Rotating buildings before placement

[Cor.]

I know how to rotate buildings by dragging to the direction you want before you place.

But, you cant do that if the building is red/orange. How I found how to nestle them in as tight as possible, all facing the right way.

Usually you have a command center placed already. Take the building, which is off kilter to the CS and get it as close as you can to a corner, keeping it green.

Once its as close as it is, drag rotate to the direction you want, it should go red/orange.

You can then place it snuggled right up to the building you want. It will stay in the direction you want it.

Took me a long while to figure this out.