Understanding Metal Buildings: A Comprehensive Guide

Key Components of a Metal Building

1. Primary Framing System

The primary framing system is the structural backbone of the building. It typically consists of rigid steel frames, columns, and rafters designed to handle dead loads, live loads, wind, snow, and seismic forces. These frames are engineered specifically for the building’s location and intended use, ensuring long-term structural integrity.

When building with metal tubing, the primary frame includes base rails, legs, and a webbed truss system. There are many designs to consider when accounting for width. Your trusses will always represent the width measurement, while your base rails represent the length, and your legs represent the height.

2. Secondary Framing (Purlins and Girts)

Secondary framing supports the roof and wall panels and helps distribute loads to the primary frame. Roof purlins run horizontally across the rafters, while wall girts provide lateral support along the exterior walls. Proper spacing and gauge selection are critical for meeting code requirements and ensuring panel performance.

The purlin used most commonly with metal buildings is referred to as "hat channel." It is a rigid 14-gauge bracing usually cut into lengths ranging from 10' to 32', with 35' being the maximum lengths we can safely travel with on our install trailers without further modifying or complicating the building systems. Our girts are essentially 14-gauge square tubing, which generally measures 2.5"x2.5". This is very durable and meets the standards for most residential garage and storage installations.

When accounting for higher snow loads or wind loads, the design requirements tend to change. Using 12-gauge tubing, a more durable, compact choice with a measurement of 2.25"x2.25", offers much higher tensile strength. This option can withstand harsher conditions and is ideal for any structure navigating potentially difficult weather. In most home applications, it will likely be a requirement, with 4' centers also being an extremely popular upgrade. Generally, a standard metal building is built on 5' centers, measured from center leg to center leg.

3. Roof and Wall Panels

Metal panels form the exterior envelope of the building. They protect against weather, improve energy efficiency, and contribute to the building’s appearance. Panel options vary by gauge, profile, coating, and color. Selecting the right panel system impacts durability, insulation compatibility, and maintenance requirements.

While horizontal panels may be cost-effective, the vertical profile is far more durable and built for longevity. This is where considering your project and its intended use becomes crucial. A garage's requirements differ significantly from those of a living dwelling. Often, the requirement to bring in architects for commercial jobs and engineers for barndominiums arises due to local codes and statutes.

The best place to start will always be your building department. They know the specific codes and ordinances required for your jurisdiction. Differences in elevation can mean varying requirements from one parcel to the next. Always consult with your building department before starting construction. There are often fines or penalties for building without proper permits, and losing an investment without doing your homework is never ideal for your wallet or your family.

4. Insulation Systems

Insulation plays a major role in energy efficiency, moisture control, and occupant comfort. Common systems include fiberglass insulation, rigid board insulation, and spray foam. The correct insulation choice depends on climate, building use, and local energy code requirements.

The most important thing to consider is the material being used and your building department's required "R" rating. Insulating can be expensive, so don't double your expenses based on someone else's recommendation. What may be ideal in North Carolina may not be sufficient in Pennsylvania, or any location for that matter. Always consult with local professionals or department figures, as they have experience in their respective fields and can guide you in the right direction.

5. Foundation and Anchoring

A metal building is only as strong as the foundation it rests on. Foundations must be engineered to support the building loads and resist uplift and lateral forces. Anchor bolts, embedded plates, and slab design must align precisely with the building’s structural plans to avoid costly issues during erection.

NEVER POUR CONCRETE WITHOUT CHECKING WITH YOUR BUILDING DEPARTMENT. Nothing stops a steadfast project faster than doubling your investment in concrete without proper permitting. If it is not required in your area, always follow the manufacturer's recommendations. Generally, this will be 1'x1', but always take your frost depth into account.

6. Openings and Accessories

Doors, windows, skylights, vents, and framed openings are integral to functionality and code compliance. Overhead doors for equipment access, storefront systems for retail use, and ventilation components for airflow must be planned during the design phase to avoid structural modifications later. If you intend to do plumbing, electrical, or radiant heat, you need to start well before concrete is planned, as these trades will require coordination.

Important Things to Consider Before Building

Site Conditions and Local Codes

Every site is different. Soil conditions, topography, wind exposure, snow loads, and seismic risk all influence building design. Local zoning regulations and building codes dictate setbacks, occupancy classifications, fire ratings, and insulation requirements. Engaging professionals familiar with local permitting processes can significantly reduce delays.

Intended Use and Future Expansion

Clearly defining how the building will be used is essential. Storage, retail, manufacturing, office, or mixed-use buildings each have different structural, insulation, and life-safety requirements. Planning for future expansion—such as longer building lengths or additional bays—can save substantial costs down the line.

Energy Efficiency and Operating Costs

While metal buildings are cost-effective to construct, long-term operating costs should not be overlooked. High-performance insulation, proper ventilation, and energy-efficient doors and windows can dramatically reduce heating and cooling expenses over the life of the building.

Fire Protection and Safety Systems

Depending on occupancy type, fire alarm systems, sprinkler systems, fire separations, and rated assemblies may be required. These systems should be coordinated early with the building design to ensure compliance without redesigns.

Engineering and Professional Design

Site-specific engineering is not optional—it is a critical investment. Properly engineered metal buildings account for local loads and site conditions, reducing risk, improving safety, and ensuring the structure passes plan reviews and inspections without costly revisions.

Final Thoughts

Metal buildings offer unmatched versatility, strength, and value—but the success of the project depends on informed planning and quality design. Understanding the key components and considering site conditions, codes, energy efficiency, and future needs will lead to a smoother build process and a better long-term outcome.

Partnering with experienced professionals who understand metal building systems and local requirements ensures your building is not only cost-effective but also compliant, durable, and built to perform for decades.

For more information on custom metal structures, check out Meta Built Buildings LLC.