complete.  Don’t forget to figure in expenses such as driving time to and from the job.


While you’re thinking about driving time, think your overall business overhead relating   to the job.  Many contractors fail to consider these costs when estimating jobs, thus losing money.  Overhead includes costs such as insurance, licensing fees, utilities, payroll, and sales tax.  Overhead should be calculated on the total job estimate.


Now it’s time to decide how much you would like to profit on this job.  A 20-25 percent profit margin is used by many plumbing contractors.  Add your overhead to the costs, including payroll, then multiply the total by the profit margin to get your plumbing estimate.





Be sure to review all documents before completing your plumbing estimate.





Sometimes items are in the specifications but not on the drawings, or on the plans, but not in the specifications.




Read all communications from the owner.



They may have requested changes or have certain needs which haven’t been included in the specifications or drawings.




Make sure the drawing scales are the same when using drawings from different sections of the plans.



You wouldn’t want to end up with twice as much pipe as you need (or half – a nightmare) because you didn’t realize the drawing scales varied from mechanical to structural.




Don’t forget to include items which are not on the plans which must be priced.



These may include temporary water supply, cleaning piping, purifying potable water systems, and cleanup.



Remember that your memory can become log jammed when you’re busy, so document everything.  All discrepancies from standard practices, omissions, or other concerns should be dealt with before finalizing your estimate.