Comparison of optimal designs of steel portal frames including topological asymmetry considering rolled, fabricated and tapered sections

•Optimisation has been carried out for asymmetry and fully tapered portal frames.•Addition of PV panels was shown to have a minimal impact on the optimum weight.•Weight could be interpolated based on site wind speed.•Asymmetric frames weigh more than their symmetric counterparts.•Serviceability deflection limits have a significant impact on the frame weight.

A structural design optimisation has been carried out to allow for asymmetry and fully tapered portal frames. The additional weight of an asymmetric structural shape was found to be on average 5–13% with additional photovoltaic (PV) loading having a negligible effect on the optimum design. It was also shown that fabricated and tapered frames achieved an average percentage weight reduction of 9% and 11%, respectively, as compared to comparable hot-rolled steel frames. When the deflection limits recommended by the Steel Construction Institute were used, frames were shown to be deflection controlled with industrial limits yielding up to 40% saving.