“Recently, we’ve been doing a lot more interior windows,” says Imogen Pritchard, director of American design for Plain English, a British custom cabinetry manufacturer that has a showroom in New York. Now that people are moving away from large, open-concept floor plans, Pritchard says, the benefit of adding glass to a room division is that it lets in light without making the space seem smaller.
“You end up with spaces that feel separate but connected,” she says. This can be especially useful in smaller homes or in apartments that have been hollowed out of larger, grander apartments from an earlier era, says architect Andrew McGee, co-founder of Format Architecture Office in New York.
Interior windows also create what Parisian interior designer Marianne Evennou calls “openings for the eye to escape”. They, along with the wall openings and glass doors that are characteristic of Evennou’s work, can make a small room feel less claustrophobic and add interest to a home.
Done well, an interior window also increases a home’s charm factor, says Pritchard, noting that Plain English designs interior glazing with wood-framed panes inspired by those used in historic homes. “I think the little panes help [an interior window] feel softer and a bit more like furniture,” she says. Evennou also loves window glass, but she opts for steel-framed designs for an industrial look.
Replacing solid walls with walls equipped with interior glazing is particularly useful for separating a kitchen from a main living space, a kind of compromise between an open kitchen or a closed kitchen. It’s also a traditional technique in the kitchens under the stairs of English country houses, where many cooks worked simultaneously, says Pritchard. She also likes to add windows to a pantry to keep it from feeling like “a black hole.” “Sometimes we even make glass shelves in front of the glass, so you can see through,” she adds.
And if concealing a messy space is a concern, Pritchard suggests using fluted or fluted glass, which lets light in but obscures what’s beyond — effectively borrowing light, but not view. McGee’s company used ribbed glass to bring light into a windowless entrance hall while providing privacy to the office/guest room combination on the other side. Ground glass also works well for this, he says.
Experts say it should be possible to put an interior window in most non-load-bearing walls. The project will consist of ordering a custom piece of glass and hiring a professional to install it. (Pros warn that it won’t look good if your contractor just glues an exterior window into a wall.) Whether you need to hire a designer or an architect will depend on the existing space and what you hope to create. Either we can look at your house and give you a rough idea of what is possible. They will, however, need to survey the walls to determine which pipes, cables and structural elements need to be considered.
If tearing down walls and ordering custom glass sounds daunting, there are other ways to borrow light: Swap an existing door for one with glass panels, for example. Or consider adding a transom window above a doorway, which the regular English architectural office and Format like to do when ceiling height allows.
While the extra light is a boon for small spaces, there are a few downsides. Depending on the type of glass and how it is installed, you may sacrifice some sound insulation. And Deeksha Gaur, a homeowner in New York, found that the airflow in her home (both for heating and cooling) was affected when she closed off the corner of her L-shaped living room with a wall. window.
Privacy was also a concern for Gaur. She uses the room as a home office and guest bedroom, so she added roller blinds to the windows. Small hiccups aside, Gaur loves her interior windows, and the addition was such a hit that her downstairs neighbor copied the idea. (In Gaur’s experience, they left a gap above the windows to help airflow.)
Opening up walls or building new ones to add an interior window is also expensive (i.e. thousands of dollars), but the pros and homeowners we spoke to say borrowing light is a profitable investment if you can swing it.
As for the term “borrow light”, McGee deliberately talks about “stealing” it instead. He says it’s because light is priceless and people should go to great lengths to maximize it. “Natural light in some apartments is so valuable that you may need to be prepared to take it a little harder,” he says.
Laura Fenton is a freelance writer in New York.
