(a) Except as provided by Subsection (b), a provision in a construction contract that requires the purchase of additional insured coverage, or any coverage endorsement, or provision within an insurance policy providing additional insured coverage, is void and unenforceable to the extent that it requires or provides coverage the scope of which is prohibited under this subchapter for an agreement to indemnify, hold harmless, or defend.
(b) This section does not apply to a provision in an insurance policy, or an endorsement to an insurance policy, issued under a consolidated insurance program to the extent that the provision or endorsement lists, adds, or deletes named insureds to the policy.