Premium account says

Obtain up to 1 property (house) in the game!

 

But some forum posts talk about rent, how much is the rent, and does the house cost gold to create?

Sure allow me to clarify,

A premium account allows you to "rent" one house at a time on the game for some amount of gold. Rent in the game is more or less a tariff for living in the lands. The purpose of rent is to free up houses of players who aren't playing anymore or are not going to play for very long periods of time (several months/years).

The amount of gold required for rent is generally based on the location/size of the house you purchase (for some houses its a very small amount). A house also requires a down payment in gold to initially rent it. The recurring rent is generally a fraction of the down payment.  Rent is automatically payed approximately every 6 real days (or 30 game days) and is taken directly from your character's bank account. If the rent cannot be paid all items in the house will be removed and the house will be put up for sell again.

You can find out down payment/rent for any house by double clicking on the house sign (when near it) before purchasing/renting it.

Again the purpose of the tariff/rent is to keep the housing market going rather than it getting clogged up by older players who only login to check their houses. (Yes they are welcome to maintain their houses as long as they continue to collect gold but again we want to encourage players to stay active or allow other players to use the space essentially).