Here's some of my projects:
One lot will have a gallery with easels and other art studio items for imagined art classes. With the street sale wall object, it might be possible to create a art shop where random renters will paint and sell. I think the sim selling it must be in the same household (unit) as the creator, but for an exhibition it will work fine to use random works without owning the items. If a well skilled painting artist lives on the lot, he can invite a group (club) to the studio to mentor them (and take the paintings afterwards...)
One lot will have an indoor market with sales tables and fitting decor, perhaps. Any rental unit should be able to use the sales table(s), and if it is possible to run a backyard sale in a "common unit", this should also attract a few customers. Sales tables can be used on residential lots indor, but the door must be an Arch, instead of a regular Door.
One lot will have a café on ground level. I might add the barista furniture for the atmosphere, but also add a couple coffee machines for sims to serve themselves. Sims renting units (or visitors, even) can cook group meals and place those in one of those cake counter displays. Sims entering the café can then grab a free serving and a cup of coffee, to make it feel like a working café. Hopefully some renters will stop by, or my visiting sim can invite a few friends. I assume that sims not living on the lot can still visit sections of it. If visitors can not access the common unit without visiting someone who lives there, I will simply try with the ground floor not marked as a unit at all. Should work somehow :)
I have many finer homes with Servants. Anything from just one butler (live-in, not from the Vintage pack), to a small group including Butler, Cook, Maid etc. I will now let the servants have their own unit. Not quite sure how it will work, but I can switch between active units by first playing the servant preparing/serving a meal, then switch to the noble family arranging their party. Or - if the servant resides with someone, the servant(s) can be joining the lordship household during the event. By putting servants in their own unit, I will free up those 8 sims slots, which will allow for more kids or a couple mini dogs...
Some of my lots have large sections for various purposes. The largest is my royal palace which is way too big to play. Kids need 1 hr to walk from their room to the imaginary school bus. Toddlers take half a day to crawl down all the stairs... I will now see how it works with units. The royal family has a private section on 3rd floor where they spend quite some time. Making that one unit will help keeping them there without the need of locking doors. Then there is the official section on ground floor, incl Monarch's office, press room section, throne room and a few formal venues intended for events. All these official rooms might be the "common unit", or not tagged at all, if that will be less attractive to everyone on the lot. Finally the servants can get a joint servants unit, meaning they will no longer be roaming about, but appear as they are called for. I think it will be easier playing the palace when those living there will be "locked" into each their "rental units". In addition there is a "suite" that could also be a unit - stately guests and other stays there temporarily. The Landlord (Monarch) would just need to "throw an event" to be joined by the guest(s).
I'm also pondering on adding residential units on top of all my Recreation Centers. I know the centers will be hardly be visited by NPCs, but I mostly use them for my actively played household anyway, and it is not a catastrophe if the place feels empty.
More to come, surely... :)
