CSI MasterFormat list: the divisions estimators use.
MasterFormat, published by CSI and Construction Specifications Canada, is the standard way North American project specifications are organized. Knowing the division list lets you find your scope fast, read spec references on drawings, and organize your takeoff and proposal the way GCs level bids. CSI released MasterFormat 2026 with 2,185 new and 617 reorganized listings, so check which edition your project manual uses.
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- Full division list
- What changed in 2026
- Section numbering
- Organizing takeoffs
MasterFormat
MasterFormat is a numbering system for construction specifications and related information. It uses six-digit section numbers (for example, 09 29 00 Gypsum Board), grouped into divisions 00 through 49, some of which are reserved. Most commercial project manuals follow it, and many estimating databases, bid forms and cost reports use the same divisions.
MasterFormat divisions
| Division | Title |
|---|---|
| 00 | Procurement and Contracting Requirements |
| 01 | General Requirements |
| 02 | Existing Conditions |
| 03 | Concrete |
| 04 | Masonry |
| 05 | Metals |
| 06 | Wood, Plastics, and Composites |
| 07 | Thermal and Moisture Protection |
| 08 | Openings |
| 09 | Finishes |
| 10 | Specialties |
| 11 | Equipment |
| 12 | Furnishings |
| 13 | Special Construction |
| 14 | Conveying Equipment |
| 21 | Fire Suppression |
| 22 | Plumbing |
| 23 | Heating, Ventilating, and Air Conditioning (HVAC) |
| 25 | Integrated Automation |
| 26 | Electrical |
| 27 | Communications |
| 28 | Electronic Safety and Security |
| 31 | Earthwork |
| 32 | Exterior Improvements |
| 33 | Utilities |
| 34 | Transportation |
| 35 | Waterway and Marine Construction |
| 40 | Process Integration (CSI's 2026 page; earlier editions used "Process Interconnections") |
| 41 | Material Processing and Handling Equipment |
| 42 | Process Heating, Cooling, and Drying Equipment |
| 43 | Process Gas and Liquid Handling, Purification, and Storage Equipment |
| 44 | Pollution and Waste Control Equipment |
| 45 | Industry-Specific Manufacturing Equipment |
| 46 | Water and Wastewater Equipment |
| 48 | Electrical Power Generation |
Divisions not listed are reserved. Confirm section-level titles against the edition your project manual uses.
What changed
Per CSI, MasterFormat 2026 adds 2,185 new and 617 reorganized listings:
- Divisions 32 Exterior Improvements and 34 Transportation account for more than 80% of the structural changes: a large expansion of site and landscape systems and a restructuring of infrastructure classification.
- Divisions 28 Electronic Safety and Security and 31 Earthwork expanded noticeably.
- Divisions 01, 06, 09, 10 and 26 had maintenance updates, mainly title clarifications and small reorganizations.
- Divisions 02, 07, 27 and 40 stayed largely stable.
What it means for estimators: sitework, landscape, paving and transportation estimators should expect new or moved section numbers. If your cost codes map to MasterFormat sections, plan a mapping update, and keep the old mapping for projects specified under earlier editions.
How section numbers work
A section number has three pairs: division, then level-2 and level-3 classification. For example, 05 12 00 is Structural Steel Framing within Division 05 Metals, and 26 05 19 is Low-Voltage Electrical Power Conductors and Cables within Division 26. A spec reference on a drawing (e.g. "see 07 92 00") points to the section whose materials, performance and execution requirements affect price.
Where to look
| Trade | Main divisions | Also check |
|---|---|---|
| Structural steel / misc metals | 05 | 01; 09 (coatings); 07 (fireproofing) |
| Electrical | 26 | 27, 28, 01 |
| Painting | 09 (09 91 00 Painting, 09 96 00 High-Performance Coatings) | 05 (shop primer), 01 |
| Flooring | 09 (09 60 00 Flooring sections) | 03 (slab prep, moisture), 01 |
| Drywall and framing | 09 (09 21 16, 09 22 16, 09 29 00) | 07 (firestopping, insulation) |
| Concrete | 03 | 31, 32 |
| Plumbing / HVAC / fire protection | 22 / 23 / 21 | 25, 26 |
| Sitework | 31, 32, 33 | 34 (heavily revised in 2026) |
Section numbers are illustrative. Confirm them against your project manual.
Costs estimators miss
Division 01 General Requirements applies to every trade, and it's where many unpriced costs live: submittals and shop drawings, mockups, testing and inspection, temporary facilities, cleaning, waste management and recycling, closeout documents, warranties and training. Some projects require schedule reporting or cost-loaded schedules. Subcontractors should check whether these fall to them or stay with the GC, and write clarifications where the documents are silent. Keep a short Division 01 checklist with your takeoff: one line per requirement that costs money, with your assumption next to it.
A takeoff by division
Organize takeoff rows by division and section where it fits your trade, then by area or system. When the GC's bid form uses MasterFormat, your numbers map directly. When an addendum revises a spec section, you know which rows to revisit. Referencing sections in exclusions ("excludes 07 84 00 Firestopping") is precise.
MasterFormat vs. UniFormat
UniFormat organizes by building systems and elements (substructure, shell, interiors, services) and is often used for early conceptual estimates. MasterFormat organizes by work results and is used for detailed specifications and bids. Many estimates start in UniFormat during design and move to MasterFormat for bidding.
Where RenderDraw fits: the counting, with your review.
Speed is easy to promise. Defensible numbers are the job, so RenderDraw keeps the estimator in control of every quantity that gets priced.
- Source on every row. Each quantity keeps its source sheet, location and reviewer decision.
- Lowest confidence first. The review queue shows the drawing tile with the detection highlighted and the extracted value.
- Uncertain items flagged, not hidden. Anything the AI can't confirm goes to the estimator rather than being guessed.
- Nothing priced before approval. Rows move on to pricing only after they are accepted.
Questions estimators ask.
What is the CSI MasterFormat list?
The standard list of specification divisions, 00 through 49, used to organize construction documents in North America.
What is the current edition of MasterFormat?
MasterFormat 2026, which CSI says adds 2,185 new and 617 reorganized listings. Most of the changes are in Divisions 32 and 34.
How many divisions are in MasterFormat?
The numbering runs 00–49, and several numbers are reserved.
What division is electrical?
Division 26, with communications in 27 and electronic safety and security in 28.
What division is structural steel?
Division 05 Metals. Structural steel framing is 05 12 00.
What's the difference between MasterFormat and UniFormat?
MasterFormat organizes by work results, for specs and bids. UniFormat organizes by building systems, for early estimates.
See what the AI reads on your own drawings.
Send one representative trade plan set. RenderDraw reviews it and follows up with what the AI extracted and what it flagged for review. Your files remain private while the request is assessed, and there is no obligation.
- Upload the plan set, legends and schedules, the spec sections for your scope and any addenda.
- RenderDraw reviews the set and the scope you want tested.
- We follow up with extracted quantities, flagged items and next steps.
Where these numbers come from
We checked this guide against the standards, manufacturer documents and industry references below (last reviewed November 2026). Figures marked as rules of thumb are typical ranges, not requirements; your project documents, local code and your own cost history govern.
- MasterFormat 2026 (CSI) — 2,185 new and 617 reorganized listings; division-level changes