Terrible lawn quality on top of building site!

About 3 years ago, my partner and I moved into a new build. I understand the lawn in the back garden was placed on top of the building site that was here prior to the property being built, so the soil underneath the lawn is very clay-like.

The grass has never been great, but we were hoping it'd improve summer-to-summer. It hasn't, and now it's pretty bare, with moss appearing.

I'm looking for the answer to 2 questions if possible.

1. What should we try prior to spending hundreds of pounds on new lawn to replace it?

2. Even if we do do the above and buy new lawn, is the real issue the soil underneath the grass?


What We've Tried Already:

Last year I used a rake to poke holes in the lawn for allowing a better flow of water (not sure if this was even useful - but didn't seem to work).

We've also put seed down, but didn't seem to make much difference. Is there a best type of (pet-friendly) seed we could try instead?


The garden gets as much sun as possible, it's very well positioned.

 

Does it water log in winter, if not, and your only looking for some decent grass, rather than a "Lawn", as such, I'd just feed it.
I see you say "pet friendly"?

 

Thanks for the reply Pete!

It does water log indeed mate, it's like marshland in bad weather.

We have a little chihuahua cross. He doesn't make any mess or appear to be able to damage the grass in anyway though. My concern is that we put something down that he might try to eat.

 

If its water logging then something needs to be done with the base, it wont matter what you do on top, if it doesn't drain reasonably well.
We are talking standing water? and not just a bit muddy?

If so it sounds to me like you need to either get someone in, or get stuck in yourself.

Obviously depending on how big the area is and how much you want to put in.