These concern the comfort and functionality of the structure. Failure here is annoying, not deadly. Duggal stresses that many modern structures fail SLS before they reach ULS. Key checks include:
No structure stands without connections. Duggal dedicates extensive space to comparing: limit state design of steel structures by sk duggal
One of the reasons for the book's popularity is its logical progression. It is structured to take a student from the fundamental properties of steel to complex structural systems. These concern the comfort and functionality of the structure