Question
Can I use On-Screen Takeoff for sitework (Cut and Fill)?
Answer
Yes!
You can use On-Screen Takeoff to determine quantities of earth when prepping a site. The instructions below provide you with options for rough and detailed estimates on the amount of dirt you will need (or need to remove) from a site.
Rough Estimate
The fastest way of getting a 'down and dirty' (pun intended) estimate is to Overlay the original (existing grade) site plan against the constructed (finished grade) site plan - then setup Area Conditions for average variances of 1', 2', 3', 5', 10' feet. You will not get as precise of numbers, but you will get a 'good enough' estimate this way. If you need detailed numbers, follow the instructions below. You will use those Conditions to take off where the height varies by the value closest to your Conditions. You will set 'fill' areas as 'negative takeoff' and 'cut' areas as positive takeoff.
Detailed Estimate
First you should load in the plans that show the contour lines of the site, as well as a footprint of the object that will need to be leveled. You will find that you will need to make a comparison between the original contour of the site to the finished contour of the site. Here you will look at a parking lot area that will need to be leveled. Notice the contour lines indicating the finished grade of the ground. You can create an area condition for each level of elevation and takeoff each elevation.
Once you have created your Conditions, start doing takeoff for the area.
You now have the takeoff for the final grade of the parking lot. However, you will need to compare this to the original grade of site. If the plans are the same scale, you could use the Overlay feature to compare the original to the finished grade. However, the original plan is a smaller scale than this plan. Instead you will outline the area, then copy and paste the outline from this plan to the other plan which is a different scale.
Make sure you have set your scale before pasting in the outline.
Now you can continue the takeoff process on this original plan in the same manner as before, creating conditions with no thickness, until you have completely filled this outline.
It's a good idea to create two folders that will show the takeoff information. This way one folder will hold the original grade conditions, and the other folder will hold the finished grade conditions.
Once you have completed takeoff on both plans, now you need to be able to compare them. You need a benchmark to compare both sets of plans against each other. Since the lowest grade on both plans is at 660 ft, let us use that as our benchmark.
Open each condition, and add in the thickness in one foot increments. So the condition listed as 661 ft will have a thickness of 1'0”, 662 ft would have the thickness listed as 2'0”, and so on.
In this example, you will see that in the original plan, it is lower than our benchmark of 660 ft. It reads 659 ft. You should go ahead and add the thickness as 1 ft. Then select the takeoff, and right click to make it negative. The advantage to doing this is you will graphically show those numbers to be negative, thus showing where it needs to be filled.
Now on the Takeoff Tab you will notice both positive and negative numbers. When you export this to an Excel spreadsheet and add the column up, you will see if you need to bring in extra fill, or if you need to haul off extra fill.
If you do not need the quantity of square footage, you may change Quantity 1 to volume and have your totals listed there.
Once takeoff quantities are in Excel, compare the two amounts of finished grade versus original grade to indicate if you need to bring in fill, or how much you will need to remove.