Confirm Units and Reference Before Combining Two Site Records
Two accurate-looking site records may still use different units, origins or elevation references. Before combining them in a coordination document, ask how their values relate. A clean overlay on a screen is not enough to establish that the underlying records are compatible.
Identify each record independently
Keep the source name, version, collection date and intended purpose with each file. Ask which units and reference conventions the producer actually used; do not infer them from a file extension or a familiar-looking number. Distinguish a relative room measurement from a value tied to an identified site reference. Missing metadata should remain missing until its source confirms it.
Assign the compatibility check
Identify who is qualified and authorized to decide whether a transformation or additional verification is required. State which decision depends on the combined view, such as coordination, a clearance check or a comparison of observations. Do not silently convert units, shift an origin or add apparent precision just to make two images align. Record any transformation with its assumptions and responsible reviewer.
Preserve originals and the limit of the result
Retain the unmodified source records alongside the reviewed coordination copy. Make the copy’s purpose and limitations clear to recipients who did not attend the discussion. A general site record does not become a legal boundary survey or an engineering certification through file conversion. If compatibility cannot be established, keep the records separate and identify the additional information needed before relying on a combined dimension.
Copyable worksheet
Use one row for each field. Mark unknown information clearly and retain the original records.
| Field | Your note |
|---|---|
| Source versions and intended uses | ____________________ |
| Units explicitly confirmed | ____________________ |
| Origin and elevation references | ____________________ |
| Compatibility reviewer and assumptions | ____________________ |
| Decision permitted by the combined copy | ____________________ |
Worked example
Illustrative example: a fictional team receives one room record in feet and another with an unidentified coordinate reference. Rather than resizing them until they appear to match, it asks the producers for the missing conventions. The coordination drawing stays provisional while the original files remain intact.