I tried to fit a Water distiller in a space which was only just large enough.
On the RHS a gas vent and on the LHS a coal generator, tile floor.
On selecting the water distiller to build the outline was white and it built OK if placed.
If I pressed O to reverse the connections horizontally the building outline showed red and the building shifted to the left relative to the mouse cursor. It would place a white outline if clicked, but the white outline would not build and showed unable to build error text, in the exact same location that the non reversed building did build, see screeny.
Screamshot of location.
Refusal to build could be rectified at placement by previously adding a build-on-able tile on the RHS, effectively requiring 5 spaces instead of four, which is just greedy. Note bulb is on other side showing reversed building.
attempt to place water distiller reversed in a space only just large enough to build it, reversed building will not place unless there is an extra buildable space on the RHS