CSI MasterFormat Divisions Explained for Estimators and Contractors

Every set of commercial specifications in the United States is organized the same way, and most estimating software, bid forms and schedules of values follow it. CSI MasterFormat is the numbering system that makes that possible. Estimators who know it fluently find scope faster, miss less and produce estimates that owners and general contractors can read without a translation call. Here is what the system is, what the divisions contain, and where scope gets misfiled.

What MasterFormat is, and what it is not

MasterFormat is a master list of titles and numbers for organizing construction information by work result, meaning by the thing that gets built or installed, not by who installs it. It is published jointly by the Construction Specifications Institute and Construction Specifications Canada and is revised periodically; the 2004 edition expanded the list from 16 divisions to 50, and the 2018 edition is the version most current specifications follow. Each section number has three pairs of digits: division, then two levels of detail. 03 30 00 is cast-in-place concrete; 03 35 00 is concrete finishing; 03 35 13 is high-tolerance concrete floor finishing.

What MasterFormat is not is a trade or subcontract breakdown. An electrical subcontractor's scope may touch Divisions 26, 27, 28, 03 and 31. A specification section does not tell you who buys or installs the work; the Division 01 requirements, the drawings and the bid form do.

The 2018 division structure

The 50-division framework is organized into groups. Many numbers are reserved and unused, which is why the list jumps from 14 to 21, from 28 to 31, and from 35 to 40. The table summarizes the groups; the list that follows covers the divisions that appear on nearly every building project.

• 02 Existing Conditions: selective demolition, hazardous material abatement, site remediation.
• 03 Concrete: formwork, reinforcing, cast-in-place, precast, grout, finishing and curing.
• 04 Masonry: CMU, brick, stone, mortar, masonry reinforcing and accessories.
• 05 Metals: structural steel, joists, deck, cold-formed framing, stairs, railings and miscellaneous metals.
• 06 Wood, Plastics and Composites: rough carpentry, blocking, sheathing, finish carpentry, architectural woodwork, composite decking.
• 07 Thermal and Moisture Protection: waterproofing, insulation, roofing, siding, firestopping, joint sealants, expansion joint covers.
• 08 Openings: doors, frames, hardware, windows, curtain wall, storefront, skylights, louvers, access doors.
• 09 Finishes: gypsum board, tile, ceilings, flooring, wall coverings, painting and coatings.
• 10 Specialties: toilet accessories, partitions, signage, lockers, fire extinguishers, flagpoles.
• 11 Equipment and 12 Furnishings: foodservice, laboratory and athletic equipment; casework, window treatments, seating.
• 13 Special Construction and 14 Conveying: pre-engineered structures, pools, controlled environments; elevators, escalators, lifts.
• 21 Fire Suppression, 22 Plumbing, 23 HVAC: sprinklers and standpipes; domestic water, sanitary, gas, fixtures; ductwork, hydronic piping, equipment, controls.
• 25 Integrated Automation, 26 Electrical, 27 Communications, 28 Electronic Safety and Security: building automation; power, lighting, gear; structured cabling, AV; fire alarm, access control, video.
• 31 Earthwork, 32 Exterior Improvements, 33 Utilities: excavation, grading, shoring, piles; paving, site concrete, fencing, landscaping, irrigation; water, sewer, storm and site electrical utilities.

How an estimate maps to MasterFormat

A detailed estimate organized by division does two things. It lets a plan reviewer or general contractor compare your number to the specification sections line by line, and it makes scope gaps visible: a Division 07 estimate with no 07 84 00 firestopping line is an obvious hole. In practice we organize the takeoff by section number, carry the section reference on each line, and roll up to the division for the summary. Subcontractor bids are leveled against the same section list, which is the fastest way to see that one bidder carried joint sealants and another did not.

Schedules of values and pay applications

Most owners and lenders expect the schedule of values to follow the same divisions as the specifications, and many require it. Building the SOV from the division roll-up of the estimate, rather than from scratch after award, keeps the two documents reconcilable. It also protects you in change order negotiations, because the original value of a section is documented and added work can be priced against it.

UniFormat versus MasterFormat

UniFormat organizes cost by building system or element, such as A Substructure, B Shell, C Interiors and D Services, rather than by work result. It is the better structure for conceptual and schematic estimates, where you know the building has 48,000 SF of exterior wall but not yet which sections will specify it. MasterFormat is the better structure once there are specifications to price against. Many preconstruction teams estimate in UniFormat through design development and convert to MasterFormat at construction documents, when the bid packages and SOV need it.

Items that get filed in the wrong division

The misfiles below are the ones we correct most often when leveling subcontractor bids. Each one creates a gap or a double count, depending on who assumed what.

• Firestopping belongs to 07 84 00. It is frequently left to the drywall or electrical sub, and each assumes the other carried it. Name it in every scope letter.
• Blocking and rough carpentry belong to 06 10 00, including blocking for toilet accessories, casework, handrails and wall-mounted equipment. It is not drywall scope and not the specialties sub's problem.
• Roof hatches and smoke vents are 07 72 00 roof accessories, not Division 08 openings, even though they look like doors.
• Louvers are 08 90 00, often furnished by the HVAC sub and installed by others; check the specification for the hand-off.
• Housekeeping pads for mechanical and electrical equipment are 03 30 00 concrete, but the drawings show them only on the MEP sheets.
• Underslab vapor retarder is 07 26 00, missed when the concrete sub assumes it is Division 07 scope and the Division 07 bidder never looks under the slab.
• Joint sealants are 07 92 00 and cover far more than exterior joints: control joints in paving, perimeter joints at frames, tile joints and acoustical sealant at partitions.
• Insulation is split by what it insulates. Building insulation is 07 21 00; duct and pipe insulation are 23 07 00 and 22 07 00.
• Site concrete such as sidewalks, curbs and pads is 32 13 13 and 32 16 00, not 03 30 00, so the building concrete sub may rightly exclude it.

Practical habits that pay off

1. Read the table of contents of the project manual before the drawings. It is the fastest complete list of what is specified.
2. Carry the section number on every line of the takeoff and the estimate.
3. Level subcontractor bids against the section list, not against each other.
4. Build the schedule of values from the division roll-up before award, not after.
5. Keep a running list of the misfiled items for your trade and put them in every subcontractor scope letter.