Sean,
Thanks for your question. The cover you refer to is "damage to property being worked upon" and is normally excluded by 95% of insurance companies. The scheme we offer does provide this cover.
If you visit the site again and request a public liability insurance quote you will see the terms of the quote which confirms that cover for damage to property being worked upon is covered.
Claims have certainly been paid for such occurences. In my time I have seen a claim for £70,000 paid by an insurer where the insured damaged 50 plus panes of glass on a new commercial building, all of which were made to order and cost a fortune each. Claims for this cover are certainly paid if you have the cover and need to make such a claim
I hope this helps, feel free to ask any more questions and thank you for your comment regarding the site.
Mark