Commercial Building Works insurance
This means the property owners is reliant on the contractor's insurance to provide adequate cover. Commercial insurers will not normally cover the contract works, preferring to leave that to the contractor. This means the property owner is reliant on the contractor's insurance to provide adequate cover.
This potentially leaves the opportunity for there to be both:
At the very least, your client loses control over a key aspect of cover that they need to rely on to protect their interests in the event of a claim.