The Radiant 14th-Century Feature Every Home Should Have (It’s So Light-Filled!)

Last month my dad came down to the city to pay me a visit. We had a lovely day hanging out at home, and as we hugged goodbye I noticed something I hadn’t ever paid attention to on the front door to my apartment building. There were spherical shapes in some of the glass panes on the door, and I had no clue what they were or why they were there.

I asked my dad if he knew what they were, but he didn’t. My interest was piqued, so I went down a rabbit hole extensively researching these glass shapes — which I now know to be “crown glass” — in hopes to learn more about my building, and I’ve fallen increasingly in love with them. Here’s what some experts in real estate, home exteriors, and interior design taught me about crown glass on my journey to understand the architecture of my building.

Crown glass is a form of decorative glass that consists of a spherical disk of glass inserted into the middle of a regular glass pane through a process that can only be achieved by hand. This makes every piece of crown glass unique, and many are slightly imperfect instead of uniform.

Real estate expert Fred Loguidice, founder of Sell My House Fast, explains a bit about the process of making these distinctive glass panes. “To create panes of crown glass, a skilled glassblower would inflate a large bubble of glass and then attach it to a rod (a ‘pontil’). The bubble was then hand-spun rapidly until centrifugal force flattened it into a large, round disk. After cooling the disk, the pontil was discarded, and a characteristic, bull’s-eye mark was left in the center. The disks were then subsequently placed into individual panes.”

Due to being handmade, some of these disks would turn out thicker than others, or feature more ripples in the glass. But regardless of the final outcome, the process of purchasing crown glass proved difficult back in history, as its handmade charm and high quality made it expensive.

Crown glass was first developed in Europe back in the 14th century, but it didn’t burst into prominence until the 17th and 18th century in England and France. People adored its visual appearance, but because it was such a labor-intensive glass-making method, it was expensive, thus becoming a status symbol of wealth on the exterior of a home.

Depending on the household’s wealth, window panes featured more crowns of glass. As Cory Pinter, a real estate expert at Inherited House Guide, explains: “Individual glass crowns were too small to cover an entire window, so they were grouped using leaded metal cames (frames, or sometimes “glazing bars” or “astragals”) to form patterns. The more exclusive glass was in the product, the more costly.”

As beautiful as the panels were, their reign of popularity didn’t last long with the public in the grand scheme of things, mostly dying out around the 19th century. 

Aside from the houses of wealthy people, crown glass was often found on important buildings in a town belonging to the government or places of worship. Even still, since crown glass was so costly, most buildings only had one window displaying the sought-after design feature, usually in their most important, formal room for aesthetic purposes. The display helped to indicate the building’s grandeur and provide a slight boost in insulation where the disk in the glass thickened the panes.

“The pane size of the crown glass often reflected wealth as well as the building’s importance. The larger, smoother panes were a status symbol, while smaller panes were more common and practical,” says Elana Mendelson, a principal designer at Elana Designs.

This is another reason why crown glass wasn’t commonplace aside from cost: If it featured on every window, it would be harder to see through. The disks aren’t opaque, but they create a slight distorted effect, which is beautiful for warping beams of light onto the walls, but not so functional for seeing. This effect looked stunning in churches and fancy buildings, where seeing out of every single window with total clarity wasn’t a necessity.

While crown glass isn’t common today, it hasn’t gone extinct. It can still be seen on older historic buildings, or on buildings being renovated to preserve their original history.

As Dan Staupe, co-owner of Compass Exteriors, describes: “Nowadays crown glass is aesthetic. It’s still used in historical homes and in buildings where the decorative elements are especially special and valuable, but it isn’t as sought after today, likely because it’s harder to make and doesn’t represent a status symbol.”

In the historic city where I live, some restaurants and hotels feature small amounts of crown glass. But the majority of newer builds have reverted to mainstream window panes.

I’m sad to see that crown glass’s hold on the world has truly ended, but it makes it all the more special to come across while going on a walk. Perhaps if you keep your eyes open, you’ll be able to spot some, too!