Pros & Cons of Glass Block Windows

Pro: Energy Efficiency

• Properly installed, a glass block window can be virtually airtight. Traditional windows, be they den windows or basement windows, cannot be as well sealed as a glass block window simply because they have to be able to be opened. Glass block windows can keep the heat in in the winter, the cold in in the summer, and look good year round.

Cons: Light Transmission

• Glass block windows let in less light, and in some cases much less light, than traditional windowpanes. They are significantly thicker, and contain something of an air bubble in the center, which diffuses light and makes the material more opaque. Consequently, rooms with glass block windows may be darker than with a traditional window, and it is difficult to make out solid shapes or faces, so it may be a poor choice next to a front door where you would want to be able to see who is calling.

Pros: Security

• Glass blocks may appear fragile, but they are actually quite strong, having much thicker glass than a traditional windowpane. Glass blocks are fit securely in to their frame, and cemented in place. Properly installed and cemented, a glass block window is akin to a cinder block window; it would be extremely difficult to break in through glass blocks.

Cons: Ventilation

• Owing to their inability to open, glass block windows are not good choices for windows that will be used for ventilation. In a basement environment, this can be problematic, as hot water heaters and heating units that run on gas or oil need air to heat. In these situations, glass block windows can be installed with a small vent that allows air to pass through and keep things circulating.