I've envisioned these to be packed 2-3 to a single tile. There normally isn't a lot of land between them, normally only enough to include a small area to park a vehicle, but considering the very inconsistent scale of vehicles to buildings, I don't think it's worth the bother to try to include that detail.
Ideal places to put them would be in towns with low population (under 10,000), on the outskirts of larger towns, near industrial areas that are far away from towns, near major highways, and in rural areas that have a road which connect larger population.
Inside small towns, they function as inexpensive rental property, and should eventually be replaced by apartments and small homes as the population grows. At the edges of towns they will replace farmland, as the farms are pushed further away from the expanding city, and they would be more permanent, eventually growing into a suburban district. In rural areas, highways or industry, they're often permanent fixtures that are owned rather than rented due to the low cost of ownership of the building and property.
At least, that's how I envision it all. I could be completely mistaken on how it actually works best. All my sprites are public domain, so feel free to use and adapt them as you wish. My goal is to see artists and coders get inspired to do new things, not stamp my foot and throw a hissy fit because somebody didn't do as I say
I don't know if you could include both these and the industrial apartment complexes in the same industry pack if you went by my guidelines, though. My ideas may be impossible.
). In OTTD, it would be fine to have them outside cities, but it would look silly if there weren't any roads leading to them, so maybe require adjacent road(s)?
