Are there any PC RPG games that let's you build your own castle then upgrade it like Crossroad Keep in NWN2?

I'm looking for RPG games that let's me be the lord of the castle and I can upgrade it, hire staff and stuff like that. It has to be something like Crossroad Keep in Neverwinter Nights 2 where a character goes to an NPC builder and asks for the upgrades. (P.S Non-online games would be best, but if it's good and offers great game-play and a lot of options then it can be online)