If section planes don't do it for you, you can always fall back on layers. The only reason for layers in SU is to control visibility...not to separate geometry...so that is pretty much what you want.
You need to draw everything on Layer0 then move it to other layers you create...preferably after grouping it first. The only reason I haven't grouped stuff in my example file is that the house is only 1 skin thick so you'd see the edge of the groups all over the outside walls...very messy.
You can see in the example that you can reveal whatever you like by hiding the appropriate layers. Different requirements would obviously call for a different layer structure.
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