From the geometry. Those things have the diameter of a city block. That's the problem with those old giant arcology designs. Too much volume for the amount of outside wall. They look great in drawings.

Yes, you can have a hollow center with interior balconies. It's been tried. It fails for residential.

> Yes, you can have a hollow center with interior balconies. It's been tried. It fails for residential.

Most buildings in Budapest are set up this way and I don't see how it fails. Technically they are hallways, not balconies, but they function the same way.

I think a lot of it has to do with the size of the court yard and the height of the building. Four stories with a court yard that's as long and wide as the buildings are high? That can work. 50 stories with a yard that's 50m across? The lower levels will live in perpetual twilight.

Brainstorming here: what about light tunnels every ±5 floors that use mirrors to funnel light from outside the building into the courtyard? In theory, this would work...I think.

There are modern municipal housing buildings in Vienna that do this - mirrors for community space ilimunation during the day. :)

I Spain it is fairly common to see appartement building with a hollow center and interior balconies (but they usually have exterior balcony too).

I honestly hated this design because the hollow center was almost never getting any light, but it was getting the moist and the rain, making it look dirty almost all the time. It also act has a good way for sound to propagate. You can hear your neighbours at all time ...

When the hollow center has the size of a court, it is okay, but when it is just a few meters wide, it is truly awful.

So you’re saying that a quick glance at the diagram means that you think she was lying about the apartments having light?