Bastions and level reqs

Hello,

now that we have the complete rules about bastions, I m wondering about how to manage the "level requirements" the "specific requirement" and  multi-classing.

For example, a level 9 Cleric can build a Sacristy and that's pretty "normal"... but would a Cleric1/Fighter8 be able to build one ?

RAW, I don't see anything going one way or the other...

As DM, how would you rule this ?

For a multiclass character, I'd say we should use the total character level, following how the character levels are calculated.

I agree. These sorts of things are always based on total character level unless they're class features, or otherwise specify a specific class.