I am looking for advice and anyone who can help with regards to NHBC standards as I have a resolution meeting planned for mid May and want to be prepared.
I have a new build house on the coast that has no mains drainage and I have had issues with garden flooding since moving in a year ago. Its a bungalow with garden all around the the house. According to the developer and from what I could see their are soakaways in the ground but due to us being almost at sea level they were getting overloaded and water was leaking onto the ground.
The builder employed an engineer who suggested putting in trenches in the middle of the garden all the way around including PolyPipe which can soak up and then drain the water away via a larger pipe to a local farmers field. This has been installed and is somewhat successful however the half of the garden towards the house where the pipe is its still very damp whereas on the other side of the pipe its much drier.
Originally it was being suggested to level the land as there is quite a negative slope where parts of the garden are several feet above the damp proof course. The builder didn't do this and is now refusing to do anymore where I am left with damp always around the bricks of the house and very damp soil even after days / weeks without rain on one half of the garden towards the house.
I wanted to ask if there are any standards regarding this to be prepared for my meeting as I see you can't have water collecting up to 3 metres away from the house in particular are there any stadards regarding a negative slope as its almost like the house has been built in a dip in places.
There are two types of soakaway.
One is a pit filled with large stone called rejects.
The other, better more expensive type is a large chamber which has quite a bit of storage capacity.
Either type should work well, although the chamber can be cleaned out and maintained if required.
The effectiveness of either will depend on the ground water table. As you live on the coast, if you are close to the beach your soakaway may be affected by the tides. (less use at high tide)
I am pleased the NHBC are going to inspect this.
Ground should not be placed against the home above 150mm below dpc level.
NHBC standards also state that within 3 metres of the home the ground should not be waterlogged.
As to why the house was contructed below the surrounding ground level or why you/the builder have allowed the ground level to be increased after construction is unclear.
House builders are only responsible for work thye have done not that of others you may employ!