Dimensioning
How to dimension in landscape documentation
Why do we dimension?
Dimensions are used to accurately communicate the size, and location of objects, spaces, and components within drawings. Drawings are generally made to scale and can be checked with a scale ruler; however, this does not provide high enough accuracy for smaller elements and leaves room for human error.
Often elements within the landscape have minimum and maximum sizes that they need to fit with to meet regulations making dimensioning critical. An example of this is in children’s spaces specifying gap sizes to limit chances of entrapment.
When no dimensions or a scale bar are included on a drawing it quite hard to check whether the drawings scale is still accurate and hasn’t been modified in the printing process or similar.
Principles of dimensioning
Principles
Like in most aspects of life rules work except for when they don’t so you will need to use discretion as to when to break the rules to meet your objective of clearly communicating the sizes and locations of objects and spaces.
Clarity - Dimensions must be clearly displayed with an obvious relationship between the dimension lines and the element within the drawing it is denoting. That said, it is usually clearer when dimension lines do not run directly into the element they are annotating.
Consistency - The same techniques should be repeated when dimensioning.
Accuracy - Often designers will write in the fine print that dimensions will over-ride scale drawings. Meaning that they should be followed and need to be accurate.
Group and align - Where possible you should group and align your dimensions to help visually separate them from your drawing and keep your drawing orderly.
Avoid duplication - In general we try to say things once and in one spot only to avoid conflicts, reduce clutter and avoid extra future editing. If you dimension one side of an object and the other is clearly the same, then there is no need to dimension both.
Less is more - Avoid putting in more dimensions than are necessary to communicate your intent.
Avoid Crossing of Lines and text - Lines should not cross over each other including leader lines from annotations. It is very hard to follow and adds to the visual clutter.
Radius vs Diameter - Commonly circles have a the diameter dimensioned while arcs have the radius dimensioned.
How to dimension
There are different styles of dimensioning that differ around the world and between industries. Moreso than sticking to one standard I think the test is that if the average person within the industry could pick up your drawings and understand your dimensioning immediately than you have prepare them well.
Separation
Keep separation between subject and dimension lines
Angles
Whatever it is, the way you tell your story online can make all the difference.
Session Outline
Why dimension
Principles of dimensioing
How to dimension