I think this was a bit of an oversight. It means the apartment balconies look really bare and that's a shame. It would have been good to include it as an option once the Modern Development nap is in force so once the area is upgraded and beautified you could start adding things to the balconies. It looks a bit basic as it currently stands. I'm in Pinecrest apartments now and the apartment is so small I'd have liked the option to use the balcony too. The apartments in Grims Quarry are the same. It would be difficult to address now because they'd have to extend the grid for each lot.
The building is bugged. Its not an oversight, because they knew about it since release. There's some issue with how it displays once the Modern Development NAP is in force and because of that they disabled the balconies. I think the design of the modernized building covers the balconies or something like that. Would have been nice to be able to use the balconies, as those apartments are rather cramped.
