Interesting idea. I don't think I'd do a trapezoidal shaped window though. What about a large window that mimics the shape of one of the glass doors? Either that or a long window at the top of the wall so that you could place a buffet beneath it. I would remove the angled ceiling as a factor and work with rectangular shapes.

Excuse the pitiful mockup, but just for an idea... (I think it should be a bit wider than this depiction)

I don't think I would add a window but if I did it would not be a trapezoid one. It would be one more like that in the mockup that Ida did.

Having the window wider than the skylight throws things off for me.

One thing you have to consider is how the house would look from the outside. I think the trapezoid window is okay from the inside, but it may throw of the symmetry of the exterior or otherwise look awkward. We would need to see the exterior wall and how adding the window would change its look.

What’s on there outside of that wall? Are you thinking of a high window because of privacy or because the view isn’t that great? We rented a house with a room with high windows and it felt almost worse to have windows you couldn’t see out of... Get a lower window, and make it a traditional shape, or just go without.

IMO a huge piece of art can make you feel like you are outside and I agree a window you can’t see out of would make me crazy. Spend the money on a mini split system for air conditioning that just looks tacky on that wall.

I have high windows that I cannot see out of, and I like the light that they provide while also preventing anyone from being able to see inside. You don't get much of a view from a skylight, but you do get light, which is what she wants. If there are trees outside, then she may get a view of those.

I don't know why that side of her house has no windows, but there might be a reason for this.

OP, I don't see any windows on that wall at all.

Is it possible that the wall is a zero lot line wall and no windows are allowed? Check your survey to see and your HOA if applicable.

If you have privacy, and the direction of the light doesn't require window coverings, I think a window would look fine. But I would make it even lower, so that area is almost like a sunroom. However, before I spent that much money on the window, I would look at updating your kitchen.

Thank you for all your comments and suggestions!
I would to answer several of your questions:

• kitchen - yes, we are in the process of remodeling, it will still be open concept with a nice island between the kitchen and dining table.
• wall Ac - also will be removed and a ductless/split unit will be install (the new slim Mitsubishi), but only once I fishing construction the level below the dining room (garage + basement)
• decor: we don't like the ceiling drum either. once we finish remodeling the kitchen and other things, we are planning to buy a new dining table (92" live edge style), new chairs and new ceiling light.
• window limitations: I don't think there's any... from the house to our property line we have about 20 to 22'.
• window height: my idea was to it to be high enough to give us privacy when we are sitting at the table but once standing be able to look at the woods. because the house sits higher than the neighbors, it doesn't need to be too high to offer privacy. in my drawing (initial post) I used the height of the wall painting (airplane) to set the beginning of the window.
• outdoor - I share some of your concerns about how would it look from the outside... please note that the level below our dining/ loving room is our garage and it doesn't make sense to have windows there, mainly because we need the walls for shelving/storage etc.

I'm adding some more pictures to help you have a better idea.

after seeing this, is your opinion the same? or do you have other suggestions?

thanks a million!

It could be fun to do this, but think about how it will look when it is dark outside. Would you want a big dark glass looking at you, or would you do some sort of window covering? This might impact the spare/uncluttered look that you have now.

Yes add a window. (To me, not having a window at all on the side of a house means cheap tract builder. Not necessarily the case, but that's what it evokes to me.)

If you do not need to have it be an operational window, and if you don't need curtains for it, I like the trapezoidal shape.

After seeing photos of the exterior, I would add a rectangular or square window in any size you'd like. The trapezoid doesn't fit the style of your home.

After seeing the exterior photos of your place, I think a set of these in both the dining room AND in living room would look great. What do you think?

So that the outside would be symmetrical, I'd add two rectangular transom-style windows-- one in the dining room and the other in the living room where the airplane pic currently is.

But with windows set so high in the wall (which is nice in the right place), you'd miss the view -- and couldn't really see what's going on outside, except clouds in the sky I guess.

I like the idea of the window on this wall, but I might opt for a triple casement like on the front of the house- likely much cheaper and easier if you ever decide you need window treatments. The trapezoid does emphasize the volume ceiling...

Well, you definitely don't have zero lot line there! That's a good thing :)

I would not add a window. I would add a killer piece of art. If you add a window, you are losing valuable wall decorating space. Art can change. A window cannot. I would add art.

I would sooooo add a window, but I'd probably want to see out of it. How about a large square/rectangular window that can be opened etc. with a smaller triangle on top that can't be opened?

A rectangular window, definitely not trapezoid. It looks like theres a pipe there (plumbing stack vent?) would that interfere with placement? You may have to move the a/c to do transoms like others suggested, but they would look nice too.

the pipe can be moved, it is from our radon gas removal machine. i

I don't care for the trapezoidal window, but after seeing the outside and the extra photos, I'd put a window in, assuming that side of the house faces a favorable direction. I'd also try to get a window into the kitchen design, if possible.

Are you sure one window runs $5,000-$5,000? I'm not experienced enough to know, but that sounds like a lot of money. I would not be worried too much about privacy, with that kind of distance between the homes. Can landscape help with that? If not, then many types of window film and blinds/shades can take care of that issue.

So you can’t just add a window without adding a lintel to hold up the material above the window. That’s why a new window installation gets expensive

I would add a rectangular window and one in the living room too IF that is not a west facing view. If it's west facing forget about the windows because that will bring so much heat into the house in summer as well as afternoon glare, it will be uncomfortable.

"If it's west facing forget about the windows because that will bring so much heat into the house in summer as well as afternoon glare, it will be uncomfortable."

Wouldn't the trees help with that? In the summer, the trees will be covered in leaves, so the light from the west would be diffuse. In the winter, the trees are bare, but one might appreciate the light and the extra heat. Perhaps it depends on the location. Those trees are quite close to the house.

I admit, I like a trapazoid window. I think every house should have something a little off the mainstream to make it unique. A trapazoid window looking into a bank of fluttering leaves would seem pretty special. It's whimsical and would really bring nature in. I'm not sure about placing it that high though because then it looks uninentional to me. I get the need for privacy, but maybe a triangle window with a full sized rectangle window below it which you could put a blind on for privacy when necessary? A triangle window would still be cool and it would be a celestrial triangle window.

I don't think a trapezoid window would make sense when taking into consideration the rest of the house's architecture. Other than possibly your one angled ceiling, nothing else about your home (from what I can see in your pics) says "ultra-modern", which is the type of home befitting a trapezoid. Instead, a high level rectangular window as IdaClaire mentioned or especially the kind that misecretary suggested would look much better. Emphasizing the angular aspect of the room with another angle would be a little much, imo.