Help for a novice

by Dan
(Fresno, CA USA)

A question from a real novice.
I have a scale model railroad building drawing, which says it is drawn to HO scale, 1 foot=3.5mm. Assuming this is correct, I placed my scale ruler on the drawings to verify the dimensions, however the measurements do not equate with the scale ruler.

Do these measurements on the drawing have to be reduced to be actual HO scale?

< b> I have never run into this and I use my metal scale ruler incessantly in all scales and have found it accurate

I have also found that Drawings, by in large are accurate.

A way to double check your measurements is to measure again in HO scale feet. Each actual inch equals 7'3" (seven-and-a-quarter inches).