LIKE WHAT I POSTED EARLIER.
Why not just make it upgrade into a different building like this.
Go to object editor.
Find "Techtree - Upgrades To"
And add the building you would like it to upgrade into.
Ghan has said he has fixed this. Monovertex please confirm this fix. This was only a problem with people that had signatures in the upper levels like not the special members but the respected members.