A building's dimensions are established by measuring the distances around the outer surface of the exterior walls depending on the dominating section of each wall. The measurements include the width and height of a room or area. These dimensions are important because they affect how a room is used. For example, wide rooms are usually considered to be public spaces while narrow ones are private. The same principle applies to heights: high rooms are considered public, while low ones are private. The outer dimensions of a house are also important because they determine how much floor space there is inside. Ceiling heights and door openings also play a role in this calculation. If a house has two floors, then the first thing you should do is measure the exterior dimensions of the building. You will need to know the width of the house, the length from front to back, and the depth (height) of the house. You can estimate the volume of a house based on its surface area. There are many ways to do this, but one simple way is to use the formula Volume = Surface Area x Height. For example, if you estimate that a typical two-story house is 100 feet long, 75 feet wide, and 45 feet deep, then it has an estimated volume of 450 cubic feet.