I wouldn't give the architects/engineers too much credit for understanding the future of their projects.
Or maybe plans get laid with future in mind, then money runs out halfway through and no one is left to take the responsibility for pie in the sky ideas.
Case in point: There is a concrete U-shaped office building in Victoria BC that has cantilevered window boxes 360 degrees all around. Filled with soil, they stick out 18" and are 12"deep. Not so structually challenging. Planted with a sprawling variety of Contoneaster and Mahonia.
Birds love this stuff. They eat, they poop. Now there are bird gut stratified seeds of every damn thing you can imagine in there.
Every gentle breeze has blown in dandelion seeds, the whole building looks a mess.
The building windows are sealed, there is nothing you can do from the inside except watch the weeds grow.
When we were contracted to weed and prune the dream gone nightmare, we went up on the roof and there was nothing, nothing to tie into!
We were told that since the glass was recessed due to the planters, no need for roof access, the glass would stay clean.
Fortunately, the building was only 4-5 stories, so almost half of it was done from a bucket truck.
But for a big chunk of it, we had to hang a pulley off of 5/8ths strapped around A/C units, and climb off that.
It was a bit sketch, A?C units are intended to stay put, that bolt is stout, rated for what, but none of us could figure a better way.
How the designers of the building thought their fifth floor planters would be maintained, I have no idea.
And frankly, neither did they.
Northwind