Ok quick update before I finish work for the evening. I also had the contractor come over after they left.
The contractor raised his eyebrows at a few things but overall it's not a complete disaster and is salvageable. He thought the plan of using downpipes was over the top, unneccessary and not cost effective when using perforated land drainage would have achieved the same thing without him having to cut a load of slits.
There was some concern with the patio being laid on soil. I can confirm it's type 1 aggregate that has been compacted. The contracted (older guy) said he would have put a concrete base down but he goes overkill on these things so this is more than likely to be absolutely fine. The image I posted earlier was perhaps a red herring.
He also identified the acco drains as being too shallow (only 25-30mm). This may not be an issue based on the next point. Also he said he'd recommend having some shingle between the house bricks and the aco due so the bricks don't get wet from rain water splashing and getting the damp course wet.
Perhaps one of the most useful things I took away was the drainage. The guy doing the job was going to connect this in to the foul drain but the grid of pipes he has created for the turf sits below the drain. The contracter who came over identified a downpipe which may connect to the storm drain. He gave me some die to give to the other guy to test. This may solve a lot of problems and make his life a lot easier if he can tap in to that drain.
I'm actually feeling a lot better after his visit. I called the guy doing the job and told him these are the recommendations and I think he saw the storm drain suggestion as being positive but perhaps not so much the aco being shallow and having the shingle between the aco and the house bricks. He said it would collect water and it would have nowhere to go. I'm sure I saw something earlier on in the thread about angling the rain drops so I'll have to go back and check that.
Here is the progress so far today:
![kh29AWu.jpg kh29AWu.jpg](https://forums.overclockers.co.uk/data/attachments/466/466846-dc72d4ac1e741fc4ec8ffde57362447d.jpg?hash=3HLUrB50H8)