You will also need WeeAlbet’s mod to increase the limit of elevators you can place, since the game only allows you to place one by default. Do NOT place more than one shell on a regular lot or place shells on penthouses/apartments. For them to work you need to place ONE shell along with regular elevators. For each model and height of elevator there are two types: a shell and a regular elevator. This works by having one of the elevators act as a shell (in CL buildings this is not needed as the building is already the shell).
Thanks to DarkWalker, who discovered how to make the elevators functional on regular lots, I was able to make these, so all the credit goes to him.