Does that self-cleaning glass actually work or is it just marketing?

Self-cleaning glass actually does work, but it's important to understand what it can and can't do — because "self-cleaning" is a bit of an overstatement.

How it works is through a dual-action process. The glass has a thin titanium dioxide coating on the exterior surface that does two things: it's photocatalytic, meaning UV light from the sun breaks down organic dirt and grime at a molecular level, and it's hydrophilic, meaning water sheets off the glass in a thin film rather than beading up, carrying loosened dirt with it as it runs down.

The result is that rain essentially rinses the glass clean rather than leaving water spots and streaks. In Ottawa's climate, this can genuinely reduce how often you're out there with a squeegee and a bucket.

Where it falls short is with inorganic debris — things like bird droppings, construction dust, pollen, and hard water mineral deposits. The photocatalytic reaction only breaks down organic material, so anything inorganic still needs manual cleaning. You'll also need consistent sunlight and rain for the system to work as intended, which means north-facing windows or heavily shaded windows get less benefit.

In Ottawa's context, the technology is most effective on south and west-facing windows that get good sun exposure. During our long winters with heavy snow and overcast skies, the photocatalytic action slows down significantly. That said, spring and summer performance can be genuinely impressive.

Is it worth the premium? Self-cleaning glass typically adds $50–$150 per window over standard glass. For hard-to-reach windows — second-floor or high transom windows — it can absolutely pay for itself in reduced cleaning hassle and safety. For easy-to-reach main floor windows, the value proposition is weaker.

It's a legitimate technology, not pure marketing — just go in with realistic expectations. If you're replacing windows and considering the upgrade, it's worth discussing which specific windows would benefit most. An installer can tell you whether it's worth it on your particular project — request a free quote through Ottawa Window Pros.