Santa Lucia station take vaporetto line 1 (Grand Canal) or line 5.1 (speed) and get off at stop S.Zaccaria, then follow the map to Ca 'Isidoro 10 minutes walk.
Marco Polo airport:
Boat Alilaguna Blue stop Ospedale (40 minutes), stop S. Zaccaria (90 minutes) then 10 minutes walk at Ca 'Isidoro
To get from Treviso airport :
bus ATVO to P.Roma and then vaporetto line 1 to stop S.Marco-S.Zaccaria stop then
follow the plan after 10 minutes walk to Ca ' Isidoro