Before beginning a new drawing it is essential to determine how the page should be set up, thus ensuring maximum output and accuracy. You should have already determined what scale and unit’s best fit your design and these can be edited under:
File>Document Settings>Document Setup> Drawing Units
And,
File>Document Settings>Document Setup> Layer Scale
When changing Unit(s) settings it is important to make sure that all units (length, area and volume) are proportional. These units can however be edited at any given time with immediate effect.
The Layer Scale command lets you change the drawings scale, and can be edited at any given time with emmediate effect. It is recommended that you change the scale to a more suitable and presentational one as the default scale is set at '1:1'.