AEC definitions
A sheet index is the list of every sheet in a drawing set, by number and title. It is the table of contents, usually on the cover sheet. If a sheet is in the PDF and not in the index, or the reverse, the set is not the set it claims to be.
What you're looking at
Floor Plan, annotated
An architectural floor plan with walls, doors, room tags, and the column grid every other discipline draws on.
Definition
Reviewers, bidders, and plans examiners use the index to see whether they have a complete issue. Disciplines are grouped: general, civil, architectural, structural, mechanical, electrical, plumbing. Titles in the index must match the title blocks. When an addendum adds or voids a sheet, the index is revised in the same issue. A set with two indexes, from two different dates, is two sets.
In depth
Count the sheets against the index before you review or bid. Missing sheets are scope you have not seen. Extra sheets may be leftovers from a prior issue that contradict the current one.
Voided sheets should stay in the index with the word void, so nobody wonders whether sheet S-301 was never drawn or was removed. Deleting the row hides the history.
If the index says 'Level 1 floor plan' and the title block says 'First floor plan', references get sloppy and automated checks fail. Pick one and use it in both places.
The sheet number is the stricter key. A duplicate number, A-101 used twice, breaks every detail bubble that says A-101.
G for general, C for civil, A for architectural, S for structural, M, E, and P for MEP are common. The National CAD Standard and office standards vary. What matters on a project is that one system is used and the index follows it.
Consultant sheets that arrive under a different numbering scheme need to be reconciled before the combined set goes out. Two sheets named E-101 from two firms is a real event on large jobs. Renumber on purpose.
The index sheet has its own revision. When you issue an addendum, the index revision should describe the sheets added or reissued. A narrative that says 'replace sheet A-501' without an index update leaves the cover sheet lying.
Permit sets and construction sets can diverge. Label the index with the purpose, the same way the title block does, so a permit drawing list is not used as the construction list.
A BIM file contains views. The sheet index lists the views that were issued as sheets. Views that exist only in the model are not contract drawings. Do not let a view list in the software replace the issued index.
If the contract requires a model and drawings, say which sheets are the contract graphic. The index is that list.
Examples
The cover sheet lists 42 architectural sheets. The PDF contains 42, and each title matches. The bid set is complete as indexed.
Addendum 1 adds A-611 and marks S-102 revised. The index is reissued with both changes and its own revision note.
A plumbing sheet P-201 is in the model and not in the index or the PDF. It is not part of the issued set.
FAQ
