Cost to Build
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.
The Factored Square Foot Method
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.
Examples
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.
The Multipliers
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 = 0.80
Attached garage, finished and conditioned
Multiplier = 0.70
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
Crawl space area, sealed and conditioned
Multiplier = 0.2
10' and taller flat ceilings (9' ceilings are standard)
Multiplier = 0.15
Cost Per Factored Square Foot
Today we find that a quality custom home designed and built by S&R starts at about $350 per factored square foot (sometimes less if there is significant finished area in a basement) and can sometimes exceed $400 per factored square foot, depending on site complexity, specialty inclusions such as swimming pools, and premium finishes or features.
What To Expect
What makes one project cost $350 per factored square foot while another is $400? 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.
From $325 to $350 per factored square foot:
You can expect:
- Best building practices regarding structure, water tightness, and energy efficiency.
- High quality, low U-factor windows, such as Marvin Integrity, Jeld-Wen Siteline, Pella Lifestyle, or Anderson 400 Series; all are wood frame windows with low maintenance exterior cladding.
- 2X6 wall construction with a green building certified Grade 1 level insulation and sealing package.
- Lifetime warranty GAF or equal roofing shingles.
- Poured concrete or Superior Wall foundations, insulated according to NGBS guidelines.
- Enhanced foundation waterproofing practices.
- Engineered floor joists and durable resource efficient sheathing materials.
- Pre-finished fiber cement siding
- Custom built-ins and millwork details.
- Solid hardwood flooring in the main living areas, with carpet for bedrooms and LVT for baths
- Solid wood kitchen cabinets with level 1 granite tops.
- Sound dampening insulation at all bedroom, bathroom, and laundry room walls.
- Solid core hardboard interior doors with Emtek hardware, and nicely profiled trim.
- 18 SEER, or higher, heat pump system, properly designed for comfort and efficiency.
- Fireplace (wood or gas) with attractive detailing.
- Wired for technology, including user-ready wifi throughout the house, and a basic security system.
- Exterior porches, incorporating pressure treated materials, flashed deck joists, and attractive detailing.
From $350 to $375 per factored square foot:
You can expect all of the above plus:
- Enhanced fenestration specifications.
- Upgraded insulation system using spray-in-place foam and sound isolation throughout.
- Upgraded finish roofing specifications.
- Stucco, stone, brick, or cedar shingle siding for portions of the exterior.
- Upgraded kitchen with semi-custom cabinets, Level 3 countertops and high-end appliances.
- Solid wood or MDF interior doors.
- Solid wood flooring throughout the house with ceramic tile at all baths.
- Upgraded interior trim details including expansive mouldings and wainscot paneling.
- TIMBERPEG post and beam construction for portions of the house.
- Dual-fuel or Geothermal HVAC system with multiple zones.
- Ducted dehumidification system, Energy Recovery Units.
- Fireplaces in multiple locations with upgraded detailing.
- Upgraded light fixture and plumbing fixture budgets.
- Upgraded security system features, including cameras and intercom.
- Central vacuum and other upgraded low-voltage systems, such as surround sound and home theater.
- Upgraded porch and deck detailing using masonry, or either synthetic or exotic wood decking.
From $375 to $400 per factored square foot and beyond:
You can expect all of the above plus:
- TIMBERPEG throughout the house, if desired.
- Radiant floor heating or more sophisticated HVAC system.
- Metal, cedar shake, or synthetic slate roof.
- Custom cabinetry and more built-ins.
- Custom closet interiors.
- Larger budgets for plumbing fixtures, lighting fixtures, and other fixtures.
- Lightning protection and other specialty systems, including photovoltaic solar, smart house technology, or elevator.
- Stucco, stone, brick, or cedar shingle siding for the entire exterior.
- More design complexity and more complex roof systems.
Trade-Offs
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.
