Room Boundaries - number lines

I read the perimeter of 11 rooms:

no.3 room has 6 sides —> I find 8 lines ----> why? —> How to find the Boundaries lines?
nr.1 room has four sides —> I find 6 lines ----> why? —> How to find the Boundariesr lines?

I enclose img

You should highlight your edges one by one to check what is going on, like so:

Hi @alex_volt

You should upload your rvt file so that we can have closer look at it.

You’re getting multiple curves due to the nature of your wall joins and an other wall which touches that space. You should look at this post for a possible solution and also read @Konrad_K_Sobon explanation which is more detailed than mine:

Thanks for collaboration
I solved this way:
I transform the rooms in solid -----> I find the perimeter