- The glass has smashed from an impact such as a stone hitting it from a lawnmower
- You have been broken into and suspects used the window to gain entry
- The glass has blown (lost its airtightness) from constant water build-up around the seals, which is common in bathrooms
- Extreme weather or pressure changes have caused a crack
- Including the beading (the plastic and rubber seals around the windows that can be removed), measure the width of the window frame.
- Do the same for the height of the window, making sure you include the beading.
- Then, take 10mm off each measurement, and you have the approximate size of your glass.