If you're playing OFP version 1_46 then use the "CamCreate" command:
Code is:
MyHouse = "Houseafdum_mesto3" CamCreate (getpos T1)
...where "T1" is the name of a trigger (in where you could put the code).
Not all buildings have underscores though.... some use "Dum03" Dum09" etc.
It's the CLASS NAME we must use (not the model name) of a building/vehicle.
In OFP 1.75+ most people use "CreateVehicle" instead of "CamCreate"