Each house, building, or general structure has at least one load-bearing wall. When it comes to how many load-bearing walls go into a structure, it all depends on the type of support. For example, one type of load-bearing wall support formation is the basic square, where the roof lays on all four walls equally, and taking out just one of them could bring the house down. Another formation is three walls, forming a triangle. This triangle could run through a house or be the house’s structure itself. In fact, there could be just two walls as well, be them parallel to each other, or a very acute triangle, so the absence of a third wall does not hinder any balance. Lastly, there could be higher numbers than just four, but they are too many to list.
There is no real concern of having too many load-bearing walls. Instead, the concern lies in too few. Consequences of the removal of a load-bearing wall include home collapse, room collapse, or minor forms of destruction such as the cracking of wall, floor, and/or ceiling finishings, caved in floors, etc. Numbers may be crucial when it comes to load-bearing walls, but the location is where the crux lies - depending on the location of the wall, damage can either be total and complete, or minimal.
In essence, a load-bearing wall is one that helps to support its host structure, and not simply provide insulation. In other words, a wall that helps hold up the upstairs, the roof, other nearby walls, etc. is a load-bearing wall support, as it is a form of support that bears a load. Generally speaking, many homes have about two of these walls, some four, and others with everything in between and beyond. Because of modern architecture aesthetics, builders purposefully disguise load bearing walls to create a form of symmetry when symmetry is now considered to be an umbrella term for generalized, simple beauty. In the past, these walls would be a bit more obvious so homeowners would not accidentally work on these walls for the sake of remodeling. Generally, these walls have a center beam perpendicular to the floor and floor joints.
Consider an outline of a square, and note them as walls. Then, imagine there is a roof on top of the square, pushing onto the walls. If the structure is a perfect square, then the pressure is spread about evenly onto each of the four walls. Now, take one side of the square, or a wall, away - the roof should remain, correct? So, the side that was taken away cannot be considered a load bearing wall. Say another side is taken away - if a wall next to the vacant space is now absent, the roof has a high chance of toppling over, but if the wall on the opposite side is taken away, there is a good chance the roof will stay. So, to keep the roof alive, there are two parallel walls absent, and two that, apparently, are load bearing. Why are the two remaining considered to be load bearing? It is because if either one was taken away, the roof will collapse; structural damage will result from the absence of one of the mentioned walls, so they are load bearing.