Site Imbalance

I'm an owner/builder who bought Kubla Cubed to help with determining the site imbalance of my home build.  I was hoping I could use it to minimize the back and forth with the site plan engineer and my excavator.  The issue I'm having is that the Net volume I'm getting with Kubla Cubed is significantly different then what my excavator is coming up with in his calculation.  I tend to believe him since he has been doing it for 25+ years and he was spot on for another project he did for me.

I've attached the kubla file for this project.  I'm trying to eliminate the porches and garage from the fill imbalance since I will need to fill with gravel to avoid compaction of any soil in those areas.  So I'm really only looking at the cut of the basement and the grading as my points for determining the imbalance.

He is coming up with around 1000 cu yds of fill.  I'm coming up with about 200 cu yds of extra fill.    Interestingly enough if I move the features in the proposed grading down to the bottom, then I show a 1,000 cu yd fill imbalance.

Any ideas as to what I'm doing wrong?

Thanks,
Mike

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I'm having some difficulty attaching the Kubla Project file.

Like for KSP file: https://drive.google.com/open?id=1_cgBjX...SnzXInNj9W