It is important to understand the way exterior walls are constructed because it can help us design good performing walls, where the wall system keeps the water outside the building, and help keep the interior temperature inside. It is also important because it we can get a better understanding on how water effects the performance of the building like how it deals with water, the transferring of loads, and maintains interior temperature. There is complexity with the different components in the wall system because all the members of the system as an important role, for instance the lintel has to distribute the compressive loads into the sides of the opening such as a window or door its above.