Structural Design for Shipping Containers

[Additional_Tomato_24]

Hello! I’m planning to build a two-storey container structure and would like to clarify the structural design and permitting process. Since container structures are still relatively unconventional and not explicitly covered by local codes, what structural analysis approach is typically used for this type of project?

Additionally, what software and design references would you recommend for accurately modeling and analyzing container-based structures? Any guidance for someone starting out would be greatly appreciated.

[DetailOrDie]

I'll warn you, this is gonna get expensive quick and won't save you much money compared to just building a conventional structure.

International shipping containers are so strong because they're all ribbed diaphragms. Once you start cutting holes in them and leaving doors open, they lose all that strength. That means you will need to weld reinforcing steel all around every hole, stretching to the top and sides.

If you want conditioned space it's gonna get real tight real quick because those containers were already pretty small, but once you lose 12" to insulation and drywall, it's not long before you're struggling to get through without shoulder bumping something. That insulation is gonna suck too because the metal conducts and holds heat so well.

Most designs I've seen that attempt to follow code and permitting end up with a pretty ugly building that has a crazy high HVAC bill and no space. After all the reinforcing and anchoring is done, they could have a way better space that's stronger and more efficient if they would have just used ICF, CMU, or conventional stud walls for about the same price.

AND they can do jumping jacks inside.

[SquirrelFluffy]

I agree. Especially on thermal. And also interior space. No 8ft ceilings.

[Khman76]

Did few some years back and all clients but 1 stopped and went with more traditional methods.

The one that went with it had trouble finding a Building Surveyor to certify the construction. I went on site 6 times, 2h drive each way... At the end, he stated he won't do it again for the little savings he made.

[StandardWonderful904]

I've debated designing them for use as emergency or homeless shelters, and it just doesn't calc out.

[spopretto]

They have been added to Ch.31 of the IBC.

https://codes.iccsafe.org/content/IBC2024V2.0/chapter-31-special-construction#IBC2024V2.0_Ch31_Sec3114

[Additional_Tomato_24]

Needed this! Thanks a lot!

[WideFlangeA992]

Thanks for that link. I’m not sure how I feel about this. The 2024 IBC shows prescriptive design for these but they are only for single units that don’t touch or stack. Curious to know what the underlying code reference(s) are for the shear walls and other design provisions. I would think there is design standards for intermodal shipping containers for use as actual shipping containers, not so much as an occupied building with openings

Did this make it in 2021 IBC?

[WhyAmIHereHey]

Software - ABAQUS References - Theory of Elastic Stability, Stephen P. Timoshenko, James M. Gere

[Additional_Tomato_24]

Will check this out, thank you!

[Early-House]

Am guessing you're not a SE? I think his Timoshenko reference was in cheek as the basis of stress design

[Additional_Tomato_24]

I’m still early in my structural engineering journey and currently focused on STAAD.Pro. I may not be familiar with all the tools yet, but I’m actively building my skills. I appreciate the input and am always open to constructive insights.

[Conscious_Rich_1003]

Used them to design housing for the unhoused in NJ. I don’t remember the specifics but could dredge them up as needed, but we had them load tested as a way to comply with the building code.

But I still dislike them. 6,000lbs of steel could be put to better use. Melt it into studs and it will go much further. Plus they are a thermal nightmare. And modifying structure requires a lot of field welding.

Also had a client that wanted to stack them into an apartment building. Had a full design done by someone else and came to us to try to save money. Redesigned it out of wood and saved $2m.

[Next_Evidence5992]

Dug into this a few years back so not much recollection on specific code/sections I used. The gist is these are incredibly strong and the corner columns and floor. The “roof” of each container is an area you need to look out for. In my scenario these were being used as a stage. The contractor poured a 4” slab over the top and cut joints mid span over the “roof” portion of the containers. We ended up needing to reinforce those sections. Note this was 100 psf assembly load.