Locate the project legend
Start with the legend, schedule headings and notes for the drawing issue you are reviewing. Record whether a tag refers to one physical opening or a shared type. The same-looking tag can play different roles in different drawing sets.
A letter such as W is not enough to establish dimensions, operation or a product specification. Follow its reference to the relevant schedule row and detail. A missing legend is a missing source, not permission to substitute a convention from another project.
| Notation | Meaning here | Do not infer |
|---|---|---|
| W01 / W02 / W03 | Unique physical opening marks | Universal numbering rules |
| T01 / T02 | Shared specification types | Quantity from the number of type rows |
| Operation: unknown | Operation not established by the example | Fixed or operable merely from a rectangle |
Connect marks across views
Follow one mark through the plan, elevation and schedule before counting it. Our original teaching fixture has W01 and W02 sharing T01, while W03 uses T02. That gives three physical openings and two types.
A mark seen again in another view describes another observation of the same opening when its location and context agree. Conversely, different marks sharing a type still describe separate occurrences. Read the complete schedule example for the associated quantity and dimension fields.
This three-opening diagram is separate from both the six-page synthetic house PDF and the editable house demo. Keeping those examples distinct prevents their counts from being combined accidentally.
Identify operation and view direction
Read operation graphics using the stated project convention. Look for the relevant opening description, hinge or pivot information, sliding direction and whether the view is from inside or outside. A facade drawing and an interior view can reverse the apparent left and right positions.
Keep handing abbreviations such as LH or RH with their source definition. If the convention is absent, ask the designer or supplier to confirm it. Geometry alone does not prove the intended opening operation.
In the original synthetic six-sheet PDF, W01-W06 are listed as windows with unknown operation and unspecified subdivisions. D01 is an entrance door and SD01 is a sliding door. That source supports those categories, but it does not resolve the windows' operation.
Record ambiguity for review
Keep the mark, source sheet, uncertain attribute and clarification question together. For example: W03, elevation and schedule, operation unknown, confirm the intended operation and viewing convention. Assign the decision to the person responsible for the design or product selection.
Separate a source-supported type from a temporary model choice. A choice made to explore a visual alternative does not retroactively establish what the drawings specified. Use the AI takeoff review checklist to retain that distinction.
Before totaling the records, reconcile physical openings and repeated types. Resolve or flag identities first; summing an ambiguous list only makes an uncertain count appear precise.