+1 Max Buildings Upgrades.. how's it work?

[Jimmymanfunfun]

Sorry if this has been addressed, I couldn't find my answer here on the forums.

I've upgraded my Blood Fortress to level 8 and it sais that I've received the +1 Max buildings upgrades bonus. It's listed in my bonuses.

I'm trying to upgrade my Electric Power Plants (they're currently maxed out at lvl 10.) So how does the upgrade work? Really confused.

[sbs2716g]

you are able to upgrade two building at a time. not referring to upgrade those lvl10 building...

[Jimmymanfunfun]

Ohhh. I had a totally different idea of what this prize was.
Okay thanks.

[Srebny]

does anyone know... is this a temp or permanent bonus ?

[Adm. J(K96)]

Its temp....

[Mark-RDS]

I believe it ends at the same time as our wonderful attack and defense bonuses go back to normal. Right after the battle for Romania.