When building a barndominium, beam spacing is a critical structural detail that can significantly influence both the strength of your building and your overall budget. Whether you’re constructing a compact weekend retreat or a spacious family home, the right beam spacing ensures safety, longevity, and cost-efficiency.
In this blog post, we’ll explore:
- What beam spacing is and why it matters
- Factors influencing optimal spacing
- How to balance strength with budget
- Expert tips for smart design choices
Understanding Beam Spacing in Barndominiums
Beam spacing refers to the distance between structural beams that support the framework of a barndominium. These beams distribute the building’s load across the foundation and transfer weight to vertical supports, such as posts or walls.
Beam spacing is not a one-size-fits-all number. Instead, it’s determined based on several factors including:
- Building size and layout
- Roof and floor loads
- Climate and wind/snow loads
- Materials used (steel, wood, engineered beams)
- Local building codes
The goal is to space beams far enough apart to be cost-effective, but close enough to maintain structural integrity.
Key Factors That Influence Beam Spacing
- Building Size and Open Span Requirements
The wider the open space you want (like a garage, workshop, or open living area), the stronger and larger your beams need to be—and the farther apart you can place them. However, as the beam span increases, the beam depth and material costs also increase.
For example:
- A 20-foot span with LVL (laminated veneer lumber) may require a deep and expensive beam.
- The same span with a steel I-beam might cost less and offer more strength.
- Load Requirements
Load is a key driver in determining beam spacing. This includes:
- Dead load (weight of the structure itself)
- Live load (furniture, people, equipment)
- Environmental load (wind, snow, seismic activity)
In snowy regions, for instance, roof beam spacing might need to be tighter (e.g., 4 to 6 feet) to safely support accumulated snow. In hurricane-prone zones, closer spacing can resist uplift and lateral forces.
- Type of Roof System
A barndominium’s roof system—gable, gambrel, or monitor—affects how loads are distributed to the beams.
- Truss roofs distribute load more evenly, allowing for wider spacing.
- Rafter roofs may require tighter spacing and intermediate supports.
If you plan to use the attic as a loft or storage area, this increases load and requires closer beam spacing or beefier beams.
- Material Choice
Steel, wood, and engineered lumber all perform differently.
- Steel I-beams are ideal for long spans and heavy loads. They cost more per foot but need fewer supports.
- Glulam beams are stronger than standard wood and can span greater distances.
- LVL beams are cost-effective and strong but may require more frequent spacing.
Your choice of material plays a huge role in how far apart you can place beams without sacrificing strength or safety.
- Budget Constraints
Beam spacing directly affects your material and labor costs:
- Wider spacing = fewer beams, less labor, but stronger/more expensive materials
- Tighter spacing = more beams, more labor, potentially cheaper materials
The trick is finding a balance. For example, using fewer but larger steel beams can reduce overall costs if you factor in labor savings from faster installation.
Designing for Efficiency: Practical Tips
Here’s how you can strike the best balance between cost and structural soundness:
- Use Structural Engineering Software or Consult a Professional
Always start with a qualified engineer or architect who can calculate precise load paths and recommend optimal beam spacing for your specific layout and climate zone. Skipping this step can lead to overbuilding (wasting money) or underbuilding (creating safety risks).
- Plan for Future Loads
If you might add solar panels, a rooftop deck, or a second story in the future, design your beam layout to accommodate extra weight now. Retrofitting later is far more expensive.
- Think Modular
Design your barndominium around standard beam and truss lengths (like 20 or 24 feet). This reduces material waste and labor costs. Many prefab steel building suppliers work on a modular grid system, which is both cost-effective and structurally sound.
- Combine Materials Strategically
Use steel for large, open-span areas (like a shop or garage), and engineered wood for smaller, partitioned living spaces. This hybrid method maximizes structural performance while keeping costs in check.
- Optimize Post Spacing with Beam Layout
Your vertical posts or columns must align with your beams. Wider beam spacing may require deeper or reinforced footings, but fewer of them. Discuss these trade-offs with your builder or engineer.
Cost Comparison Example
Let’s say you’re designing a 40′ x 60′ barndominium with a gable roof.
Option A: Steel Beams Spaced at 20′
- 3 main steel beams
- Large open spaces
- Fewer footings
- Higher material cost, lower labor
Option B: LVL Beams Spaced at 10′
- 6 beams total
- Smaller beam sizes
- More footings and posts
- Lower material cost per beam, but more labor
In many cases, Option A may end up being more economical overall due to savings in labor and speed of assembly—even though the material cost per beam is higher.
Final Thoughts
Beam spacing is more than just a structural necessity—it’s a major factor in the performance, cost, and usability of your barndominium. The right spacing makes your building strong and stable without overspending. The wrong spacing can lead to higher costs, wasted materials, or even structural failure.
To recap:
- Know your loads (live, dead, environmental)
- Choose materials wisely
- Consult professionals
- Design with efficiency and future plans in mind
Whether you’re working with a custom builder, using a prefab steel kit, or self-managing your project, understanding beam spacing will help you make smarter design decisions that improve your building’s performance and value.
Need help designing your barndominium layout or optimizing your framing plan? Contact us at [Your Company Name] for custom structural design support tailored to your site, climate, and goals.
Let us know what you’re building—we’re here to help bring it to life with safety, strength, and style.