Why are there so many LEGO Friends minifigs, but barely any houses? I have made about 10 families and I still only have one house.
LEGO Friends are essentially the same as minifigs when it comes to building things like houses. The main difference is the colour palette. If you don't mind that your Friends live in houses that use primary colours instead of pastels, you can just buy any regular Lego house (the Creator line has many) and put Friends in there. Previous houses from the Creator line from 2007-2010 did not include any minifigures, but current houses typically do include some minifigs. Feel free to mix them with the Friends mini-dolls or keep them in storage or give them away if you want.
You can also download the instructions for any existing model and the recreate it using Friends-coloured bricks if you prefer to use those colours.
If you're curious about sets that might be available now that feature houses, Brickset allows you to search sets tagged "house" or sets containing the word "house" in the name. You can sort the list by year of release in descending order, to show you sets more likely to be available in stores.
Some houses that were for sale in 2014: