Indemnity policy for an extended driveway without planning permission

Enquiries returned by our solicitor mentioned that there is no planning permission for the extended driveway. The seller has mentioned that they do not have any such permission. The work was done 7 years ago. In this regard, our solicitor has requested for an indemnity policy to be in place before completion. Is it something normal?? Do I need to add anything additional to this policy?