How to save money with structural design

A simple example of insufficient structural design is when neglecting the effect of haunches at rafter ends. Here is an example of the consequences that this could reflect in the project's budget.

Frame elevation with haunches - steel design ratio.

 

Frame elevation without haunches - steel design ratio

Warehouse dimensions: L/B/H=50.00/20.00/7.00m

Grid spacing: s=5.00m

Rafter section IPE 360 vs IPE330 (S275)

57.10kg/m vs 49.10kg/m

Steel weight increase (57.10-49.10)/5=1.6kg/m2

For steel cost 1.50€/kg, Total cost increase 1.6x1.50=2.4€/m2

For warehouse of 1000m2, total cost increase 2.40x1000=2400€