It really depends.
Is your goal to recreate an exact scale model? Then you need to do some work as suggested above. Take a known value (or educated guess) of something clearly visible in the picture, like the rollup door, or person-door and extrapolate. THe side view is almost square on, so it should be pretty easy for that. The front view is not as good, but you will have the height and window measurements from the side to help.
If you want simply to make a building that looks like this one, then some selective compression is allowable. You can make it as big as it needs to be to fit the available space. For example, you could have three columns of windows on the side, instead of 4. Or cut off the entire right end from the front view. The resulting building will still have the same "flavour", but it will not be an exact replica.
Andrew