I was wanting to start a demolition company and need to know what legal obligations that have to fulfil BEfore I start to bid work for customers?

Hi, R_Zais!

Yes, you would need insurance.

I'm not sure about all of Illinois, but what's on following sites should give you an idea of some other possible requirements.

Demolition Permit Requirements, Village of Wheeling, Illinois

Demolition, Project Requirements, Des Plaines, Illinois (IL)

There are also some 800 numbers on those sites that you could call.

Thanks!