Drawing a scale from inserted building survey...what commands?

I've not used AutoCad for probably 15 years. I used it in my government job, but have forgotten many commands. I have inserted a building survey into a new DWG, and remember that I can find a dimension on that survey, and use it to begin a scale for the drawing, so that I may make additions to the building drawing. Can anyone remind my feeble mind as to how to do that? Thanks!

The general idea is to draw in model space to actual size, i.e. without a scale. Then you create a viewport (or viewports) in paper space to the scale (or scales) you need.

If your building survey is not the right size, scale it up/down so that it is.

So taking measurements off of the building survey/plat and using them for dimensions would work? If I find a wall that is say 10' in length, could I not scale out additions to the house in 10 feet increments? I seem to remember doing an actual scale off of a block or property plat that was inserted into the new drawing? Am I making sense here? Is there a command for creating a scale on a drawing, if say the scale is 1" = 20'?

One reason for drawing the model at the actual scale is so that you don't have to convert measurements every time you need a number. If the wall is 10 feet long, you draw a line that is 10 units long. Doing it another way just makes it more complicated than it has to be. If you worked for the government, though, I guess you got used to that:).

Once you have the model, you create a viewport to handle scale. A viewport at 1"=20', for example, will print that 10' line at 1/2". If you need a 10' scale sketch, you create another viewport instead of another model.