CORRECTION: There are more spots for houses
Update #2 (October 9):
Changes are in
redCurrent Builds: Enchanting/Smelting/Crafting/Combining Room, Tree Farm (Oak, Birch, Spruce), Wanigoora Station (SRN connecting to Spawn, SRN connecting to Quasi_1987's base, spawn WIP), Donations Box, Temporary Station that connects to Spawn, Chicken Coop, OPwrecker's shop, Mall Street, Potato, Carrot, Wheat, Cactus,
Beetroot, Melon, Pumpkin, Cacao Bean Farms, Cow,
Pig and Sheep Pens,
Super Smelter (WIP but usable), semi-auto cow cooker.SRN Connected
NTN not connected
There are currently +-4 spots that you can build a house (don't quote me), If you find the city center, go north until you hit the end of all northern roads, you can build houses on the
outside of the east/west road. Just don't use up too much space - up to 12 wide (front) x 16 deep (side) on the south side and 16x20 on the north. Don't worry, plots are laid out already. My house is than 12x16 (and it's big!) so you shouldn't need to worry about your house size too much.
-OPwrecker