Estimating in the 21st Century

When I learned to estimate we had printed estimate sheets which had all the fittings listed in a column and I would go over the drawings making little marks, in groups of five, beside each fitting. Then I would count up all the pieces of pipe. Hub pipe has to be counted in 10', 5', and 30” lengths – single hubs and double hubs. Next I added up all of the marks, extended the fitting and pipe prices to find my material cost.

After that came hangers, pounds of lead, rolls of solder, tanks of gas, etc. until all the material was accounted for. Labor required a little experience as to how long things take men to do – everything from digging trenches to pouring joints to setting fixtures. But everything was done on paper and calculations were done on an old adding machine. We stapled the tape from the adding machine to the quote when we were done in case we needed to go back and check something.

Today everything is electronics and spread sheets. That's not a bad thing. We do take-offs from .pdf drawings, enter quantities into spread sheets and automate as much as we can. On a spread sheet you can include labor in a column right beside material cost and Excel will calculate both when you enter a quantity of fittings or pipe. I even have equations that pull the pipe and fitting quantities from one sheet and calculate the hangers and no-hub couplings I need on another sheet. Same with copper pipe and fittings extending to flux, solder, and mapp gas.

Saving steps saves time and increases accuracy. If I'm tallying pipe on one sheet and then jumping to another sheet to tally couplings and another to tally hangers, I could get in a hurry and miss something. The spread sheet does it automatically and doesn't miss a thing – as long as your macros are set up right. I add a fitting and it adds solder and flux and sand cloth and the labor it takes to make the joint! Everything is fast, efficient, and accurate.

Now as we move into Revit we have tools to cut those steps even more. In Revit we can throw out the process of counting all together. Revit schedules are basic spread sheets. You probably already use them as schedules on your drawings – listing the pipe, fittings, equipment and fixtures. You may even go to your Revit schedules to get your take-off numbers to plug into your estimating spread sheet. But why are you using two spread sheets? Remember, schedules in Revit are just spread sheets you fill with data from families.

Revit schedules have all the basic functions of Excel spread sheets. You can export them as spread sheets. You can print them as spread sheets. And you can apply calculations and formatting JUST LIKE EXCEL SPREAD SHEETS. Now let that sink in.... I can set up my schedule to bring in material and quantities. I can add calcs to the schedule to use those quantities in equations. Now, if my families and calcs are right, when I draw a copper tee Revit adds solder, flux, sand cloth, and labor to the schedule in correct quantities. Revit does my material takeoff as I design and if I delete that tee, Revit adjusts everything!

You can take that to the logical conclusion. If I set my “Estimate Schedule” up like my estimate spreadsheet – with labor burden, overhead, profit, etc – the estimate does itself as I design. When the model is complete, the estimate is complete, and if I make changes – the estimate updates. If I'm given a finished model all I do is create my estimate schedule and I'm done. The estimate fills itself in! If I make changes during coordination, I can compare the new estimate against the old and know exactly what dollar figure that change represents. Instantly!

Disclaimer. As I've said over and over – the model must be an accurate representation of what will be built in the field. If a designer stuck a sanitary tee where there should be a combination, Revit will count a sanitary tee in the estimate. Revit is just a dumb program. You need to survey the model for accuracy and code compliance before you just export a quote. You'll also need to make sure nothing is being missed, like a boiler with a screw-up in the family that keeps it from being listed in the schedule. We're not to the point of AI plumbers yet, so get a plumber to sign off on the model. Better yet, as I've said before You Need a Plumber designing your model in the first place!