History of CSI MasterFormat

What is CSI Masterformat?

What is CSI MasterFormat?


For anyone new to commercial construction, it seems like we speak a different language. Unlike residential projects, we’re always referring to specifications using a division, section, or title to communicate during the design and construction phase of a project.  The lingo is consistent from state to state and from site to site.  But this wasn’t always the case.  


In the first half of the 20th century, communication amongst design and construction teams was inconsistent from project to project. A California project might specify concrete in Section 8A, while in Texas, Section 32 defines the same scope. Locating information was troublesome, confusing for trades, and time-consuming for the entire industry.


So to improve the process, a group of engineers from various US government agencies created an informal think tank in 1947.  The objective was to discuss how to standardize the presentation of information, improve communication among all parties, create a more uniform specification system, consistency, and specifying work results and construction requirements.


Construction Specifications Institute (CSI)


After World World II, the engineer’s think tank grew into what we know today as the Construction Specifications Institute (CSI) in 1948.  An industry-wide organization with a primary goal of advancing specifications into a numbering system, and developing a systematic approach to organizing construction documents and standardizing forms.


In 1963, CSI Format for Construction Specifications was released, a numbering system with titles for organizing construction information into major Divisions of work.  The original release contained 16 Divisions with each Division subdivided into a number of Sections, organized by a five-digit numbering sequence and corresponding title.  A standard way of organizing information from project to project.  Example: Division 9 – 09650 Resilient Flooring 


In 1978, the name MasterFormat was used in a CSI publication and thus the new name was born.


Most of us in construction remember using the 16 Division publication, MasterFormat 1995 edition.  This was before the internet and it was distributed in paperback before the internet evolved.  If you research the old format, it looked something like this:

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Today, many of us refer to MasterFormat as the “Dewey Decimal System” of organizing products and assemblies using specifications. It promotes standardization, facilitates retrieval of information, and improved communication among all parties involved in commercial construction projects.


So the next time you hear the construction team refer to a Division, Section, and title lingo on a commercial project, remember CSI was born out of a think tank of engineers that set in motion the standard communication we use today.


CSI MasterFormat Divisions (Current) 


CSI MasterFormat continues to evolve and in 2004, CSI MasterFormat was expanded from 16 Divisions to 50 Divisions with each Section growing from five-digit into a six-digit numbering sequence and corresponding title.  CSI no longer supports the old MasterFormat 1995 – 16 Division and five-digit numbering, however, we continue to see comparison publications nearly 20 years later.

MasterFormat 1995 Example: Division 09 – 09650 Resilient Flooring 

MasterFormat 2004 – Division 09 – 09 65 00 Resilient Flooring


The expansion allowed CSI MasterFormat to adequately cover construction industry subject matter while providing additional space for more subjects at each level of classification, plus adding infrastructure and process equipment.  The older MasterFormat 1995 edition, using 16 Divisions simply ran out of space to properly address topics, and the lack of space often resulted in the inconsistent classification of information. 


The new six digits Sections, arrange the digits into three sets of paired numbers, one pair per level.  Paring the numbers allowed for more subdivisions at each level.  The expanded six-digit Section numbers and titles sequencing facilitates better retrieval of information and improved communication among all design and construction parties involved in commercial and industrial construction projects.


07 50 00 – Membrane Roofing 

07 51 00 Built-Up Bituminous Roofing (Level 2)

07 51 13 Built-Up Asphalt Roofing (Level 3)

07 51 13.13 Cold-Applied Built-Up Asphalt Roofing (Level 4)


As products continue to evolve and new innovations are released, CSI MasterFormat continues to be refreshed every two years.  It has now grown to 7,300 sections, however, the 50 Division structure remains the same.  


At first review, you’ll notice that CSI MasterFormat offers 7,300+ Section numbers and titles.  It’s primarily used to organize project manuals and detailed cost information, and relate drawing notations to specifications.  It’s common to only see a project include 100 to 350 Sections.   Meaning that not every product type will be specified using a MasterFormat or used on a project. 


The latest 2018 edition of MasterFormat includes changes and enhancements made for the 2018 Edition and replaces all previous updates and editions. It is produced jointly by the Construction Specifications Institute (CSI) and Construction
Specifications Canada (CSC).


Here is a CSI MasterFormat 2018 pdf free download or visit this link.


MasterFormat 2018



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The 50 Divisions are as follows:



Division 00 — Procurement and Contracting Requirements



General Requirements Subgroup

Division 01 — General Requirements

Facility Construction Subgroup

Division 02 — Existing Conditions

Division 03 — Concrete

Division 04 — Masonry

Division 05 — Metals

Division 06 — Wood, Plastics, and Composites

Division 07 — Thermal and Moisture Protection

Division 08 — Openings

Division 09 — Finishes

Division 10 — Specialties

Division 11 — Equipment

Division 12 — Furnishings

Division 13 — Special Construction

Division 14 — Conveying Equipment

Facility Services Subgroup:

Division 21 — Fire Suppression

Division 22 — Plumbing

Division 23 — Heating, Ventilating, and Air Conditioning (HVAC)

Division 25 — Integrated Automation

Division 26 — Electrical

Division 27 — Communications

Division 28 — Electronic Safety and Security

Site and Infrastructure Subgroup:

Division 31 — Earthwork

Division 32 — Exterior Improvements

Division 33 — Utilities

Division 34 — Transportation

Division 35 — Waterway and Marine Construction

Process Equipment Subgroup:

Division 40 — Process Interconnections

Division 41 — Material Processing and Handling Equipment

Division 42 — Process Heating, Cooling, and Drying Equipment

Division 43 — Process Gas and Liquid Handling, Purification and Storage Equipment

Division 44 — Pollution and Waste Control Equipment

Division 45 — Industry-Specific Manufacturing Equipment

Division 46 — Water and Wastewater Equipment

Division 48 — Electrical Power Generation


Specific specifications are used by each discipline to create a project, select one of the below SimpleSpecs™ repositories for examples:

Architectural specifications 

Historic Preservation 

Site Civil specifications

Structural specifications 

Interiors specifications 

Landscape specifications

Comprehensive specifications 



Are you a building product manufacturer? Working as a product manager, architectural representative, or a member of the marketing team, and you get a request for a CSI specification from a design professional, What do you do?