Inside of the geographical footprint of the Nodes are a finite number of Houses. For sake of nomenclature I will refer to these as In-Node Houses because it is possible to put a House on your Freehold and I do not want there to be confusion between the two. You may have one In-Node House per account per server, but all of your alts have access to your houses.
In-node housing can be destroyed if a Node is sieged and the siege is successful. If your house is destroyed, you won't lose any of the furniture that you put in the house, all that will be returned to you.
We are currently waiting to find out what happens to the things in storage at the house when it is destroyed during a siege. Right now the understanding is that the gatherables that are in storage would be lootable, but all the gear would be returned. Also we are not sure if houses can be specifically targeted and destroyed during sieges.