If I build a nice house for myself and then store items on shelves or it containers, can it get stolen?

I've heard items can get taken from storage chests during raids and power armor also if you leave a fusion core in it. It's best to store it in a workshop for now which seems to be the most safe place ATM till we can get confirmation.

Once GECK is released, the fallout wiki should have all the reliable info on what is safe and unsafe. Until then you/we are just going to have to take others players word for it and hope for the best as it doesn't seem like Bethesda confirm on issues like this from what I have seen.

I haven't had a raid yet, do they happen when I'm not in the base?

I haven't either but I heard they do and you get a message saying your base is under attack.

I've been raided and lost a power armor frame because I had a fusion core in one and a raider ran and hopped in it, had to kill him to get parts back. Not sure about the items bit, I recommend taking fusion cores out of any armors not in use though.

I've been just keeping the items I store in container I made myself, assuming that anything I personally make is a 'safe' container. No confirmation of that though.

I also set up the Red Rocket as my personal base and haven't invited any settlers, so it's just me. I put some turrets around also just to keep out the nosy people.

As far as I know, no. At best, they can take your power armor if a fusion core is in it (but a Settler will also get into it to help defend).

So far I've only seen power armor taken, they've never taken anything from my chests or shelves, and they shouldn't, how am I suppose to have a home in this game if no where is safe 0.0

i have only stored things in containers that i have created, and have had no problem. i have yet to have a raid, but in the 35 hours in the game, not one container has "refreshed" on me. I have even tested moving the containers in workshop mode with items in them and have had no lost items.

Well until now I have been storing important stuff in the underground shelter in sanctuary. Quite safe there.

But it is getting cluttered and full !!

I have been thinking of using Covenant as a base, it seems quite secure, Completely surrounded by walls, with gates and sentry guns.

Keys for the doors even.

I hope that I don't have to worry about my high end items and quantum nuka cola bottles being stolen, I really wanted to build my own house.

I haven't seen it happen with my items either... didn't know about the power armor thing so I will take my cores out from now on. But I have enough defenses at my two bases between anyone and my stuff where it shouldn't be a factor.... of course since I haven't encountered an attack I wouldn't know. But my Sanctuary defense power is like 140 or so and my food and water are like around the 20s... so I doubt any unfortunate raiders would happen upon the death pit that is my settlement.

Plus if you are really concerned, build a base using the floor pieces that have pylons under it which have it up off the ground and just move the stairs to your main place so no one can get into it...... Although Preston Garvey somehow got on top of one of my structures without the use of stairs....

The only place I've found spawn-free from rooftop settlers is the Red Rocket rooftop (at least so far anyway). Can try building up there and making a jump spot only you can use.

Settlers can spawn in places where they really shouldn't be able to, including on top of or inside of anything that you build, even if there's no actual way of them getting there. Unfortunately, this is also true of raiders. They spawn inside your settlements, not outside of them, so you have to make sure you have defenses spread throughout and not just around the perimeter, and building something that they can't actually get into isn't a guarantee. So far, if you build on top of something that already exists and that you can't break down yourself (the Red Rocket station or some of the houses in Sanctuary) it seems like no one will spawn on top of them. I have a staircase in storage that I use to get on top of the Red Rocket whenever I need to, and just toss it back in storage when I'm done.

Like others have said, it's impossible to know what containers are 'safe' (i.e. don't refresh their contents) until the GECK is released, after which the wiki will likely have a full list. So far in my experience it seems that any container you make yourself is safe, and I've yet to see raiders actually steal anything; they seem to exist solely to go around breaking things in your settlement until they die.

I thought self-made containers would be safe too, but then the other day... I had returned to the Red Rocket where one of my containers is stored in the garage, and dog meat ran over and took a stimpack out of the chest...

I'm thinking if dog meat can do it, so can other NPCs.

I've done this. I built a fence with no gate, but a flight of stairs that leaves anyone using it with a long jump to get to the RR rooftop. Of course I also have machine gun turrets in place to discourage overt attempts at gaining rooftop access where my house is.