Actually I think only guilds or other organisations should be able to build anything aside from normal housing facilities. Players can make themselves a house if they could buy a patch of land.
There should probably be different quality houses like for example wooden shacks, something everyone who doesn\'t have two left hands (read one or two crafting or housebuilding skills) could put up. Then there are clay houses, which require a bit more skill and resources to build, a variety of stone, brick, marble, ... houses each increasing in resource cost and skill so that normal players have to hire a builder to have their houses made.
One could also include architects in this but I wouldn\'t use those for the normal houses, only for the more advanced buildings like guild halls, castles, stores, taverns, ... Those buildings would require a blueprint to be drawn out before builders can start creating them.
This along with only groups being able to create special buildings will reduce the ammount of those type of buildings. Aside from that I think that people should also be able to sell their houses or buildings if they want. This will create real estate jobs and make sure not everyone just starts building their own house but that unused houses circulate. That will help save the server quite some space and work.
