1.Qualification:CE(DIN18800),ISO9001:2000, 2.Minimum Steel Quantity 3.High Construction Efficiency 4.Cost Effective:$900 We have the most advanced arched roof manufacturing facilities and CAD based "arched shell structure design analysis" softwarehou, the span of building varies from 6m to 42m. Advatage: Large span, light weight, good in appearance, wide space,rain-protection,seismic resistance, ...