@Windows on Washington Ltd. So, could we still have the same problem regardless of who we go with?

Yes, no true rhyme nor reason why it happens and it happens to all IGU manufacturers.

Windows in showers are problematic for a number of reasons including shorter life expectancies for insulated (i.e., multi-pane with inert gas) glass. If you must have a window in your shower, I suggest you install a single-pane window. Yes, there's an energy penalty, but you won't be replacing windows due to condensation between the panes. Don't forget that the glass must be tempered glass given its location.

Sealed Glass Units can fail on any window and they don't have to be in a shower. We had Milgard windows in our previous house (we didn't build the house) and a few sealed glass units had failed at the 10 year mark when we bought the house. By the time we sold 10 years later even more had failed. We had the failed sealed glass units replaced before putting the house on the market.

For our new build we went with Marvin windows, which are a better window and hopefully will last longer before we get any glass failures.

@Charles Ross Homes, that is a good idea about the single pane. Outside of the energy issue, are there any other disadvantages?

A single-pane window will be more susceptible to condensation on the interior when it's cold outside. That's a reasonable trade off to eliminate condensation between the panes, in my opinion.

If a cold climate it will also make you bathroom considerable colder overall.

@millworkman We are in Los Angeles, so it may be ok.

Regardless of failed units, windows within the shower surround is always a bad idea. The sashes, frame design/extrusions, and hardware are not designed to shed water hitting it from the inside. So with your slider you have pooling water in the track which can find it's way down into the wall.

Also, many people do not understand that even opaque glass still allows a shadow show, the closer you are to the glass the crisper that shadow is, if that is a concern for you.

An alternative to retain natural light in a shower is a transom above the surround height. The window does not have to be operable if there is an exhaust fan.

@3onthetree We are in a townhouse with an HOA, so the window can't be removed. Opaque glass provides enough coverage, as the bathroom is on the third floor. I understand the problem with water hitting the inside of the frame. So, even with a high-end Marvin fiberglass window, it still won't provide any better protection from the water?

Expensive doesn't matter, you can view the section details of the Marvin sill and understand it is not designed to manage water from the interior. For the most part only storefront and glass block have the same profile inside and outside.

In my experience, a townhome in a HOA would not allow a different brand of window unless all the townhome's windows were changed. You could only repair a window by swapping in the same brand unit.

@3onthetree We are in a small HOA with only eight units in the building. They have given me permission to replace the window with something similar. Our bathroom is in the back of the building, and there is only one other bathroom window.

What are your thoughts on using a single-pane window?

" So, even with a high-end Marvin fiberglass window, it still won't provide any better protection from the water? "

The window alone is not enough. The waterproofing needs to be treated as you would the exterior side of the window. You need the water to shed away from the window.

There is no substantial advantage to choosing a single pane window, if you are choosing a frosted window. Any break in the seal and condensation will only add to the frost look and opacity desired. It won't be better or worse in performance with a broken seal.

However, if you don't water proof the wall correctly, and integrate that with the window, the water will go down inside the wall, and to the floors below. It can be a wholesale disaster without the right knowledgeable tile person. https://www.ceramictilefoundation.org/homeowners-guide-to-hiring-qualified-tile-installer

The only way to waterproof a window from the inside is to put a shower curtain in front of it. It doesn't matter at all about the wall or window sill tile being properly waterproofed, it is about the window "frame" and sashes.

I personally would not go with single pane glass on the off chance a glazed unit fails. If it fails, replace it.