The two young men, Jamie and Toby are quiet and courteous. They turned up when they said they would, did what they said they would do, replied to all my emails and tolerated my double-checking their work, and doing some of it myself (e.g. setting the lintel, rendering and plastering) gracefully and they reduced the price accordingly - very good.
The HETAS obligation is properly followed up and registered.
My only criticism is that their initial estimate is confusing because it includes mutually exclusive options (for you to chose) that are (weirdly) totalled to produce an artificially high price (the final invoice is slimmed down to the chosen items to produce the correct price) - the result of a homemade invoicing program, I think.