It was not until 1880 that an era of construction based on reliable mild steel began. By that date the quality of steels being produced had become reasonably consistent. The Home Insurance Building, completed in 1885, was the first to use skeleton frame construction, relying on its masonry cladding for stability.

An average commercial steel building costs between $16 and $20 per square foot, including building package (I-Beams, purlins, girts etc.) , delivery, foundation and the cost of construction.