What time period / setting are you envisioning these houses?
Roman urban hovels would be vastly different from a medieval rural house. There's several things you'll want to ask yourself:
1: Rural / Urban (the former will probably mean the house is slightly larger, but also accommodates one or more farm animals).
2: Level of technology.
3: Availability of raw materials.
4: Cultural and environmental concerns.
For example, coastal countries in Western Europe would usually build all their buildings with a more-or-less east-west orientation. Why? The prevailing (and hardest) winds come from the west in those countries, so you don't want to have a broad side of your house facing that direction. Also, it could become cold, so you would want your animals in your house too... not only does it keep you from freezing, but it also keeps your animals from freezing. For this same winter-problem, you wouldn't see buildings with flat roofing much... snow tends to collapse those. You'll use trees and other plants as building materials, since they are plentiful. Of course, reality is a bit more complex, but just thinking in such a way.
Personal waste disposal could be dealt with on anything from a hole in the ground to an actual toilet, depending on how people consider hygiene.
For poor people, I think however, you'll want to limit the space inside a 'house' to just one room. Also, I fear rug-removal might be in order, especially rugs this intricate. Splatter a few buckets around (for getting water) some table-ware (probably a valuable asset for people of this economic class), and some sleeping places. Furniture is quite luxurious depending on the level of poverty you're trying to achieve.
I'm not entirely up to date on the situation some hundreds of years ago in South Korea, but I would guess natural materials are building materials. I might be slapping some preconceptions around here, but I'm going to dare and bet that rice might be quite an important food source. Remember, brickwork is for those filthy rich people... That's a rule almost anywhere...