Duro Span offers several arch building series, and the names alone don't tell you much. If you're comparing options for the first time, here's a straightforward breakdown of the three most commonly requested series — Q, S, and G — and where each one fits best.
Q-Series: The All-Purpose Clear-Span Building
The Q-Series is Duro Span's clear-span workhorse. Its rounded arch design carries the structural load through the panels themselves, which means there's no internal framework eating into your usable floor space — every square foot inside the building is usable, wall to wall. It's the series most customers land on for garages, workshops, farm and agricultural storage, and general commercial storage, largely because it balances cost, speed of installation, and durability without requiring specialized use-case engineering.
Best for garages, workshops, general storage, farm buildings, buyers who want a straightforward, cost-effective structure without a lot of decision-making overhead.
S-Series: Straight-Wall Strength
The S-Series takes a different structural approach — straight vertical walls that transition into an arched roofline, rather than a full continuous curve from foundation to peak. That straight-wall design adds usable vertical space along the perimeter (better for shelving, mezzanines, or wall-mounted equipment) while keeping the clear-span roof advantages of an arch building. S-Series buildings are available from 16 to 60 feet wide, with varying center heights and effectively unlimited length, giving it more flexibility for buyers who need a specific footprint or taller sidewalls than a full-arch design provides.
Best for projects where perimeter wall space matters — retail or commercial buildouts, buildings with shelving or mezzanine storage, projects with specific height or footprint requirements.
G-Series: Built for Industrial and Commercial Use
The G-Series is engineered specifically for projects where function and durability are the priority: equipment storage, industrial workshops, on-site offices, and commercial applications that take daily wear. It's the series most often specified when a project calls for heavier-duty, real-world industrial use rather than general-purpose storage.
Best for industrial and commercial operations, equipment storage, workshops with heavy daily use, on-site offices.
How to Decide
A few questions narrow it down quickly:
Do you need every inch of interior width usable, with no perimeter constraints? Q-Series.
Do you need taller straight sidewalls for shelving, mezzanines, or a specific footprint? S-Series.
Is this a commercial or industrial application with heavy daily use? G-Series.
Every series is manufactured pre-cut, pre-punched, and pre-drilled, and engineered to meet the building code of the state and county where it will be delivered.
Not sure which series fits your project? Call 888-848-2011 to speak with a building specialist, or
get a free quote and we'll help you size it correctly the first time.