Metal Buildings With Living Quarters: What to Know

A metal building designed to include living quarters — sometimes called a barndominium-style structure — is one of the more requested customizations Union Steel builds, especially in larger footprints like 40×60 or 50×60. The steel shell is the easy part. What actually changes the project is the fact that someone’s going to live inside it.

Why Living Quarters Changes the Code Classification

An open carport or an unfinished storage barn is treated by most building codes as an accessory structure — simpler requirements, more flexibility. The moment part of that structure becomes habitable space, that changes. Under one state’s residential code, habitable areas within a detached garage, carport, or accessory structure must meet the code’s full requirements, including an exit door or window that satisfies egress standards — not the lighter requirements that apply to a structure nobody’s living in.

That’s one state’s specific version, and requirements vary by locality, but the underlying principle holds broadly: adding living quarters isn’t just a finishing decision, it’s a classification change that brings egress, and often insulation and electrical requirements, into play that a simple storage building wouldn’t need.

What This Means for Planning

Because of that classification shift, a metal building with living quarters needs to be planned as a habitable structure from the start, not retrofitted into one after the shell goes up. That affects window and door placement (for egress, not just aesthetics), insulation strategy (living space needs different thermal performance than open storage), and electrical planning (a barn doesn’t need the same wiring a living space does).

It’s worth having this conversation with your local building department before finalizing a design — not after the shell is built — since egress and code requirements for habitable space affect where doors and windows go, and that’s far easier to plan upfront than to add later.

Structural Considerations for Larger Footprints

Sizes like 40×60, 50×60, 60×60, and 30′ x 60 with living quarters are common for these projects because they give enough footprint to separate a living area from a workshop, garage, or storage bay under one roof — the right size depends on how much of the structure is actually living space versus garage or barn space. At these sizes, roof style stops being optional in the same way it is for a small carport — a structure this large will need a vertical roof regardless of region, since it exceeds the 31-foot length threshold, and the added weight of insulation, interior framing, and finishes means the structural specification needs to account for more than an empty shell would.

Planning Yours

If you’re considering a metal building with living quarters, start the permit and code conversation early, plan window and door placement around actual egress needs rather than filling it in later, and size the structure with your final layout in mind rather than assuming you can subdivide any footprint after the fact.

Union Steel’s 3D Builder lets you start configuring the shell — size, roof style, and door/window placement — and our team can talk through the living-quarters specifics for your project from there.

FAQ

Do I need a different permit for a metal building with living quarters?
In most areas, yes — habitable space typically requires meeting additional code requirements beyond what a simple accessory structure needs. Confirm with your local building department early.

What size is typical for a metal building with living quarters?
40×60, 50×60, 60×60, and 30′ x 60 are common footprints, since they allow enough space to separate living quarters from a garage or storage area.

Does a metal building with living quarters need a vertical roof?
At these larger sizes, yes — anything past 31 feet requires a vertical roof regardless of the living-quarters plan.

Can I add living quarters to an existing metal building?
It’s possible, but it’s a significant project since it affects egress, insulation, and electrical planning — easier to design in from the start than to retrofit.