Exit Corridor Width – How to determine – Building Codes

Exit Corridor Width – How to determine – Building Codes

Exit Corridor Width – Building Codes

As an Architect, I interact with clients, engineers and contractors who have acquired bits of information about Building Codes.  Sometimes, those bits are misconceptions and regurgitated information.  The building codes can be intimidating and have no beginning or end. To learn the code, the best way is jumping in feet first.  

Upcoming Blog Posts

In the next series of blog posts, I will explore common simple and more complex Building Codes.    Each City has adopted a code but most in Arizona use the IBC (International Building Code).

The issues to be addressed in the following Blog Posts are:

  1. Door swing direction.  Which way should the door swing, out of a room or in?
  2. Number of exits within a room?
  3. Door Size.  Who said “size doesn’t matter.”
  4. Exit corridor width.  How narrow can a hallway be?
  5. Clearances around a door?  Door arrangement between two doors.  
  6. Door fire ratings.  Is your door fire rated?
  7. Exit Travel Distance.  
  8. When is an elevator required?
  9. Should my door have panic hardware? 
  10. Do I need an Drinking Fountain?
  11. Minimum size of a single person toilet room?
  12. Small commercial space, is one bathroom enough?

The item in bold to be addressed in this post.  As an Arizona Architect, most City’s jurisdictions work with the IBC (International Building Code).   The code analysis is based upon the IBC.

Exit Corridor Width

Exit corridors are the enclosed exit access component that provides a path of egress outside of the building.  The size of the corridor is to allow for safe passage of occupants within the building.  Exit corridor is determined by minimum size requirements and occupancy loads.  As you explore the code, you see a trend that occupancy load effects many elements of the building.

Exit corridor width - Serbin Studio Inc.

The code indicates: Minimum exit corridor width  44″ with some exceptions.  See occupancy calculations below.

  • 24″ for access to electrical, mechanical  or plumbing systems
  • 36″ for occupant loads less than 50
  • 36″ in residential
  • 72″ in Educational occupancy with greater than 100 occupants
  • 72″ in medical facilities with gurney’s
  • 96″ in  in Group I-2 for bed movement which essentially is hospital, nursing homes etc.

Height of ceilings within corridor must maintain 7′-6″ minimum.

Occupancy calculations

Besides the minimum requirements, the # of occupants also determine size of exit corridors.  In building over 1 story, stairwell may determine corridor width as well.

Total width of corridor = # of occupants (times) 0.2″/ per occupant

Total width of stairwell = # of occupants (times) 0.3″ / per occupant

Which ever number is greater takes precedent.   See example below.

Exit corridor width - Serbin Studio Inc.

In addition to minimum corridor width, additional code requirements may take precedence.  For example, ADA door clearances.   Also door swings can effect corridor widths as they can only minimally impede the corridor if swinging into it.  Those issues will be explained in a later blog post

Summary

The width of a corridor is dependent upon minimum requirements, calculations based upon the number of occupants within a building and door clearances.  As the buildings become larger and have larger # of occupants, such as building with assemblies, the corridor width can grow significantly.

So when desiging a new building, size the corridor accordingly.  When retrofitting an existing facility and have a change of occupancy type, verify if the existing corridors can handle the change in the # of occupants.   However when in doubt, rely on an Architect to explore the code and assist you.

Door Size – Does Size matter?  Size is dependent on building code.

Door Size – Does Size matter? Size is dependent on building code.

Door size – Building Codes – Size Matters

As an Architect, I interact with clients, engineers and contractors who have acquired bits of information about Building Codes.  Sometimes, those bits are misconceptions and regurgitated information.  The building codes can be intimidating and have no beginning or end. To learn the code, the best way is jumping in feet first.  Door size matters.

Upcoming Blog Posts

In the next series of blog posts, I will explore common simple and more complex Building Codes.    Each City has adopted a code but most in Arizona use the IBC (International Building Code).

The issues to be addressed in the following Blog Posts are:

  1. Door swing direction.  Which way should the door swing, out of a room or in?
  2. Number of exits within a room?
  3. Door Size.  Who said “size doesn’t matter.”
  4. Exit corridor width.  How wide or narrow can a hallway be?
  5. Clearances around a door?  Door arrangement between two doors.
  6. Door fire ratings.  Is your door fire rated?
  7. Exit Travel Distance.
  8. Do I need an Elevator?
  9. Should my door have panic hardware? 
  10. Do I need a drinking Fountain?
  11. Minimum size of a single person toilet room?
  12. Small commercial space, is one bathroom enough?

The item in bold to be addressed in this post.  As an Arizona Architect, most City’s jurisdictions work with the IBC (International Building Code).   The code analysis is based upon the IBC.

Door Size

Does size matter!   That’s huge.

Doors are a means of egress within a building.  The size of door is to allow for safe passage of occupants within the building and to allow for exit in case of emergency.  The size allows for egress of able body and occupants using wheelchairs.  Door Size is determined by minimum size requirements and occupancy loads.  As you explore the code, you see a trend that occupancy load effects many elements of the building.

The code indicates that a door provide a minimum of 32″ clear when open 90 Degrees.  If you look at the specific detail below, depending on door thickness, the door hinges used and the clearances you take into account around the door itself, a door itself has to be minimum ~2′-11″ wide.   For ease of construction, doors are typically 3′-0″ or 36″ wide to take into account variables in the components.  There are however a few exceptions to the code.  Those pertain mainly to residential projects, storage closets and revolving doors.  Projections into the clear width such as door handles, stops, closers, etc. are allowed at 34″ above finish floor as long as they don’t exceed 4″ into the clear space.

Door size minimum in commercial building

Door size minimum in commercial building

If size matters, who said it’s too big?   Per IBC (International Building code), maximum width of a swinging door leaf shall be 48″.

DOOR SIZE

Who said it’s too big!

Door height minimum is 80″ or 6′-8″.  I have yet to find in the code a maximum height of a door.   A governing factor may be how easy / difficult it is to open the door itself.  There are requirements in the code for the maximum force required to open a door.  So I suppose, a door too big would exceed those.  If you find a section, let me know.

Means of Egress

Another factor to door width relates to occupancy quantities.  Means of Egress  – “The continuous and unobstructed path of egress travel from occupied space to a public way”.   The minimum size of the door or doors can also be affected by this requirement.  For example, if an occupant load exceeds 160, the door width of 36″ will not suffice as shown in equation below.

Per IBC 1005.1, means of egress width is determined by the number of occupants x 0.2 inches.

160 occupants x 0.2 inches = 32 inches.

Therefore if the occupant load through a door is greater than 160 occupants, a single 36″ wide door would not suffice.  Possibly a 48″ wide door would work, but in most scenarious, (2) 36″ doors or multiple exits doorways would handle this scenario.  Note: stairwells have a multiplier of 0.3 inches.

Additional Requirements

Within Assembly occupancies, means of egress and exits have different requirements as shown in IBC  section 1028.  If your interested in further analysis, I will cover that in another blog post.

Summary

Door size does matter.  The code clearly indicates the minimum and maximum size of doors.  Occupancy quantities has some affect but as depicted, on larger scale projects.  On many projects, a typical 36″ door will suffice in an exit condition unless you exceed specific thresholds.

When learning building codes, once you begin digging into the code, it begins to make sense.  However when in doubt, rely on an Architect to explore the code and assist you.

Number of Exits Within a Room – Building Codes

Number of Exits Within a Room – Building Codes

Number of Exits Within a Room – Building Codes

As an Architect, I interact with clients, engineers and contractors who have acquired bits of information about Building Codes.  Sometimes, those bits are misconceptions and regurgitated information.  The building codes can be intimidating and have no beginning or end. To learn the code, the best way is jumping in feet first.  

Upcoming Blog Posts

In the next series of blog posts, I will explore common simple and more complex Building Codes.    Each City has adopted a code but most in Arizona use the IBC (International Building Code).

The issues addressed in the following Blog Posts are:

  1. Door swing direction.  Which way should the door swing, out of a room or in?
  2. Number of exits within a room?
  3. Size of the door.  Who said “size doesn’t matter.”
  4. Exit corridor width.  How wide or narrow can a hallway be?
  5. Clearances around a door?  Door arrangement between two doors. 
  6. Door fire ratings.  Is your door fire rated?
  7. Exit Travel Distance.  
  8. Do I need an Elevator?
  9. Should my door have panic hardware? 
  10. Do I need a drinking Fountain?
  11. Minimum size of a single person toilet room?
  12. Small commercial space, is one bathroom enough?

Item in bold is addressed in this post.  As an Arizona Architect, most City’s jurisdictions work with the IBC (International Building Code).   The code analysis is based upon the IBC.

Number of Exits within a Room

The number of exits within a room is determined by the occupancy and the level of hazardous condition.  The type of Occupancy (ie.  office, retail, industrial etc.) generally determine quantity of occupants based upon a load calculation. For example:

Architect in Arizona - occupant load table

Portion of Occupancy Table

Once the number of occupants is determined, a maximum number of occupants are allowed before second or possibly third exit is required.  The general rule of thumb are as follows:

Number of Exits Rule of thumb

In occupancy’s such as business group (offices), Assembly (Theaters, night clubs, restaurants), Educational (Schools), Factory (manufacturing), Mercantile (stores, markets, retail) and Utility (agriculture buildings, barns, sheds), if occupant load stays below 49 people, one exit is required.  Other factors may play into the requirement, such as travel distance, but  that will discussed in a later blog.

In hazardous occupancy’s, the maximum occupant load is greatly reduced to either 3 or 10, depending upon the use, before a second exit is required.  In storage occupancy the number of occupants allowed before a second exit is required is 29.

Once occupant loads reach greater numbers, such as 501 – 1,000 occupants, minimum 3 exits are required.  Beyond 1,000 occupants, four exits are required.  An example of this may be a large conference room or convention center where spaces are large enough to hold these quantities.

Another requirement to take into account is location of the exits themselves.  A good rule of thumb to follow is that the distance separating the exits must be greater than 1/2 the distance of the overall diagonal dimension of the room.  So in a large office space that is an open plan with no walls, such as the one depicted below,  the number of occupants possible by code would be 12,000 s.f. / 100 s.f. per person = 120 occupants.  this exceeds 49 occupants therefore 2 exits required.  See graphic below.

Building Codes - exit calculation

Exit calculation

Summary

Number of exits and their separation are dependent upon occupant loads.  Once a threshold of occupants are met, exit quantities increase.  Separations of those exits are required to allow for occupants to safely exit in time of emergency.  For example, if a fire occurs within one side of the room, having adequate separation ensures that both exits are not blocked.

When learning building codes, once you begin digging into the code, it begins to make sense.  However when in doubt, rely on an Architect to explore the code and assist you.

Door Swing

Door Swing

As an Architect, I interact with clients, engineers and contractors who have acquired bits of information about Building Codes.  Sometimes, those bits are misconceptions and regurgitated information.  The building codes can be intimidating and have no beginning or end. To learn the code, the best way is jumping in feet first.  

Upcoming Blog Posts

In the next series of blog posts, I will explore common simple and more complex Building Codes.    Each City has adopted a code but most in Arizona use the IBC (International Building Code).

The issues to be addressed in the following Blog Posts are:

  1. Door swing direction.  Which way should the door swing, out of a room or in?
  2. Number of exits within a room?
  3. Size of the door.  Who said “size doesn’t matter.”
  4. Exit corridor width.  How wide or narrow can a hallway be?
  5. Clearances around a door?  Door arrangement between two doors.  
  6. Door fire ratings.  Is your door fire rated?
  7. Exit Travel Distance.  
  8. Do I need an Elevator?
  9. Should my door have panic hardware? 
  10. Do I need a drinking Fountain?
  11. Minimum size of a single person toilet room?
  12. Small commercial space, is one bathroom enough?

The item in bold to be addressed in this post.  As an Arizona Architect, most City’s jurisdictions work with the IBC (International Building Code).   The code analysis is based upon the IBC.

Door Swing Direction

A buildings exit pathway typically consists of and exit pathway with hallways containing doors from offices, restrooms, mechanical rooms, leading to the exterior.  In certain scenarios, the doors can swing either in or out.   In some cases, functionality within the space dictates a swing direction unless code overrides.  Below is a graphic showing door swing IN versus OUT.

Arizona Architect - Code - Door Swing

There are sliding doors, roll up doors, revolving doors, however ‘most’ of those do not meet code requirements.  I say ‘most’ because there are some exceptions and some manufacturers who have come up with creative solutions around this issue.  Note in the graphic above, the door swinging out or into the hallway would block circulation.  There is code requirements for clear hallway width, which will be discussed in upcoming blog posts.  In this scenario, swinging into the office was preferable.  Each office was small enough to allow doors to swing in.

Hinged (swinging) doors required unless:

  • Private garages, office areas, factory and storage areas with an occupant load of 10 or less.
  • Group I-3 Occupancies used as a place of detention
  • Critical or intensive care patient rooms within suits of health care facilities
  • Doors serving single dwelling unit (apartments/child care) under specific occupancy count (see code)
  • Doors serving a bathroom in Occ. R-1 (residential)
  • etc.  The code goes into more details with exceptions

The factors which typically dictate the direction of the door swing are as follows:

  1. Number of occupants.
  2. Type of Occupancy
  3. Hazardous condition of room

Number of occupants is determined by Occupancy type.  For instance, the code has a table which calculates the number of occupants per s.f.  For example, an office space of 4,000 s.f. would have an occupant load of 4000/100 or 40 occupants.  See example below.

Arizona Architect - occupant load table

When occupant load is 50 or greater, doors shall swing in direction of travel or ‘out’.

Office Scenario

In the example below, each office may have less than 50 occupants.  Those individual office doors swing in.   The accumulation of all  office occupants however exceeds 50 occupants.  The door out of the general office area to the main exit corridor (in dark red) would need to swing ‘out’.

Arizona Architect - door swing analysis

Other factors such as hazardous conditions can dictate the swing of a door.  For example, within an electrical room, when the overall power exceeds 1200A, doors must swing in direction of travel.

Summary

What is the reasoning for swinging doors in the direction of travel in larger occupant loads or hazardous conditions?  Imagine you are at an event with over 50 people and an emergency occurs, such as a fire.  If you are the first person to reach the door and all 50 people rush in panic to the exit door at the same time, it would be difficult to swing the door towards yourself.   Everyone would be pushing to move forward and out of the space. Therefore, swinging out would be easier to open.  The code is created, reviewed and modified from years of learning from past mistakes.

When learning building codes, once you begin digging into the code, it begins to make sense.  In regards to door swing, swinging in the direction of travel or outward will work for all conditions in the code.  However when it is not required, such as in a small office, storage room or bedroom, functionally it may make sense to swing into the room.  Look at how many occupants are within the room and determine if the room is a hazardous condition.   When in doubt, rely on an Arizona Architect to explore the code and assist you.

Animal Hospital Design

Animal Hospital Design

Animal Hospital Design in Arizona

Building a new Animal Hospital Design in Arizona, a Grooming Facility or boarding facility is a humbling and exciting endeavor. The most important part of the process is to put together a qualified team to tackle the project.  The team may comprise of the following:

  1. Architect
  2. Accountant
  3. Banker
  4. Construction Manager

Where do you begin?  First start with the dream and visualize what the facility may comprise of.  If its a Hospital, how many exam rooms or surgical tables do you desire?  Will the facility include grooming?  Boarding animals overnight?  Boarding cats, dogs or other types of animals?  Will the building be for small or large animals?  Many of these questions should be asked, but as part of the dreaming, a budget needs to be blended into the dreams so the project is practical.

Planning

The project will not be simply putting a drawing together, getting an estimate, financing and constructing the building.  You will spend time working with the team to come up with the details, specifics for the layout of the building and the type of equipment you desire to function properly.  Are you looking at an existing building and doing a tenant improvement or will you be creating a new building?   The process can take months and possibly years to see completion, depending on the steps required to create your dream facility.

Animal Hospital Design in Arizona - programming bubble diagram

Programming Bubble Diagram

Hiring an architect with veterinary experience certainly makes the project easier.  An architect can provide you with examples and guidelines that address many concerns from size of rooms, workroom flow within the facility, options in materials and code requirements.  The architect can take a look at an existing building and create floor plan options to explore the best us of the space.  When building a new building, floor plan options can explore the site for the best building approach, best solar orientation, best use of the parking for unloading of the pets and understanding the zoning requirements.

Animal Hospital Design in Arizona

Solar orientation

When financing a project, going to the lender or bank with only a dream vision is typically not enough.  The architect can take your dream and take the ideas in words and create the conceptual plans that allow a contractor to determine an estimated construction cost.  The lender will typically need a conceptual drawing, estimated construction cost and your business plan.  This information will give a good impression to the lendor, that you have a good plan for your new endeavour.

Construction

Once the design has been completed, the contractor has been selected, the building permits and other approvals are obtained and the financing has been established, the exciting part is watching the facility become a reality.  All the time and effort finally begins to pay off.  Your involvement is not finished as we strongly recommend your involvement during the construction.  During the construction phase, there are many decisions that need to be made.  The architect role should be overseeing the contractors construction to ensure they are using the correct finishes and equipment as specified in the drawings.  Your involvement should include the finishing touches, such as final approval of finishes, selection of furnishings and final walk through to ensure the project completion.

Animal Hospital Design in Arizona - construction Photo

Construction Photo

Summary

When working on a Animal Hospital Design in Arizona, investing in an architect with veterinary building experience will ensure the facility has been built with a design that satisfies your needs, has a good workroom flow, is built of quality materials and falls within a reasonable project budget.   Whether it is a tenant improvement or a new building, the process of creating a new Veterinary Facility (Animal Hospital), Grooming Facility or boarding facility can be a rewarding experience.

Animal Hospital Design in Arizona

Animal Hospital Design