Front door with sidelights

I'm drawing plans for a remodel. How big should I make the rough-in for a 36" front door with either one or two 12" sidelight(s)? I have 8' ceilings.

Thanks in advance,
Sharon

The rough for a 3/0 door would be about 38"; but the rough for your sidelights depends on what you order. If you order a unit ...door with sidelights...and install appropriate jack studs and header, that would be one thing. If the sidelights are independent, the studs and headers would be different

You should be able to get some spec sheets and some recommendations at the millwork desk at your local lumber yard.