Preliminary plans or multi-family building plans are commonly drawn at 1/8″ = 1′-0″
Details may be drawn at 1/2″ = 1′-0″ or 1″=1′-0″
The rest of the world uses the metric scale, where plans are generally drawn at 1:50 and preliminary study and multi-family building plans drawn at 1:100 and details at 1:20.