How does TBC Takeoff Handle Overlapping Site Improvement Areas

This question came up today and I thought it was worth capturing a simple example.

The question was how does TBC handle overlapping site improvement areas. i.e. I have multiple polygonal areas for e.g. Pavement that in some areas overlap. The question is really how do you want the overlap areas handled i.e.

  1. Do you want the overlapping areas double counted for some reason?
  2. Do you want to only count the overlapping areas 1x?
  3. Do you not want the overlapping area included in one or other of the two conflicting areas or do you want them counted as an overlap area and reported separately?

The answer to the above questions will dictate how you set up your linework to do the computations.

TBC will not double count overlapping areas - the area of overlap will be identified as a stand alone region separate from the remaining areas of the original polygons, i.e. where you would normally just have 2 areas you now have 3 areas because of the overlap zone. When you assign the site improvements, if you don’t change the linework, you will assign a Site Improvement to each of the 3 areas and that will give you 3 line items in the report - one for each area.

If you want to report the entire area as one pavement area in the reports then you need to edit the linework or use commands like Track Region to find the bounding areas that you want to use and eliminate the overlap zones in the process. If you do this then the areas that you define will become the reported areas on the report.

The following video uses a simple canned example to explain how the overlapping areas can be addressed and reported.

The follow on question was then if I have multiple phases as well, how does TBC report out by phase.

The phase area boundaries split the Site Improvement Quantities into sub areas now controlled by the phase boundaries. In the video below we show how the total areas and material volumes are separated into 3 phases based on 3 non overlapping phase boundaries.

Hope that the videos help