No German, but to perhaps clarify for kascho.
A 4-bdr house would generally indicate a larger home, since it would imply a large living surface. Of course there would still be a kitchen, living room, dining room (or with an open concept, a combined space to accommodate those areas), possibly also a family room and a den/office. A 4-bdr home would generally also have 2+ full bathrooms, as well as a 2-piece bathroom/powder room. I would say this would probably be a middle to upper middle class home.
When selling real estate, the first thing mentioned are usually the number of bedrooms and bathrooms.
It is just a different way of addressing housing than in Germany.