Aside from containers in bought houses or guilds/organizations, are there other 'safe' containers which will store items permanently (won't reset)?

Solution 1:

When you join a "college" or a "group" like Winterhold Academy or company in Windhelm, they give you a "dorm" room.

When you notice that some room might be yours open the console (tilde key) click on wardrobe to select it and type IsOwner and you should see who it belongs to exactly. If it is you, then it is a safe place to store your items.

Also to make sure you can put item in container and go away for 48h that is the time items know to disappear.

Note:aiming at bed and seeing if it is red or not is easy and quick way,but it is not the most accurate since you can sleep in some beds even if you don't own the cabinets...

Solution 2:

I tried to make a chest in Helga's Bunkhouse mine, since I decided to move in there. I made it mine using this method:

1. Make sure the chest isn't yours already.

2. Select the container by pressing ~ and type setownership.

3. Re-check if the chest is yours by selecting it and type isowner. If it says it's yours, your items can be stored safely.

Solution 3:

A good storage location, especially if just starting the game, are containers in Anise's Cabin - no need to purchase a house, or join an organization.

This cabin may be one of the first inhabited locations you encounter upon escaping from Helgen.

The cabin's basement is non-respawning, meaning that all containers are safe for storage. Several of the containers on the ground floor of the cabin are also standard safe containers (e.g., the cupboard and dresser). Be careful, as the barrels are not safe.

This makes Anise's cabin a good starter home, since it has an alchemy lab, an arcane enchanter, a bed, safe storage, and is a fast travel destination. However, you cannot ask a Spouse to move here.

Also, the UESP Wiki lists safe locations for storage in Skyrim.

Safe locations are places that never respawn. Therefore, every container in the location (even a common barrel or sack) is safe for storage. Unless noted otherwise on the place page, only the interior areas of these locations are safe — i.e., only regions that are entered through a door that triggers a loading screen, and have their own map, separate from the exterior map.

In a few instances, there may be quest-related changes to the location (as noted on the individual place page), but otherwise the game does not modify the contents of a safe location.

Solution 4:

To the best of my knowledge, the safe containers in the Thieves Guild are:

1) The side table and guild chest next to the the one bed you can sleep in. I believe the area is yours. I've left my extra loot in these two containers since joining the guild and they've retained their contents.

2) The weapons rack near the grindstone will keep weapons. Based on leaving some Ancient Nord weapons.

3) Some of the cupboards and end tables, other members' guild chests, may be good as well. The two I've used so far are the end table next to the alchemist table and the cabinet that appears nearest my area as the guild upgrades. The 2 chaurus eggs in the end table and the stacks of food in the new cabinet were good for at least several ingame days, though it appears 30 days should be tested. I even stored some ingots, a potion and a falmer shield in the shelves of the cabinet and they remained even after some lanterns popped in the shelves on top of them. (Though I don't know if that's a good thing, that the shelf populated new stuff, I attribute it to the final upgrade with Guild Master as that's when they showed up and not a refreshing of the container.) I know some of the original cabinets will repopulate with items after a period of time though many stay empty. Although I'm not as sure about these containers as I am about ones above, I believe the ones that stay empty are good.

The ones I don't think would be wise to use are the tribute chest, the practice boxes in the training room, nor the end tables and cabinets that repopulate. The practice boxes will repopulate, at least earlier on.

There are safe containers in the apprentice quarters in the College (end tables and wardrobes, not the barrels) and all the containers in Dawnstar Sanctuary are good. I've left torches lying around in both the Thieves Guild and Dawnstar Sanctuary and they've remained as well.

As a caveat, I should say that I tend to visit these spots pretty regularly and that might help in preserving some of these containers. I pretty much use whatever is closest to drop off my loot, including the 5 houses, the Thieves Guild, Dawnstar Sanctuary, and Winterhold College, with each spot specializing in something. I recall the containers in the Blades headquarters being good as well. I'm not sure I've gone a full 30 days (if that's what it takes to be certain) without visiting any of these places but I've gone at least 2 days without visiting all of them and they've been consistent through 2 playthroughs.

My opinions are based on researching http://elderscrolls.wikia.com/wiki/The_Elder_Scrolls_Wiki and http://www.uesp.net/wiki/, tempered by my own experience. I'm on the Xbox.