The minimum width (and depth) is the width of your stairway - so 36". The requirement for doors opening over a landing not reducing width to less than half is for the situation shown in the image below (from 2012 IBC commentary). As your landing is only serving as egress through the door, it is not really applicable in this situation (at least that's my understanding).

Thanks for your response!
Per figure 1009.8(4)above, I think my landing width should be 54 inches [36"(stairway width)+ 18" ( 1/2 required width of stairway)].
Also, based on IBC-2015/Section 1011.2 the minimum width shall not less than 44 inches ==> it's qualified as well. Please advise

Technically, we have a straight-run stairway, so 44" min required for my landing dimensions (IBC-15/See Figure 1011.6(1))

1011.2 is for the width of stairways - which it does limit to 44" with the exception that if the stairway is serving an occupant load of less than 50 the limit is 36" (your drawing shows the stairway having a width of 36" and you stated the occupant load is 5, so 36" works).

So, as stated above, the minimum width of the landing is determined by the width of the stair per section 1011.6 which we have established as 36". The only other thing that impacts the width of the landing is the statement in 1011.6,"Doors opening onto a landing shall not reduce the landing to less than one-half the required width." I provided a figure that is in the commentary that shows the intent of this requirement is to allow egress past the open(ing) door for occupants that are coming down another flight of stairs that terminates at the same landing (think fire escape of a building). Your situation does not fit with this - the only occupants that your stair and landing serve will have to come through that door, so there is no need to ensure you have room to get around the door.
The depth of the landing must also be at least as deep as the width, so 36".

You can certainly provide a landing that is larger than 36" by 36", however it is not required to be by code.

Thank you so much for your replies!
And I'm still have a question regarding to IBC-2015/Figure 1005.2. Based on this figure, do I have to satisfy the highlight condition on the picture below when IBC commentary said that it's also applied to platform as well:

Here is the copy I got from IBC-15/ Section 1020.3 Obstruction:

The intent of the code is to make sure that doors (when opened) do not impede the egress of occupants that may be trying to move past said door. In the images above, the door is opening into a corridor that serves traffic moving past the door in question.

Your situation is different in that the landing only serves the door. If the door swung open so that it was on the same side of the landing as the stair you would need at least the minimum width - 7" (36-7 = 29") so that people are still able to exit the door and move past it down the stairs (egress path shown in green). See image below for this situation:


However, your door should/will open the opposite way so that it will not impede the egress path (shown in green). So, the only requirement is that the door does not stick out more than 7" when open (a typical door won't) as shown below:


The minimum opening requirement that is shown in the first image is not required in the second image as there is no egress path that needs to move past the door.

Thank you so much for your time! And have a good weekend

Do we need to comply with IBC-2015/Section 1010.1.6 Landings at doors? If not, can you tell me why

Yes, you would need to comply with that section - so you would need a minimum depth of 44".

So we can't use 36"?
Also, do we need to apply 44" + 44"/2 = 66" min per that section? Please advise

Any suggestions? Thanks

The one-half width requirement remaining clear with door in any position does not apply as your occupancy is less than 50.

Per section 1010.1.6 the landing width shall not be less than the width of the door or stairway. For your situation, both the door and stair are 36" wide, so the landing needs to be a minimum of 36" wide.

Per section 1010.1.6 the landing must have a length (in direction of travel) of at least 44" - this would be the direction you travel through the door (left to right in your picture).

Per section 1011.6 the landing must be at least as wide as the stairs (left-right direction on your picture), so 36".

Per section 1011.6 the landing must have a minimum depth (defined as parallel to direction of travel on the stairs, top to bottom on your picture) of at least the minimum of 48" or the stairway width, whichever is less - so 36", the stairway width would control

Putting all of the requirements noted above together results in a landing that needs to he a minimum of 44"x36" as shown in the image below:

Thanks for your clear details!

Per IBC-2015/section 1011.6, I haven't found the minimum depth per your stated above.
https://codes.iccsafe.org/content/IBC2015/chapter-...

Sorry, I was looking at 2018, when I pulled that requirement. 2015 does not have such a requirement.
https://codes.iccsafe.org/content/IBC2018P4/chapte...


With or without that requirement, the other requirements still result in the dimensions shown in my last post.

Are you looking on the IBC-2015 Code and Commentary? I attached below from 2015-IBC

My last post was showing what is in the 2018 code - I mistakenly looked at it and that is where the minimum depth requirement I cited came from.
I don't actually see a minimum depth requirement in the 2015 code (in this section), just a statement that it need not exceed 48"

Based on IBC-2015, I will go with 44" minimum depth & width landing to satisfy with both sections listed above for my case (A straight run stairway. Do you agree?

My last question is that my case is qualify for Section 1005.7 deals with door encroachment and egress width and capacity? Thanks anyway

Any clues? Thanks

I believe the requirements of 1005.7 fall into the same discussion we had above, particularly the post with this time stamp: 2 Oct 20 15:39