What is MasterFormat?
MasterFormat is the standard for organizing construction specifications in North America, published by the Construction Specifications Institute (CSI) and Construction Specifications Canada (CSC). It gives every topic in a project manual a fixed number and title, so architects, engineers, contractors and suppliers can find the same requirement in the same place on every project.
The same numbers show up outside the project manual: drawing keynotes, submittal logs, cost estimates and bid packages are often organized by MasterFormat section. That shared numbering is what makes spec QA possible to systematize, and why a wrong number propagates so easily.
How the divisions are organized
The current structure has 50 divisions (00 to 49), grouped into the Procurement and Contracting Requirements Group and the Specifications Group. The divisions most building projects use:
| Subgroup | Divisions | Examples |
|---|---|---|
| Procurement and contracting | 00 | Bid forms, agreements, conditions of the contract |
| General requirements | 01 | Submittal procedures, quality requirements, closeout |
| Facility construction | 02 to 19 | 03 Concrete, 04 Masonry, 05 Metals, 07 Thermal and Moisture Protection, 08 Openings, 09 Finishes |
| Facility services | 20 to 29 | 21 Fire Suppression, 22 Plumbing, 23 HVAC, 26 Electrical, 28 Electronic Safety and Security |
| Site and infrastructure | 30 to 39 | 31 Earthwork, 32 Exterior Improvements, 33 Utilities |
| Process equipment | 40 to 49 | Process integration, material processing equipment |
16 vs 50 divisions
Inside a spec section
Section numbers are six digits in three pairs: division, level 2 and level 3. 09 29 00 is Gypsum Board within Division 09 Finishes. Under CSI SectionFormat each section has three parts:
- 1Part 1 General: scope, related sections, references, submittals, quality assurance, warranty.
- 2Part 2 Products: materials, manufacturers, performance requirements, fabrication.
- 3Part 3 Execution: examination, preparation, installation, field quality control.
Most spec-to-drawing conflicts live in Part 2. A product, rating or size in Part 2 that does not match what the drawings show is the classic bid-day RFI.
Common spec errors
Inside the project manual
- Dead cross-references: "Related sections" pointing to sections that were deleted or renumbered.
- Master spec leftovers: unedited bracketed options, another project's name, products the project does not use.
- Outdated references: standards or code editions that do not match the project's adopted code.
- Division 00 vs 01 conflicts: submittal, warranty or closeout terms that differ between the contract and the general requirements.
- Scope gaps between trades: "provided under Division 26" when Division 26 never mentions it.
Between the specs and the drawings
- Product mismatches: the spec calls for one material or system, the drawings show another.
- Ratings and performance: fire ratings, STC values or wind loads that differ between Part 2 and the drawing notes.
- Schedules vs specs: door hardware, finishes or equipment in the schedules that the spec sections do not cover.
- Keynotes to nowhere: drawing keynotes citing section numbers that are not in the project manual.
- Orphan sections: work specified in the manual that appears nowhere on the drawings.
Spec QA checklist
- Table of contents matches the sections actually included
- Every "related sections" reference resolves to an included section
- No bracketed options, editor's notes or other projects' names remain
- Referenced standards and code editions match the adopted code
- Every drawing keynote section number exists in the manual
- Products and ratings in Part 2 match the drawings and schedules
- Each scope item handed between divisions is picked up on the other side
- Submittal requirements in Part 1 match Division 01 procedures
Automating spec vs drawing checks
The checklist above is simple to state and slow to do by hand: a 600-page project manual against a 200-sheet set means thousands of cross-references. That is the part software handles well.
InspectMind reads the project manual and the drawing set together and reports where they disagree, each finding with the sheet and section reference so a reviewer can confirm or dismiss it. It also checks building code compliance and submittals against the specs. Checks are self-serve from $50, with a 5+ issues or full refund guarantee.
Check your specs against your drawings
Upload the project manual and drawing set. Cited findings in hours.
- $100 first-check credit
- Results in hours
- 5+ issues or refund
5+ issues or full refund · No demo required
Frequently asked questions
How many divisions are in CSI MasterFormat?
What do MasterFormat section numbers mean?
What are the three parts of a spec section?
If the specs and drawings conflict, which one governs?
Can AI check specifications against drawings?
Related resources
- Use caseSpec vs Drawing CheckerFind contradictions between your project manual and drawing set, with cited findings.
- Use caseSubmittal Review CheckerCheck submittal packages against the specifications before approval.
- GuideCopy-paste spec errorsHow reused master specs create project conflicts.
- GuideSchedules vs specsCatching material mismatches between door, window and finish schedules and the specs.