Hi anon! It makes me weirdly happy that you’re checking out Charlie’s tag…she’s such a little cutie. :) But, to answer your question, the school building is a piece of ‘hood deco, but it can be placed on lots and roads. I’m not sure if that is a feature built into the custom deco, or because I use this mod, but if you don’t have that mod already you should because it’s really useful!
Anyway, I placed a lot under the deco school and covered it with floor tiles and a bit of simple decoration to look a little more like a real community lot rather than just deco. It still is just decorative, but it looks a little nicer. And the playground is just a little lot right beside the fake school lot. I kept them as separate lots because I wanted the playground to load quickly and didn’t need my Sims walking around under the school. :P But because the playground is right next to the school, the ‘hood deco shows up and looks all school-y and neat.
Also, you might have to have your neighbourhood views/fade distance/whatever those options are called on high to see ‘hood deco from the lot. I’m not sure. Anyhow, it’s a neat little trick I learned from nepherists2, who is a ‘hood-decorating legend, and it’s a really easy way to make your neighbourhoods look more built up without actually building a whole bunch of community lots you’ll never even visit.
I hope that helps, and please let me know if I can make anything clearer for you. I’m not always the greatest at explaining things, especially when I’m tired… :)