This topic comes up about every three or four years. It is normally resurrected by those who don’t specify facility services specifications. This is proven true by the lack of understanding of what is and is not “common.”
The reality about “common” versus “unique” and “redundant” as opposed as “not redundant” is that the commonality of the topics in the categories of 2X 05 00 is true about Section, Article, and Paragraph titles; and beyond those titles the content is not, and should not be the same. There will certainly be a minor bit of overlap among various topics, however, the static and dynamic loads, pressures, temperatures, and other design factors among the topics of Fire Suppression, Plumbing, HVAC, Electrical, Communications, and Electronic Safety and security are vastly different. This truth applies to hangers and supports, meters and gages, general duty valves, identification, conductors and cables, raceways and pathways, overcurrent protective devices, and more when considered among the seven divisions in Facilities Services Subgroup.
A division 20 would need to contain common work results for all services. To do so would require some subdivisions at Level 1-1/2 and Level 2 numbers and titles to differential, say, electrical common work results from HVAC common work results. In so doing, the results are the same as what appears in each of the seven Services Subgroup divisions. So, why move them from where they apply to a new division?
The interdependence among sections within each division in the Facilities Services Subgroup is dramatic; much more so than in the Facilities Construction Subgroup. However, the same principles could be applied to the latter as are applied in the former. For example, in plumbing systems, each piping system is specified in a separate section (e.g., Domestic Water, Sanitary Waste and Vent, Storm Drainage, Compressed Air). Each system has common components (e.g., pipes, fittings, specialties), each of which is chosen from an ever-expanding variety of product types that are applicable and unique to the application of each particular system. In each piping system section cross reference is made to hangers and supports in a 22 05 00 category section to avoid repeating them in the several piping system sections. Spacing of hangers and supports is, however, specified in the system section because that spacing depends on the piping material chosen for various locations, sizes, and conditions at various parts of the system. The Hangers and Supports section in Division 22 will have some overlap with Division 23 (not with 21 and certainly not with 26, 27, or 28), but the dynamic and static loads, temperatures, and pressures will require differences between the two. So, a hanger for domestic water piping will likely have different requirements for high-pressure steam piping, as an example.
Here’s an interesting observation, the architectural community has not embraced the same redundancy eliminating principles as the MEP community, either within divisions or among divisions as they are professing for Facility Services Subgroup. Divisions 3 through 14 have "XX 05 00 Common Work Results for (Insert the Division Title), but these are rarely if ever used. Also, among those divisions in the Facility Construction Subgroup, there are (or could be) items that are common among most (e.g., fasteners). However, I don’t see (for good reason) a movement to create a division to consolidating these common work results.
The MasterFormat Expansion Task Team and after that the MasterFormat Maintenance Task Team, for the first time in MasterFormat history, engaged facility service engineers and organizations to revise and expand the classification for facility services specifications. Having serviced on MF committees since the mid-1980s I can attest to that. When that happened, two and one half divisions (13-, 15, and 16) became seven divisions with a few more (24 and 29) for future expansion. Divisions 20, 30, and 40 were not considered to be a classification number to be used, although the Environmental Engineers chose to make use of Division 40 (for reasons inconsistent with the rest of the classification system). This expansion was done deliberately and carefully to accommodate the vastly larger quantity of product types and work results and to align the classification system for subject matter in facility services with the classification for subject matter in facility construction. Each work result section in facility services described large amounts of products and the application of them into the project. These complex issues demanded expansion of the number of divisions and sections to enable more comprehensive and concise coverage of these requirements and to be able to locate that subject matter within the project manual. To consolidate Common Work Results into a single division would to move backwards and require larger sections containing many more products and contradicting the underlying principle of easing retrieval of requirements. I believe in the Tenant of “Say it Once,” but until one actually designs, select products for, and specify work results for facility services, one cannot understand the complexities affecting the decisions for the classification.
Buildings are becoming much more complex, intelligent, and dynamic. So, facility services specifications will continue to expand and require careful and considered organization. My architectural friends and colleagues, get used to the fact that the quantity specifications and drawings for facility services will eclipse those for architectural.