Almost everyone that is considering building a custom home today asks the question:
How much does it cost per square foot?
Our response: “What is a square foot?”
As custom builders, our work, and the cost of our work, is not described exclusively in finished square feet, but instead, by the details, finishes, complexity and components that are not included in finished square foot measurements. Examples of these include porches, garages, unfinished basements or vaulted ceilings.
As building designers, however, we need some idea of cost per square foot so that our new design will better match the project’s budget goals. We use the “factored square foot method” to answer the cost question at the beginning stages of design.
Imagine a one-story home that has 2,000 finished square feet. It is built on a slab or over a crawl space, and has 8’ high flat ceilings, no garage, no porches, and a truss roof without an attic that could become finished space. Compare this home to another that also has 2,000 finished square feet. The second home has a full walk-out unfinished basement, a Timberpeg Great Room with exposed timber rafters vaulted to the roofline, a wrap-around porch, an attached two car garage, and a large unfinished attic with dormers that’s ready to become a spare bedroom in the future. Both homes have 2,000 square feet finished, but they are very different construction projects, and will have very different costs to build.
We use fractional multipliers to describe areas that require work and add to building cost, but that are not considered finished, conditioned square feet. The result is the Project Square Feet or Factored Square Feet. This number is a much better measurement of what the house will eventually cost.
Here are two examples of recent projects. Each began the design phase using the Factored Square Foot estimate, and the eventual contract cost landed in the mid-range of Cost per FSF.
This method of estimating is not intended to be an exact science, but it is a good predictor of total job cost. At each phase of design, we use expert budget tools to provide updated estimates, to ensure the design and budget are aligned before moving to the next design phase. Once the last phase of design is reached, S&R will provide a detailed and comprehensive line-by-line estimate to establish the actual cost to build based on the final specifications and details selected by the owners.
Finished square feet of interior living area measured from outside of building
Multiplier = 1
Detached garage, finished and conditioned
Multiplier = 0.85
Attached garage, finished and conditioned
Multiplier = 0.75
Detached garage, unfinished
Multiplier = 0.7
Attached garage, unfinished
Multiplier = 0.6
Vaulted, cathedral, or 2 story space
Multiplier = 0.5
Timber Frame area
Multiplier = 0.5
Basement area, unfinished
Multiplier = 0.5
Covered porches, breezeways
Multiplier = 0.5
Flat roof deck with railing system over finished areas
Multiplier = 0.5
Wood framed decks
Multiplier = 0.4
Terraces, patios
Multiplier = 0.3
Attic storage area, unfinished
Multiplier = 0.2
10' and taller flat ceilings (9' ceilings are standard)
Multiplier = 0.15
Today we find that a quality custom home designed and built by S&R starts at about $325 per factored square foot (sometimes less if there is significant finished area in a basement) and can sometimes exceed $375 per factored square foot, depending on site complexity, specialty inclusions such as swimming pools, and premium finishes or features.
What makes one project cost $325 per factored square foot while another is $375? Mostly, it’s features, finishes, and specifications, but it can also be design complexity. Simpler houses, with fewer corners and uncomplicated roofs, cost less. Houses with a significant finished terrace level, (aka walk-out basement) will typically be at the lowest range of cost. Larger houses almost always cost less per factored square foot than smaller houses because there is an economy of scale in custom building – houses only have one kitchen, one well pump, one driveway, etc., regardless of whether they are 1,500 square feet or 5,000 square feet.
You can expect:
You can expect all of the above plus:
You can expect all of the above plus:
The features and options listed above are just a sampling to give an idea of what to expect in a given price range. In reality, a custom home is a series of trade-offs intended to maintain a budget. Almost no one’s budget is large enough to get everything on their wish list. By prioritizing the features that are really important, and knowing how much they cost, you can pick and choose the features that will make your home special and still reach your budget goals.