The Naughton Company

Tenant's Rules of Thumb
Builder's Rules of Thumb

Tenant's Rules of Thumb

General space allocation should be approximately 150 to 200 usable square feet per person. This figure can vary depending upon special needs such as audiovisual and projection facilities or unusual filing and storage requirements. For an accurate determination of space required, an office space planner should be consulted.

  1. Typical President's Office or Chairman of the Board
    250 to 400 sf (3 to 4 windows in length)

  2. Typical Vice President's Office
    150 to 250 sf (2 to 3 windows in length)

  3. Typical Executive Office (Executive Secretary, Manager or Administrative Assistant)
    100 to 150 sf (1 to 2 windows in length)

  4. Partitioned Open Space
    50 to 100 sf (Clerical Manager or Supervisor)

  5. Open Space
    50 to 100 sf (Secretary or Clerk space)

  6. Conference Rooms
    Allow minimum of 15 sf per person for the alter style or classroom seating. Allow 30 to 35 sf per person for conventional conference seating.

  7. Workroom
    Approximately 8' to 9' in width. This includes 30" counters against each wall with a 4' aisle between. The length depends upon the number of people working in the room and the amount of mail activity.

  8. Reception Room
    Including receptionist & seating for 2~ people, 150 to 250 sf including receptionist and seating for 6-8 people, 250 to 250 sf.

  9. File Room
    Allow approximately 7 sf per file. Suggested aisle width varies from 3' to 4'. Minimum is 2' to 8'.

  10. Library
    Allow 12" for hook shelves against walls, 24" for hack to hack shelving. Aisle space minimum is 2' to 8'. With seating for 4-6 people, 175 to 450 sf.

  11. Employee Lunch Rooms
    Allow 20-30 sf per person, not including kitchen. Kitchen and serving area should be aminimum of 1/3 to 1/2 of the dining room.

  12. Clerical Pool Areas
    Allow 80 to 100 sf of usable area per person.

  13. Corridors and Circulation
    20% - 50% of the total usable areas for executive offices; reception rooms; open clerical areas; conference rooms; libraries; file, mail and storage rooms; computer rooms. Suggested corridor widths are: 5' for principal office forridors; 6' for public corridors, 3'-8" to 4'-6" for secondary interior corridors. Clearance between desks should be at least 3'. Suggested width of corridors in which secretaries are located, 10'. This allows for standard 5' long secretarial desk and 5' passage way, which is comfortable passage for two people. Minimum for this type of corridor is 8'.

  14. Coat Closets
    Allow 1 linear foot for 4 coats - 3" per person.

  15. Water Coolers/Drinking Fountains
    Allow a minimum of 1 unit per 75 people.

  16. Standard Door Sizes
    Standard office door is 3' x 7'. Double entrance doors are either 5'-0" wide, or 6' wide (two 3' doors).

Builder's Rules of Thumb
  1. Suggested Column Spacing
    Column Spacing from 20' to 30' per bay is most desirable for interior planning purposes.

  2. Basic Plan Configuration
    A rectangular floor plan is generally preferred because it is more suitable for multi-tenant subdivision.

  3. Core Services
    Building core facilities include: Passenger and freight elevators, stairs, public washrooms telephone and electrical closets, and mechanical room for the floor only.

  4. Building Dimension
    Suggested width of building core is 20' to 40'. Suggested length of building core is 40' to 90'. Suggested dimension from glass line to building core at shallow side of rectangle is from 38' to 40'. Suggested dimension from glass line to building core at deep side of rectangle is from 50' to 65'.

  5. Window Mullion Spacing
    Suggested window mullion spacing is 4'6" to 5'. Window sizes determine perimeter office dimensions.

  6. Elevator Lobby and Public Corridors
    Suggested width of elevator lobby is 10'. Suggested width of public corridors is 3'8" minimum; 5' recommended; 6' optimum.

  7. Method of Calculating Gross Rentable Area
    There are a number of ways of measuring the amount of office space when calculating rent for leasing purposes.* Generally, it's the actual usable area (the tenant space within the demising exterior and core walls) plus a proportionate share of common building service areas, which normally include: lobbies, public corridors, restrooms, telephone and electrical closets, and air conditioning facilities. The building's shared areas average an additional 10% to 15% of the tenant's usable area. Among the most common methods is that of BOMA (Building Owners and Managers Association).

  8. ADA
    Refer to the America Disabilities Act guidelines for requirements relating to handicapped accessibility.