Under stair cupboard help

[Kermie88]

I’ve built an understair cupboard which is on runners and sits on a frame which is then attached. The issue I’m having is the top of the unit doesn’t sit flush to the stairs but does at the bottom which is where I measured from and wanted it to sit.

I did plan to build this out by another 18mm with plywood on the current flat white bit above of the stairs so it’s not such a big gap but the bottom fits on the drawers and the top doesn’t.

What would you recommend? Do I need to make my runner frame less deep? Is it an issue with the cabinet? Help!

I’m a newbie here and this is the first post so please be kind! I’m also an amateur DIYer

 

[ClockPie]

I made my units "sit" on a frame (screwed) that pulled out on runners, and then able to add spacers as necessary to get fine adjustment. However my front on the pull out was square and not important, just used to get perfect level (via the spacers). The final "triangle" was screwed to this as a final part....

I'll post my pics on another thread here.