Extension structural issues -- legal action?

[Alevelprep25]

So, we had an extension started by a builder which came to us highly recommended. Unfortunately, throughout the built building control picked up on so many issues. I had to pay a structural engineer to come visit the site again and check. Please note this is a standard box at the back extension with a flat roof, so not a complicated built. Builder now kicked out from the job and waiting for quotes to finish the shell/correct issues. Issues were:
1- lack of packing on top of structural beam which could have resulted in the best part of the upstairs coming down and cracking (emergency repair performed)
2- joists forom existing kitchen essentially hanging on mid air impacting the structural integrity of teh upstairs (again repaired)
3- beam installed at a slight angle (structural engineer confirmed this is satisfactory!)
4- posts holding the beam either side for the knock throw fixed to rubble (engineering bricks!!) and not a solid pad foundation. These need to be removed/area dug out for pad foundations and then reinstalled (awaiting for structural engineer to confirm on teh best way to do this)
5- walls all around don't have insulation about the window/patio doors (a good 30/40 cm at the top!!)

Plus poor workmeship but these are minor compared to the above. So the question is: can you go to the small claim court for this? Are you likely to get anything out of court? Or will that be a waste of time?

Please note that this wasn't exactly a super cheap builder. Quotes similar to others received but went with this given the recommendations. If you starting anything similar, please monitor the built closely and get building control to visit at each stage rather than signing things off using pictures. The builder was insisting on pictures and continuing with plaster boarding etc. I am so glad I stopped him and we had the change to rectify things before it's all covered up!!

Also, on a related note: how much should expect to pay to finish the shell to a basic finish? Note that we still have all materials so it will be mostly labour, electrics and plumbing.

I will call citizens advice bureau on Tue, but any thoughts on the best way to approach things would be much appreciated!

Just to add, the builder closed his company last month while still working on the extension and not sure he extended his indemnity insurance!!

I was just going to post there’s no point taking the matter to small claims as the builder will shut his company down and start up again under a new name

This is classic modus operandi
In our experience you’ll get nothing

I thought that might be the case! Can I get any of the money back through the bank? Or is that unlikely too

Did you take out renovation insurance?

Not specifically, but I called current home insurance before the work start and they said I am covered for any work that's less than 75k. Do you reckon I can recoup any through insurance?

I can’t see on what basis tbh but it never hurts to ask

Poor workmanship isn’t generally covered in this type of insurance but you could use them to try and take the builders to court. ie legal cover

If the workmanship causes damage elsewhere like a fire or something then you’re covered . The insurance is for damage to your existing property by the builders

No, you should have taken out a specific all risks policy for the build.

Ah, I didn't know 😕 thanks for flagging though.