Can I Add On to a Steel Building Later?

Usually, yes. A steel building is easiest to grow lengthwise with matching frames, or sideways with a lean-to. Carports can often be enclosed. Widening or raising the walls is hard, so choose width and height now.

Key takeaways

• Extending the length with matching frames is the cleanest addition.
• A lean-to is the most economical way to add covered or enclosed space.
• Open carports and sheds can often be enclosed with walls and doors.
• Widening a building or raising its walls is rarely practical; buy those now.
• Keep your order details and drawings; matching frame, panel profile and color starts there.

What kinds of additions work on a steel building?

1. Lengthwise extension

The end wall comes off, new frames are added at the same spacing, and the roof and walls continue with matching panels. The roofline stays unbroken. It's the go-to for a barn that needs more stalls or a shop that needs another bay. It works best when the original end wall was planned as the "future" wall, without a large door you'd rather keep.

2. Lean-to

A single-slope roof off one or both sidewalls, open or enclosed. It adds covered equipment storage, a run-out shelter, a shop bay or a porch without touching the main roof. Snow can slide from the main roof onto the lean-to, so the lean-to is engineered for that. See what snow load does my building need?

3. Enclosing a carport or open shed

Adding side walls, end walls and doors to a steel carport or open-front shed is one of the most common upgrades. Whether it works depends on the frame: an enclosed building takes wind differently than an open one, so the frame, anchoring and openings need to be checked against the engineering for an enclosed structure. See metal carports.

4. Interior work

Insulation, liner panels, a ceiling, a tack room, an office, a bathroom: these go inside the existing shell. A ceiling or mezzanine adds load the frame has to be designed for, so check before you add one. See insulating and heating a shop.

5. New openings

A new door or window means framing a new opening in a wall that was designed without it. Small openings are usually simple; large overhead doors need framing engineered for the span and the wind.

What's hard to change later?

• Width. A wider building means new frames across the whole length, which is effectively a new building. Order the width you'll need.
• Wall height. You can't practically raise the walls of an existing steel building. Buy the height now. See how much does a metal building cost?
• Matching an unknown building. Additions are easiest when the frame style, panel profile and color are known. A building with no paperwork, or from a manufacturer that no longer exists, can be hard to match. See why engineered drawings matter.

What should I plan now to make adding on easy?

Tell us what the building might become, and we'll plan for it:

• Which end wall is the "future" wall, kept free of large doors
• Frame spacing that suits likely future door locations
• Wall height for the tallest future use
• Whether a future ceiling, insulation or lean-to should be designed in now
• Slab and conduit sleeves placed for the rooms and equipment you'll add
• Room on the site. Keep the extension side clear of septic, easements and setbacks. See where can I put a building?

Do additions need permits and engineering?

Usually. An addition is engineered to current loads and tied to the existing structure, and permit requirements vary by county. We'll walk you through what yours requires. Having the original drawings and permit on file makes it faster. If the original building was ag-exempt and the addition changes how it's used, expect the county to look at the whole building. See agricultural exemptions.

How does Rocky Mountain Metal handle an addition?

Rocky Mountain Metal sells steel-framed metal buildings only. We look at the existing building and its paperwork during the site visit and plan the addition with you. If it makes sense, we order it from 1st Choice Metal Buildings and Carports, the manufacturer's crew from Texas installs it, and we oversee the project. If your building came from another manufacturer, bring whatever paperwork you have; Micah will tell you honestly whether an addition makes sense or whether a separate building is the better move. See the buildings we offer, our service area, and request a free quote.

Frequently asked questions

Can I match the old panels and colors?

Usually closely, especially when the addition comes from the same manufacturer. A decade of sun can fade the original a shade, and careful trim placement helps hide the transition.

Is it cheaper to build big now or add on later?

Building it now is usually more economical: one order, one delivery, one install, one permit and no tie-in work. Add on later when the budget or the need isn't there yet.

Can I add a loft or mezzanine?

Over part of the building, often yes, if the frame is designed for it. Adding one to an existing building needs an engineering review first.

Can I turn my carport into a garage?

Often. Walls, end walls and a garage door can enclose a steel carport, but the frame and anchoring need to be right for an enclosed building. Bring your carport's details to the site visit.