Facility Operations

Room Numbering Requirements

General Provisions

To facilitate way-finding and to uniquely identify each space within University facilities it is necessary to determine appropriate floor numbers and room numbers based on the Floor Numbering Standard and this Room Numbering Standard.  Room numbers in use in existing buildings will continue to be utilized unless there is the opportunity to renumber.  Renumbering of any space should be done in conjunction with the Facilities Planning and Development Department to ensure that duplicate room numbers are not assigned and that consistent application of this standard occurs.

This standard should also be utilized to assign numbers during the design development phase for renovation and new construction projects.  Working drawings for renovation or new construction should conform to this standard.  Furthermore, it should be provided, and discussed if necessary, at all project kick-off meetings when other University standards are also provided to A/E.

Questions regarding this standard should be addressed to the Facilities Planning and Development Department.  Please contact them to schedule reviews of any new room numbering requirements.



  1. Each space within a facility needs an associated number.  This includes both assigned spaces such as offices, laboratories, classrooms, residential rooms, etc. and unassigned spaces such as corridors, stairs, mechanical rooms, electrical closets, bathrooms and janitor closets, etc.

Unassigned Spaces


Room #

Corridors / Hallways




Mechanical Shafts






Dead Space


X = Floor


Y = Number


Figure - 1


  1. All room numbers within a building (with a single facility ID) must be unique.


  1. Room numbers in the Space Inventory and on digital plans (i.e. CAD, BIM) should match those found in the buildings whenever possible.


  1. Room numbers should only consist of numbers with alpha suffixes, i.e., 101A.  There should be no hyphens, commas, spaces, etc.  Furthermore, room numbers should not be 0 or a single alpha character.  Alpha characters L, O, and Q are not to be used due to confusion with the numbers one and zero.


  1. In cases where two spaces are combined into one, the lower room number should be used to identify the new space.


  1. Spaces opening onto corridors should receive base numbers such as 101, 102, 201, 202, etc.  Base numbers proceed clockwise around the building with the lowest number near the principle entry to the floor.  In a building base numbers should start at the same place on each floor whenever possible.


  1. Interior spaces opening off base spaces receive the base numbers with suffix letters such as 101A, 101B, etc.  Interior spaces are numbered clockwise about the base space with suffix ‘A’ being the closest to the principle entry.  


  1. Major interior spaces opening off interior spaces are treated as if opening directly off the base space.  Therefore, a room opening off 101A would be 101B rather than 101AA.  Minor spaces like small closets may be numbered in sequence or placed at the end of the series i.e., if 101A-101E are used for major rooms, a closet could be numbered 101F.  The exception to this is minor spaces (like small closets) in large buildings like the residential colleges.  In those cases a double suffix designation such as 101AA should be used.


  1. Room numbers are part of a numbering sequence based on the floor.  Basement rooms with physical numbers displayed are numbered from 001- 089, spaces that typically are not physically numbered, such as hallways and stairwells, follow the standards outlined in Figure -1 above; first floor rooms with physical numbers are numbered 100 – 189, spaces without physical numbers follow the standards outlined in Figure -1 above; etc.  Sub-basement room numbers and mezzanine room numbers follow the same pattern and are covered further below under Room Number Prefix Options No. 2.


  1. All doors opening off corridors or public spaces should receive a permanent identifying number including toilets, closets, mechanical rooms, etc.


  1. Unenclosed spaces such as alcoves, oversized lobbies, etc. should receive separate numbers for the areas that are assigned such as reception desks, work stations, etc.  The Facilities Planning and Development Department should define the boundaries of these spaces.


  1. Spaces where numbers are not normally displayed such as lobbies, corridors, stairs, etc. must still have associated numbers.  These numbers will typically only be seen on digital plans (i.e. CAD, BIM) and in the Archibus Space Inventory System.  Numbering for these spaces should be done sequentially using the 90-99, 190-199, 290-299 series. 


  1. Where possible, rooms along a corridor should be numbered odd on one side and even on the other, with numerically close numbers physically close.  To accomplish this, it is often necessary to skip certain numbers entirely.  Normally, odd numbers would be on the left and even on the right. 


  1. Adequate provisions should be made for future rearrangement of interior spaces, particularly in laboratory and classroom buildings.  This can be accomplished by numbering each bay with the main room number and using letter suffixes after the main number for the interior rooms.


Room Number Prefix Options


  1. In cases where a facility is divided into wings or entryways, a one-letter prefix should be added to the room number.  For example, Creative Arts Center is divided into wings, so numbers in the ‘T’ (Theatre) Wing would be T101, T190, etc.


  1. In cases where a facility has a concourse, ground floor, lower level, sub-basement, mezzanines, or a penthouse a prefix should be used there as well to identify the rooms on those levels.  Basement rooms do not need the ‘B’ prefix, but may have them to match existing signage.   Concourse floor rooms should be identified with the “C” prefix, Ground Floor rooms the “G” prefix, Lower Levels rooms the “L” prefix, Sub Basement rooms the ‘S’ prefix, Mezzanine rooms the ‘M’ prefix (i.e. M101 for 1st Floor Mezzanine, M201 for 2nd Floor Mezzanine, etc.), and Penthouse areas the ‘P’ prefix (i.e. P1, P2, etc.).  In cases where concourse floors, ground floors, lower levels, sub basements, mezzanines or penthouses are located in specific wings of buildings, a double prefix would be used with the wing prefix preceding the floor prefix, i.e., TS1, TM101, TP1, etc.


Physically Numbered Spaces

  1. All major interior doors, including all lockable spaces, should receive permanent identifying numbers.
  2. Room number signage should be applied to the adjacent wall such that the number is not concealed when the door is open.
  3. All room number signage should comply with ADA Standards for size, height from floor, Braille lettering, etc.