Solver doesn't return a result

Hi,

I've tried running solver as per the picture below

Wall Design Issue.PNG

It claims it has run but I know it hasn't because the value doesn't change and when i manually change this value i can get a better min for cell T5 than it does.

If anyone is a legend and manages to help with this I was wondering if anyone knows how to run this sames solver operation for each cell in the range T5:T86.

I've attached the worksheet if that helps.

Cheers,
GC