Issue with new home garden - What can i do?

nickcarswell

I bought a new house 13 months ago and after only 3 months it was very apparent the garden had some drainage issues, excess waste very close to the surface of the soil, very low quality soil and to a very low depth. In August after months of to and fro the builder and the ground work company (After intially lying, saying that had been on site (Until I pointed out I had CCTV)  came to the house. Incredibly, they stood in the garden for 5 minutes. Did absoloutely no investigative work and said there is nothing wrong and they would take my claim no further. The next day they confirmed this in writing. 

I was also able to gain a report from the house builder of the soil test of mine and the joining houses. After reading that report it seems like they didnt read it first! In the report by a groundworks consulting firm there are a few things that cause concern. Firstly

" it is understood that as part of an agreed remedial approach is to provide a minimum of 600mm clean soil capping to private gardens and 300mm clean soil capping to areas of POS"  - Why is there hardcore only 8cm below soil line in this case
 "it was suggested that the soil may need to be improved and it would be recommended that advice is sought from a specialist with this regard. Post placement soil testing is understood not to be required by the NHBC" Developer were unable to provide any evidence to me this had been done.
"All the rear and front gardens Plots were underlain by compact firm reddish-brown slightly sandy gravelly clay where the gravel component was observed to comprise sub-rounded to rounded chert and angular quartzite. The depth of the lower materials was not established due to the difficulty of hand excavation." The indepdant consultancy were unable to dig, surely that proves an issue at an early stage

Today I have done a small dig and found that only 8cm below the soil the whole base of the garden within 3m of the house has an almost inpenetrable layer of hardcore / scalpings. 

Without boring everyone to death it is very clear the garden area is simply far from adequate. I have raised an complaint with NHBC 3 months ago but has obviously gone nowhere due to firstly the inclement weather earlier in the year and now coronavirus. I have carried out alot of drainage channel work at the far end of the garden and had actually instructed greenthumb to begin putting a new lawn in after the entire lawn died over the winter due to waterlogging and a leatherjacket infestation in the turf that was imported to site. 

Should I wait out for the NHBC and potentially have a dry mud garden through the summer?, Should I do the work myself / instruct a contractor and attempt to claim back through small claims court or do you have any further suggestions on how I can strengthen my position to have this resolved?

Thanks for reading and appreciate any advice that can be given.

RelievedSheff

You misunderstand the reports I'm afraid.

600mm clean capping does not mean 600mm of topsoil. It simply means 600mm of clean material which will usually be 450mm of clean site won or imported material, hardcore in your case, with 150mm of topsoil above.