New build home/Garden not complete on completion day.

dimbo61

I would get your Wellington boots on and big coat and go outside in the morning and turn over the whole ground. Pull any bricks or stones out so the soil is ready to be turfed.
If it's very very muddy with a lake in the middle you might need to sort extra drainage 

https://www.jdpipes.co.uk/knowledge/land-drainage/fixing-drainage-in-lawn.html

NinjaTune

I appreciate that it's disappointing and I agree that they should have told you earlier than they did.  Ultimately, however, that would not have changed the fact your garden would still not have been ready, irrespective of when you were informed.  Maybe they were hoping right up until completion that they might have a chance to get things done in time.

You can make a complaint to the house builders and they may decide to send you some flowers/chocolates as an apology.  I very much doubt they will give you any monetary compensation for the inconvenience but I guess you could always ask

Davesnave

Brian, they will deliver what it says in the contract, which may well contain a clause concerning delays due to adverse weather. Does it? I think they might be a bit daft if it didn't.

A new garden is exciting. After you get whatever it is they're going to provide, you may also have the excitement of finding all the things they never mentioned, like the broken bricks and blocks, great gobs of clay and endless bits of plastic strapping, all lying  150mm below the surface in compacted sub-soil. Of course, if you're just an average sort of gardener this won't be an issue, but I managed to find such things still waiting for discovery very close to the house ...and my property is 47 years old!