not sure this is a question about the tool so much as about the strategy. Imaging you're the framer on site who will have to deal with the 1/8ths of an inch you buried in imprecise dimensions. Rationalize the building via the model.
don't despair - read the Shoegnome blog post published last week.
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Congratulations on your 1000th post ! I'm still working on 500.
Gerald "The simplification of anything is always sensational" GKC AC 25-3011 USA, CadImage Tools 2019 MacBook Pro 16" w/ AMD Radeon Pro 5600M GPU OS X 11.6 2.4 Ghz 8 core i9, 64 GB RAM 27" LG 5K Monitor
If both dimensions said 2' 1/2" the overall dimension would not add up to the same as both dimensions reading 2' 1/4" at the higher accuracy. So I guess Archicad is making sure the overall dimension string is showing the correct total.
Personally, I would show the outer dimensions as "Equal"
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The level of precision the dimensions are displayed at is not only for the sake of the Carpenter.
It is also for the sake of verifying the precision and accuracy of the computer model, checking dimension chains, finding small differences in the schedules.
Dimensions on a plan are also not entirely for the sake of measurements.
For example, the reason to show a wall height dimension of 8'-1 1/8" is because this is how the carpenter knows you are indicating 92 5/8" studs.
I could list many other examples but you get the point I am sure.
A piece of solid sawn lumber has nominal size, an actual size, and a theoretical size.
We use the theoretical size in making the Plans with a computer.
This is why it is very important for both the builder and the CAD Technician to understand why things are dimensioned the way they are.
Partly for the sake of the computer, and partly for the sake of the carpenter.