Reference coordinates on a site plan refer to distances from what?

Reference coordinates on a site plan refer to distances from what?

• A. A pre-determined datum or benchmark
• B. Geographic north
• C. The equator
• D. A local street reference

Answer: (A)

Coordinates on a site plan are measured from a fixed origin defined by a datum or benchmark. This establishes a known starting point so every horizontal distance (X and Y) has a consistent meaning throughout the drawing set. The datum ties the plan to the real world and makes measurements reproducible across different pages and trades. Directions like geographic north or global references such as the equator are about orientation or global position, not the local origin used for plan coordinates. A local street reference might help locate the project visually but isn’t a fixed, universal origin for accurate measurements.