This build plans a building around two telescopes instead of one. Each stands on its own pier with its own position, mount height, mount type and optics. Everything lives in one place: open Step 5, Pier layout, switch on Telescope 2, and it gets a pier of its own on the floor plan in that same step. Click inside the building outline to place a pier, drag it to move it. For each telescope the step reports the swing clearance to the nearest wall, the floor and the parked roof; for each pair, whether their swept volumes clear by the walkway gap you set. The pointing checks and the sky sweep run for whichever telescope you choose, from the Pointing telescope selector under the 3D view.
Telescope 1 is still placed by the wall measurements in Step 1, so nothing about the way you describe a single-telescope building changes. Setups saved here load in the released calculator and the other way about; a second telescope is simply ignored by the build that cannot show it.