No windows in our bathrooms, just good fans and a skylight in the master bath. Good lighting design will adequately compensate for no window. Of course, if you have a spectacular view you should embrace it.

Bringing in some natural light into the bathroom is a must!

I see your concern. I guess draping is a must as well!

I like to be able to get fresh air,through the entire house every once in a while, spring cleaning etc. I have a simple wood, custom colored mini blind, with a sensible valance for use in a bathroom. I just keep the blinds open as much or little as I want throughout the day, then totally close them when bathing. No biggie.

I voted for a window but I don't think there's a rule that applies to all situations. A big window is great for light, ventilation and views, but can also create problems such as lack of privacy, condensation, heat loss, compromises with the layout of the room, and there are ways of providing the necessities of light and ventilation without a window.

I like to keep the window open for a bit of fresh air at night. Since it's over the tub, I don't need to worry if it happens to rain - the tub will get wet....oh well! Mine has privacy glass so need to worry about privacy or window coverings.

Depends on your design. Would be good to show pictures.

I prefer not having windows in the bathroom, especially on the first floor. I do like that my bathroom door is very close to a large window in the next room, so getting fresh air isn't an issue.

For a new build you might want to consider windows high up, so you can get light, ventilation and privacy all at the same time. Here are a few examples.

A must to have a window, I like to open it in the mornings for fresh air to go through.

If I could put in a window, I would. To me, the more windows in a house, the better. I would never pass up an opportunity to add a window, but sometimes it's not possible. Unfortunately, my master bath has an interior wall on two sides, and a closet on the third side. So to add light, we installed two skylights. On the fourth "wall" we had a sliding shoji screen installed between the master bedroom and the bathroom. We put a large mirror over the sink area so when the shoji screen is open, the mirror reflects the view from the sliding door in the master (the toilet is in a "closet" so it is private, but the sink/tub area is exposed when the shoji screen is open). It gives the bathroom plenty of light and a view when the screen is open.