Land will cost money, depending on what you do with it, the price could be different. For instance, farmers might be charged considerably less for land, in edition to being able to rent land from the nobility (if its a feudal system). In fact, all that they might have to pay would be a tax on the yield. More on that later
Anyway, we\'ve all played strategy games, some even 3d, so we now placement on the terrain isn\'t to terribly difficult, and shouldn\'t require individual attention, if the engine is in place for it. Here\'s how it would work. You would go to the local town office, and look at available plots zoned residential. Note: it could just go raw acreage but no town would every sell you land in odd shapes. The land would always have some road frontage, or be parceled out in nice neat squares. Anyway, from that you would travel out to the area and look at perspective plots until you found one you liked, then stake a claim with marker flags at the edge (note, since the plot shape is determined by the game, this would be simply accepting that plot from the NPC at the town office) then proceed to contact an architect for a building plan. Once you find a building plan you like, go to the town office again, and get a building permit for a few (perhaps even a real life fee?) for the building, which would depend on the ostentatiousness of the structure. Once thats down, march you body down to your property and place a marker for where you want it build. When you do this, a sort of shadwon building should appear (only to the land owner) so he can see what it looks like. By walking around the flag, the orientation would change. Placing a second flag would fix the orientation. At this point, it would still be reverable. When it all kicks in is when you start to build. Even then, you still keep the permit and plans, just lose any time and money on building up to the point you stop.
Now, in RTS games, the building of buildings (har har) is displayed as a series of incomplete steps on the way to a finished product. That would be simple enough. Maybe a half dozen steps per design. Each house would require a certain amount of raw material, and a certain amount of \"skill\" points, representing the application of craft to the construction. For instance, a small house might require 300 points of stoneworking skill for the foundation, slate roof, and doorstep, and 500 points of carpentry for the rest of the house. Perhaps 200 points for glassworking to make the windows. Interestingly enough, the house could also require 200 units of glass, 500 units of wood, and 300 units of stone, though perhaps that is to simplistic. Anyway, the level of skill the artisan building it has is applied to both the amount of material used, the time taken to make, and the durability of the house. Hence, a poor craftsmen might take alot more material, and make a house that has a leaky roof after everyrain (takes damage).
A more complicated version would require 250 units of granite for the foundation and steps, and 50 units of slate for the roof. 200 units of yellow pine for the support timbers, and 100 units of oad for the floors, and another 200 units of softwood (any type) for the rest of the house. It really depends on how complex the other crafts are. Until they are determined, the complexity of building a house is undefined. Either way, the skill use and construction would be simple, just the material list might get long, which isn\'t necessarily a bad thing. If you have to trade with different towns to get what you need, thats not bad. What this would mean is there is a physically limited amount of space around towns and cities, and the price will go up as land availability goes down, and also depending on location i.e. if your neighbors are living in palaces, you are going to need that kind of money to get the land, and won\'t be able to get a permit for a hovle.
My 20 coppers