Building a house is an exciting endeavor that requires careful planning and material estimation. One of the most important materials to determine is how much lumber you will need, typically measured in board feet. The amount of lumber required depends on the size of the house, number of floors, construction style, and other factors.
Quick Answers
Here are some quick answers to common questions about estimating lumber needs:
- A typical 2,000 square foot single-story home needs 10,000 to 15,000 board feet of framing lumber.
- Add 1,500 to 2,500 board feet for each additional floor.
- Luxury custom homes often require 20,000 board feet or more.
- Multiply the square footage by 5 to 7 to get a rough estimate.
- The framing method (platform vs. balloon) impacts lumber needs.
Now let’s look at this question in more detail.
What is a Board Foot?
In the lumber industry, board foot is the standard unit for measuring lumber. One board foot equals a one-foot square board that is one inch thick. So a board that is 8 feet long, 6 inches wide, and 1 inch thick would contain:
- Length: 8 feet
- Width: 0.5 feet (6 inches divided by 12 inches)
- Thickness: 1 inch
Multiply these together to get 4 board feet (8 x 0.5 x 1 = 4).
Understanding what a board foot represents helps conceptualize how much lumber is needed for framing and other purposes when building a house.
Factors That Impact Lumber Requirements
Several factors come into play when estimating how much lumber you will need for house construction:
House Size
The total square footage of the home directly correlates to framing and decking needs. The larger the home, the more lumber required.
Number of Floors
A multi-story home needs lumber for each floor’s framing and subflooring. The number of floors is a significant driver of total board feet.
Framing Method
Two main framing methods exist: platform and balloon. Platform framing uses one floor platform at a time, with walls above supporting the next floor. Balloon framing constructs stud walls over the entire height of the house for both interior and exterior walls.
Balloon framing typically uses less lumber than platform framing. If using platform framing, add 20% more lumber for a two-story home.
Wall Height
Homes with cathedral ceilings or two-story rooms require longer studs and impact framing lumber needs.
Construction Style
Production homes use efficient framing techniques to optimize lumber use. Custom homes often have complex rooflines, intricate detailing, and higher-end finishes that increase board feet.
Geographic Location
Homes in areas prone to high winds, earthquakes, heavy snow loads require additional framing for structural reinforcement.
Waste Factor
Add 10-15% extra for unavoidable lumber cuts, waste, and spoilage on the job site.
How to Estimate Board Feet
Now that we’ve covered the key factors, here are some methods for quantifying lumber needs:
Square Footage Estimate
As a very rough estimate, multiply the total square footage of the home by 5 to 7. This will give you a ballpark estimate for total lumber needs.
For example, a 2,000 square foot home would need approximately:
- 2,000 sq ft x 5 = 10,000 board feet
- 2,000 sq ft x 7 = 14,000 board feet
The range accounts for variances in construction style and other factors. While very approximate, this quick formula provides a starting point for more detailed estimates.
Manual Calculation by Stud Count
For a more accurate estimate, calculate the number of studs needed for each wall, floor, and roof. Consider stud spacing, construction style, and wall height to determine linear feet of lumber per stud. Then multiply by the board foot figure for that lumber size.
For example, a 20 foot wall with 16 inch on-center stud spacing will require approximately 13 studs. 2×4 studs equate to around 1 board foot per linear foot. So 13 studs at 20 feet each would be 260 board feet for that wall (13 x 20 x 1).
Repeat this process for every wall section, floor, and roof to total the board feet for the entire house.
Materials Estimating Software
Specialized lumber estimating software synthesizes key measurements to determine framing, decking, and other materials. Programs like Interpid Estimator, NAHB Chart of Accounts, and DATAM Software accept inputs like square footage, wall dimensions, openings, and story heights to produce detailed takeoffs.
This streamlines the estimating process and improves accuracy. Some programs also account for waste factors and optimizecuts to reduce excess lumber purchases.
Board Feet Estimates by House Size
Here are some typical board foot estimates based on sample house sizes and a moderate 7 board feet per square foot estimate:
| House Size | Total Board Feet |
| 1,000 sq ft | 7,000 |
| 1,500 sq ft | 10,500 |
| 2,000 sq ft | 14,000 |
| 2,500 sq ft | 17,500 |
| 3,000 sq ft | 21,000 |
| 3,500 sq ft | 24,500 |
| 4,000 sq ft | 28,000 |
These are just estimates – the region, construction style, number of floors, and other factors can alter requirements significantly. It’s best to calculate manual takeoffs or use software for each unique home design.
Estimating Other Building Materials
In addition to framing lumber, estimate siding, roofing, insulation, drywall, and decking materials needed. Some key material needs include:
- Siding – Estimate the exterior wall square footage minus openings to determine siding needs. Add 5-10% for waste.
- Roofing – Roof area dictates shingle requirements. Add 5-10% for ridge caps, starter shingles, and waste.
- Insulation – Calculate exterior wall, ceiling, and floor square footage to determine insulation batts or loosefill.
- Drywall – Interior wall and ceiling square footage sets gypsum board needs. Figure 4×8 or 4×12 sheets.
- Decking – Porches, patios, decks require deck boards and fasteners. Measure the surface area.
For all building materials, add 10-20% extra for incidentals and overage on the job site.
Material Planning Tips
Here are some tips for planning and buying lumber and other construction materials:
- Get several contractor bids or cost estimates – their takeoffs help estimate materials.
- Determine availability and lead times – order far in advance for specialty lumber.
- Add a buffer for your takeoffs and estimates – it’s better to overestimate than run short.
- Factor delivery costs – materials amounts determine required truck space.
- Consider job site access – some sites limit truck sizes and offloading space.
- Plan vertical staging and storage – small lots require careful material coordination.
- Inspect deliveries thoroughly – reject damaged or warped lumber and decking.
- Store materials properly – prevent warping, UV damage, moisture exposure.
With smart planning, you can ensure you have the right amount of quality lumber and supplies on hand when needed during the build process.
Conclusion
Estimating lumber requirements is an essential step when building a house. The total board feet needed depends on the home’s square footage, number of floors, construction style, wall heights, location, and other design factors. On average, you can expect to need between 5-7 board feet of lumber per square foot of house. Use takeoffs from blueprints or estimating software to dial in the specific amount required for a custom home design. Account for 10-15% overage for waste and incidentals on the job site. With an accurate lumber estimate, you can ensure you purchase the right amount of framing, decking, and other wood materials for your new home build.
