Our customers often ask us this question so instead of offering the usual qualitative answers, we decided to do an in-depth analysis on home cost to build based on how many stories the house is.
Obviously, 2-story houses make an efficient use of the foundation, roof structure & material, covering up to twice as much square footage as a one-story structure would. But much of that gain in value is lost because additional unusable floorspace is taken up by staircases.
Here, our methodology is to take the cost/SF or our library of one story and two story houses, while subtracting out the average square footage taken up by the staircase (~85SF/floor). All data is provided by our proprietary cost to build calculator found here. The same standard material selections and construction variables were used uniformly across the entire dataset.
As you can see, our two-story home plans are consistently more affordable to build than our one story plans. On average, our single story homes cost $260.21/SF to build while our two-story plans cost $223.94/SF, a savings of about 14%.
Another way of looking at this is: for the same price, you could build a 2,000SF one-story house or a 2,325 two-story house. That's a pretty significant amount of additional floorspace! For this reason, I'd say that two story houses are becoming underrated.
Note though, that this rule may not always hold. We displayed the data in the chart above to illustrate this fact. Many of the data points are actually really close together, meaning that the potential savings may vary depending on the individual features and layouts of the floor plan. In one pairing, the two-story house is actually more expensive per SF than the one-story home.