Measurements not adding up - room divider issue?

[nematode]

I'm using HDS on a Win10 machine. For some reason, it appears HDS is undercounting the length of a space by about 6.5". It might be relevant that I have two room dividers of 0" thickness. I've done some searching on this issue and found a thread on a similar problem but the trigger appears to be uneven floors/ceilings which doesn't apply to my file. I have the dimension defaults set to "surface" and "both wall sides".

 

Here's a Screenshot if it helps in which I show the discrepancy between actual vs calculated measurements.

 

Any ideas on what's going on?

 

Thanks,

N

 

[davidstvz]

Where are you getting the "actual" measurements?  Are you getting that from summing up the individual measurements along the outside wall?  If that's the case, you can see why there's a discrepancy.  The last measures at the outside walls include the exterior walls, while the inside measurements you show don't include it.  Also the series of measures you show along the outside don't include 3 interior walls.

 

The space marked 287 1/2" is accurate which you can observe by counting the grid spaces.