New build garden worries

Iv have bought a ridiculously expensive new build from the plans with a 70sqm north facing garden. I haven't seen the plot or the house yet.

I am really starting to worry about the garden for raising a family as all I can imagine is a tiny dark sliver of grass. The size includes the space at the side of the semiD also.

Anyone have similar size gardens that can let me know how it is?

Ideally I'd like a garden shed, patio area and space for kids to play. Is 70sqm that small?