Mons Electi wasn't built by Tremere... Alexei knows who, or has a name, and he acquired it in 1221, IIRC in Mach of the Primii.
And I describe the character in this thread.
"Praxiteles can build the bath house, but you need to do something regarding the heating and cooling of the water, as those are outside Praxiteles capabilities. Do you have suitable marbles available for use in the construction?"