What does INSUNITS control?
Autodesk's AutoCAD 2026 documentation describes INSUNITS as controlling automatic scaling when blocks, images or xrefs are inserted or attached. Its listed values include millimeters and meters, as well as unspecified units. It also notes that INSUNITS is ignored for annotative blocks.
DWG Conversion is independent and is not affiliated with Autodesk. Check the documentation for the installed product and distinguish an xref from a block or underlay before applying a check. This page reviews evidence; it does not prescribe a repair command for every drawing.
What belongs in the scale verification worksheet?
Keep a controlled copy of both source and host files. Choose a known dimension supported by the issued design, rather than estimating size from a screenshot or the apparent symbol height.
| Check | Record | Acceptance evidence |
|---|---|---|
| Source identity | Filename, drawing revision and reference status | Correct issued reference is loaded |
| Source units | Declared units and known geometry basis | Units agree with the checked dimension |
| Host units | Declared units of the receiving drawing | Host basis is recorded |
| Insertion state | Observed scale and transform in the host | Any non-unit factor is explained |
| Known dimension | Expected value, unit and source reference | Measured geometry agrees after unit conversion |
| Exception | Mismatch, unresolved basis or intentional transform | Authorized owner records the disposition |
| Recheck | Corrected delivery revision and checked dimension | The final delivered copy passes the same check |
How can a known dimension expose the problem?
Illustrative example. A fictional source drawing uses millimeters and contains a verified 1000-millimeter span. The receiving drawing uses meters, so that span should represent 1 meter in the agreed host basis. A host measurement of 1000 meters exposes a unit or scaling mismatch. The conversion 1000 millimeters = 1 meter does not establish which setting caused the error.
Record the observed source basis, host basis, insertion factor and measurement. Ask the drawing owner to determine the correction. Do not repeatedly scale the reference by eye until it resembles the surrounding layout.
Recheck another agreed dimension and the relevant electrical interfaces after correction. A single checked span may miss an intentional non-uniform transform or a problem in a different reference. Keep the review scope explicit.
How should a correction be handed over?
Preserve the original files and explain the approved change in the delivery note. Record whether the source, host or attachment state changed, and which dimension was used to verify the result. Do not silently alter the source design to compensate for a receiving-file problem.
Review the delivered copy in the agreed recipient environment. Confirm that the reference identity, units and observed dimensions still match the worksheet. A saved setting alone is not evidence of the final geometry.
Keep plotting scale separate from model-space unit verification. The issued PDF is a useful comparison, but the CAD geometry must satisfy its own agreed basis. Engineering sign-off remains with the registered engineer on the job; the file check does not approve electrical design.
Common questions
What else should the bid team know?
Does a scale factor of 1 prove the units match?
No. Verify the source and host bases against a known dimension.
Can a screenshot establish the correct scale?
No. Use controlled geometry and an issued dimension reference.
Should a reference be rescaled by eye?
No. Record the mismatch and obtain an authorized correction with a repeatable dimension check.