Metal roofs are one of the best surfaces for solar panels: they’re durable, they last as long as or longer than the panels themselves, and they support mounting systems that minimize or avoid roof penetrations. The key is planning ahead — tell your steel building supplier about solar during design so the roof is engineered for the added load, and coordinate the mounting method with a licensed solar installer based on your roof panel type. Here’s what to know about solar panels on metal roof buildings.
Why Metal Roofs Work Well for Solar
- Long service life: A steel roof built to last for decades won’t need replacing partway through the life of the solar array — a common and costly problem with shingle roofs.
- Strong attachment options: Metal roofs offer secure mounting options, several of which avoid drilling through the roof surface.
- Heat reflection: A reflective metal roof helps keep the building cooler, and panels shade part of the roof as well.
- Snow shedding: Snow slides off metal roofs more readily, which can help panels clear sooner in winter — though you’ll want to plan for where that snow lands.
Mounting Methods Depend on Your Roof Type
Exposed-Fastener Ribbed Panels
Most steel building kits use ribbed roof panels fastened through the panel as standard. Solar mounts for these roofs use brackets that attach through the panel into the roof framing, sealed with gaskets or flashing designed for metal roofs. Done properly, they’re secure and watertight.
Standing-Seam Roofs
Standing-seam roofing, often offered as an upgrade, lets clamps attach directly to the raised seams, so panels can be mounted with no penetrations through the roof surface. It’s generally the simplest option for leak-free mounting. Ask your Building Specialist which roof panel your building uses.
Arch-Style Roofs
The curved roof of an arch-style building makes conventional rooftop solar more difficult. Owners of arch buildings often choose a ground-mounted array nearby, or a solar-ready lean-to or adjoining structure with a flatter roof.
Plan Solar During Building Design
If solar is part of your plans — now or in the future — raise it during your building’s initial design. Solar panels and racking add weight to the roof, and wind acting on the panels adds load too, so the roof framing should be engineered for them. Toro’s in-house engineering team can account for the added load as part of your building’s site-specific review. It’s also worth thinking about:
- Orientation: In North America, a roof face oriented roughly south generally produces the most energy.
- Roof pitch: Pitch affects production and mounting; your solar installer can advise on the ideal angle.
- Shading: Nearby trees and structures reduce output.
- Electrical planning: Plan conduit routes and space for inverters and electrical equipment inside the building.
- Snow: Keep doors and walkways out of the path of snow sliding off panels.
Working With a Solar Installer
Toro designs, engineers, and manufactures the building structure. Solar panel selection, system design, permitting, and installation are handled by a licensed solar installer in your area, working from your building’s roof specifications and engineered drawings. Share those drawings with your installer early so the mounting system matches your roof panel and framing.
Does Solar Affect My Building’s Cost?
Toro’s steel building kits start at $19 to $26 per square foot for the shell, with the final price driven mainly by your site’s snow, wind, and seismic requirements. If the roof needs to carry a solar array, the engineering accounts for that too, so plan it before you order. The solar system itself is a separate cost from your installer.
Permits, Codes & Engineering
Solar installations typically need their own electrical and building permits, and some utilities have interconnection requirements. Structural design loads follow the ASCE 7 standard from the American Society of Civil Engineers, referenced by the International Code Council‘s International Building Code, or the National Building Code of Canada.
Related Building Types
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Plan a Solar-Ready Steel Building
Toro Steel Buildings can engineer your roof for the solar array you plan to add. Request a free quote to get started.