Where do you live? Couch grass is quack grass in the US, but it's almost never (ever) called couchgrass. Whereas in Australia couchgrass is the very common term for bermuda. That picture could be quack grass, but it's not bermuda.

I'm from the UK

Well it looks like what we call quack grass. Does it get seed heads or flowers, and if so, can you take a picture of that?

I've no pics when the grass was high only these.

When I levelled the lawn with topsoil I had 2 patches of grass which I've ripped out as it was like the pics. I then reseeded then added compost



I'm from the UK

Your avatar appears to be false advertising, then!

BTW, I like your yard. Nice and clean, minimalist. Might be tough on the grass though on a sunny day with all that rock and brick.