It's really very simple.
When you show up on the doorstep of a customer who is ankle-deep in water, they think, they expect, they want you to do all that is needed to make them whole.
You don't have to sell them or convince them to let you do it – they expect you to do it all. Everyone wants the convenience of making one call to one contractor who does it all!
So, let's tap into their assumption by capturing the Rebuild when you sign the Mitigation.
Include a statement in your Service Agreement that states, the customer retains contractor to "commence restoration and complete reconstruction." 90% of the time, your customer will smile, nod, grunt, or give some other indication of acknowledgment. Once they have, the Rebuild is yours.
Send the Work Authorization to the adjuster, and with all the kind words conveying, "I've got this. This is my job. I have a contract with my customer to do the work, so don't try to intervene." Your only remaining question is, who is going to write the repair estimate, the adjuster, or the contractor?
Don't come back a second time or with an additional form to ask, "Oh, by the way, Mr. Jones, can I do your rebuild?" Capture it in the first hour on the job.
The job is now yours, so run with it!