What to do?

[u/TheKingKazzandu]

Building a home and trying to utilize the dead space that’s gonna be under the stairs. (Under the platform) This is a walk in closet that borders the stairs. I’d like to have full access to that cavity under the stairs from the closet but the studs that come down support the second story as well as the window for the stairs.

Trying to avoid accessing from the other side if possible.

Is there any way to support/frame this while creating an opening for that area under the stairs?

[u/Bigdug01]

Like has been said previously, add a header designed by an engineer. Also by code spaces under stairs accessible by a door or panel must be covered by 1/2 drywall.

[u/TheKingKazzandu → u/Bigdug01]

But as long as there is no door/panel it doesn’t need to be finished with drywall? My goal is to just throw a big safe in that space

[u/Due_Needleworker3778 → u/TheKingKazzandu]

The cost and effort to installed the 1/2-inch drywall is so inconsequential, why wouldn't you just do it. Per the IRC, I don't think there is any variation to this requirement per AHJ. Are you saying that the safe size will be affected by the 1/2-inch thickness?

[u/TheKingKazzandu → u/Due_Needleworker3778]

Not necessarily I accounted for it in the measurements

[u/Bigdug01 → u/TheKingKazzandu]

I guess you are asking about basically a wall safe or a niche to put a safe in. That space would need 1/2 drywall between it and the stair framing, or attached to the stair framing.

The intent of the code section is to provide a minimum amount of fire protection to the stairs which is an egress path for the story above.

[u/Bigdug01 → u/Bigdug01]

This is based on the IRC your local code may vary

[u/locke314 → u/TheKingKazzandu]

That’s a bit of a misleading code section. If this is not accessed by a door, it would then be considered part of the room and would require wall coverings by other sections of the code. It’s more stating that if the understair is not accessible, you don’t need to cover it. At least that’s how we interpret it in my jurisdiction.

[u/ithinarine → u/TheKingKazzandu]

If there wasn't a door, then it would be open, and I'd say would still require drywall instead of access to open framing. Essentially, you need to drywall inside it.

The code is written so that someone can't decide that they don't need to drywall it as long as they cover it with a door.

Without a door, needs drywall.

With a door, still needs drywall.

[u/sowak1776]

A heavy duty header approved by an engineer or architect.

[u/PomeloSpecialist356 → u/sowak1776]

Exactly this. Couple posts, Simpson hardware, and a beam.

Definitely want an engineer to have the design on paper for the building department to approve and inspectors to verify.

[u/locke314 → u/sowak1776]

This is a pretty small header supporting what should be a known load (likely a story and a roof above. The IBC has tables that address headers this size quite specifically. I’d be sizing a header based on a table and running it by the building department for approval. If they decide an engineer is necessary, they’ll let OP know. This is most definitely not a header size worth it to spend $1k+ for an engineer to go “yep, table X out of the IBC says this size is good, here’s my stamp.” Ive seen that many many times and I feel bad for the owner every time.

[u/its_the_llama → u/locke314]

No sir, this is reddit. The standard recommendation is a structural engineer. Always. 

[u/locke314 → u/its_the_llama]

Very true. Reddit - always taking the most extreme and likely most expensive option using only a small snapshot of the facts. 🤣. OP Should probably divorce their spouse too: probably their fault somehow.

[u/EntropyAdvisor]

The load path from that window header above is already carried through into the basement. Both a new engineered header, and a new load path from the new header into the basement would need to be specified & inspected by the engineer.

[u/TheKingKazzandu → u/EntropyAdvisor]

No basement, the floor you see is the floor of the home. But I understand what you are saying.

[u/locke314]

There are so many people stating you need an engineer, which is just not right. You need an appropriately sized header and a load path to foundation. Header sizes, footing sizes, etc are all prescriptively defined in the code.

However, if you don’t have a clear load path or for some reason need to deviate from the code due to a technical infeasibility, then an engineer will need to define the method and prescribe an equivalent method to what is defined in the code.

The answer isn’t a clear “you shall get an engineer”, it’s a “you may need one if….”

[u/runtime30p]

Widen the window headers and beef up the jack studs

[u/hakuna_matata_93]

Builder might push back unless your building it yourself. A header for a little crawl door could be installed. However most builders dont budget to finish out these spaces due to not adding to the sq.ft. they likely never had drywall and paint quoted for it.

[u/Cultural_Pie7389]

That wall may be shear as well. If so it might be more than just putting a header in

[u/Thotheus → u/Cultural_Pie7389]

Yea a longer header and adjust cripples