New glass costs anywhere from $3 to $100 per square foot. More specifically, tempered and insulated glass—a common option for sliding glass doors—costs between $10 and $14 per square foot.

Glass block installation can be relatively expensive due to the range of material costs and the labor time to assemble this type of specialty window. The process proceeds slowly as the glass does not absorb moisture from mortar and silicone caulk takes longer to harden, leaving spacers to hold up the structure until the caulk or mortar begins to cure. Plus, if your current windows have structural issues or damage, you’ll need to repair them before beginning the project, increasing your bottom line. 

Their thickness depends on application, but most glass walls are typically 3/8 to 3/4 of an inch thick. Although it’s not as common, single panes of glass can also be 1 inch thick.

Although glass block windows are made of multiple layers of thick glass, they can still break. If an individual block shatters, it can be removed and replaced, but this is a job for a window repair professional. The project is often complex and may require breaking the block further for removal. Do not attempt to handle it yourself, as the broken glass can be dangerously sharp. A professional will have the necessary tools and expertise to replace the broken glass block quickly and safely. Before hiring, confirm that the repair pro has experience with this specific type of window.