I would make it as deep as you can go and use 12" deep shelves. We have 12" deep shelves and there's room for just about anything without fear of things falling off a shelf (like they might do with 9" shelves). Don't do bifold. Your thinking is correct; use a regular door.

eta: our shelves are actually 11"D but they are 12" from wall due to hanging method.

check the size of most things you want to store in it. I re-measured my shelves and they are 16" deep (not 15"). I can fit 4 cans in a row (front to back with room to spare) that are about 15 oz size. 5 of Campbell soup cans. I try to keep just 1 type of item in a row.

I did put a more shallow shelf between 2 deeper ones. It would have caused some wall destruction to re- align the deeper shelves. The more shallow shelf works great for me - I put things on that shelf like the really small cans of olives, chilis, water chestnuts, 3 oz v-8 juice, etc. I think that shelf is about 6-7" deep.

Do allow a few inches over an item - but not a ton of space.

I put taller things at one end in the front space where the more shallow shelf isn't. I don't have many very tall things - I live alone and just cook for me, so I don't buy much in a large size. My spaghetti container is tall, my bottle of oil, a spare bottle of ketchup... I put extra boxes/containers of pasta behind those usually.

Make it as deep as you can even if the shelves aren't. You could put some more shallow shelves along one side. Hang some utensils on the other (like extra long things (spatula/tongs for grilling). I have a container on 1 side to hold grocery bags and one of those bags hanging on a hook on the other side (for empty containers to return to my sister). It can still be useable space!

Search Pinterest as they have some good diagrams on how to think about they layout etc

As the others mentioned, I'd go with the max depth you can have. For a 36" wide pantry, I'd go with a standard 24" wide door. That would allow usable shallow shelves along either or both of the pantry side walls.

Also consider whether to hinge to door swing left or right depending on a landing spot or your pathway to your prep area... no sense having an extra step or two to get around an open door each time you go to the pantry.

HTH, tmy

thanks for all the suggestions!

Our plans changed...the closet specs are now 5 feet across, 2 feet and 1 in deep. But this space is supposed to accommodate both a pantry and broom closet. I will probably borrow another 6 inches from the bathroom next to the closet (to make the closet 2 feet, 7 inches deep) . Any suggestions how I should divide the two spaces (what dimensions for each)? Want broom closet deep enough to have an ironing board hung on the door and be able to store a vacuum in the closet. (Thought I could access the broom closet from the rear foyer area, while the door/access to the pantry would be from the dinette area - thus creating single, regular doors for each closet (to use the back of the doors for storage).

Looks like the pantry will be 3 feet wide, 31 inches deep --> suggestions on most efficient use of the pantry given these dimensions? (9-12' shelves plus use side walls??) What/how do people use side walls efficiently ?

I received a ton of help with my tiny pantry remodel! Take a look at this thread and it might help :)

My Thread

A friend has a pantry that is similarly sized, and she has deeper shelves on the back wall (9-12") and very narrow shelves (4-6") on the side walls. It's very efficient. If you use a 24" door, you can do shelves between 5-6" on both sides without them getting in the way of the door.

Thank you - very helpful

Fixed shelves should not be deeper than 16", 14"
is better. If you have a standard 24" space, put 15" deep
shelves inside the pantry and 7" shelves on the doors to maximize storage.
See some examples and the basic rules of pantry design
at Pantry
Perfect: The “Can't Go Wrong” Pantry Design Rules

I have these nice sliding shelves in my pantry, but the bottom one just broke. I loaded it with too many cans. Too heavy. consider that. The screw hole is destroyed, so now I have to lift the bottom shelf to get it to go into place.