Don't know about vinyl siding hanging stuff, but I do know how to hang a really heavy weight mirror. In fact, my DH is in the process of hanging one inside our Cape up in Massachusetts now. It takes two boards, one mounted on the wall and one mounted on the back of the mirror. The long edge of the wall-mounted board is sliced at an angle to allow the mirror-mounted board to mate with it, and thus spread out the load across the width of the board. If I can draw it out for you with keyboard strokes, I'd do it. ]__\ is the basic shape. The slanted angle is on a long edge of the board. I'd make it a 2" thick board at least. The two boards come together so that the edges are like this \\ .....Hope that shows you. With your mirror, a second row of wood near the bottom might secure it against any wind trying to twist it. But basically, this will hold up a LOT of weight.

I think I will ask about that cawaps, I didn't know if it was reasonable to ask but considering the apartment is 4k a month and you can't put one hole anywhere it is really cramping my decor style. What's the point of a gorgeous flat if it looks like you have no style? I have used command hooks for a few spots (but the look is modern so less is more) but I agree, it would be a fantastic investment for the owner.

I agree @calidesign...that was our intention, so we’re trying figure out how to hang a couple of large custom portraits of our kids when they were a few weeks old in the stairwell. They are incredibly heavy and we live in earthquake country. Not sure what kind of pro to hire to hang! Maybe I’ll see how much it would cost to reframe them. Working on the window coverings, but we’d keep the windows facing the dining wall open most of the time anyway because of the view. It’s north facing and today is pretty gray and rainy, so there’s more reflection than normal, I think. Thanks

@JAN MOYER Also Jan, I had to giggle at your comment about the green bookcase. I actually just bought a leaning ladder book shelf for that side of the TV, so I would still be able to display some things (different than what's on there now), but it would open it up a little and not be so heavy, or crowded. And, because the other side has the other green bookcase, I plan on removing it also. I bought a tree and plan on working it into that space as an arrangement on that side of the TV. We have had those bookcases since my sons were babies. My youngest son came home from college over Christmas break and I told him I was thinking about getting rid of them. He shouted, "Thank you mom, it's about time!!"