Often when you look at a new home, or talk to a builder about the rough cost of building a house, you will hear the phrase “Square Footage” and they will talk in terms of “Cost per Square Foot.” This is the standard way of describing the size and cost of a house. But how to you determine the square footage of a house? You may think you can simply calculate the area of each room, add the totals together, and you have it. But, you need to be sure that you are talking about the same areas as your builder. Most of the time when builders talk about the cost per square footage, they are referring to the cost per heated or air conditioned spaces. This does not include the garage, or an unfinished basement. But that is not all you need to include in your calculation of your house’s square footage.
The total heated square footage of a house includes not only the area of each room or space, it also includes the area taken up by the interior and exterior walls. To determine the overall square footage of an existing house, you need to take an overall measure of the outside walls of the house. Halls, closets, bathrooms, all are a part of the area measured, as long as the ceiling height is over seven feet. Don’t forget the stairs. They count as part of the floor to which they descend.
You may be interested in using my “Your Perfect House Size Calculator,” which can help you plan and keep track of the room sizes you want. This “fillable-form” calculator tallies up the overall size of your planned house automatically as you list the rooms you want, including a “waste factor” for wall thicknesses, so you can get an estimate of the total square footage.
You can then enter a “cost per square foot” figure into the calculator to see what your house might end up costing. If you end up above your budget and need to change the sizes of the rooms, the calculator will automatically update the totals. It provides an easy way for you to find the combination of room sizes that will fit within your budget.
So how do you know what figure to use for the “cost per square foot?” I suggest talking with a local builder or two who constructs homes on the level that you would like. He should be able to tell you the approximate cost per square foot of homes he’s built with a similar in size and level of finish as the house you have in mind. Be sure that he is calculating the square footage the same way you are and he’s not including the garage or porch areas, etc. in his cost per square foot estimate. Every now and then I run into a builder who adds in these unfinished rooms to make his “cost per square foot” end up lower. You want to be sure you are comparing apples to apples!
To get a Your Perfect House Size Calculator, Click Here.
This “cost per square foot” estimate and your list of rooms and sizes you want will get you started on your planning. You will know that you are heading in the right direction regarding your budget. Later, you will be able to get a more accurate estimate once you have your preliminary plans, site plan and elevations. Keep in mind that the cost of appliances, finish materials, fixtures, and site improvements may make a difference in your overall cost without adding any square footage, at all. But at the outset of your house planning, this rough estimate based on cost per square foot will help you decide whether you are really in the right range, or if you need to re-think your wish list.