Can not change lot type to residential apartment.

[inimini]

I placed an empty lot in bridgeport. I wanted to change the lot type to apartments but the option is greyed out. Can anybody help?

[Azfar90]

As far as I know, you cannot 'change' lot residential type as apartment.

If you want to edit existing lot as apartment lot (furnished or unfurnished), go to Edit Town, go to that lot as Build/Buy Mode, enable 'testingCheatsEnabled true' and 'buydebug on' from Cheat Menu (Ctrl+Shift+C), then you can put "Hidden Marker" orb from 'Debug (? Icon)>Misc. Objects' section at any built room, to make it hidden and work as apartment; NPC should reside that hidden room as long it has door.

Another way, if you put empty lot at any place in the neighbourhood, look at any pre-built apartment-like building in catalog and plop it in, as long as it fits with the size of the lot. Then you can edit it, without need to change Residential type since that building is already act as apartment.

You can still use above 'Hidden Marker' method to edit which part that needs to be as NPC apartment room.

[puzzlezaddict]

The Residential-Apartment type actually applies to University housing, not apartments as we typically understand them. If you want your sims to live in a Bridgeport apartment, you still need to use Residential-Regular. The Apartment type will come with roommates, which you probably don't want in this situation.

If you really do want roommates, try building something first, or changing the lot type to commercial first.