How to Bring Natural Light into a Dark Room Without Removing a Wall
You can bring natural light into a dark room without removing a wall by letting daylight pass through a partition instead. Designers call this borrowed light: light travels from a bright room into a darker one, while the two remain separate spaces. The idea is old. The Shakers used interior windows to carry light from room to room through long, dark winters.
For years, the answer to a dark apartment was simple: take down the walls. Open kitchens and open living spaces became the ideal, and then many of us discovered that we miss something. Not a closed box, exactly, but the feeling that the entrance is an entrance, and that the desk isn't sitting in the middle of the living room. Here are four ways to pass light through a wall while keeping the separation, and a fifth for when you can't open the wall at all.
By Maya Sheinberger | 28.10.26
Key takeaways
Borrowed light passes daylight through an interior wall, so you keep the room.
Clear glass gives the most light and the least privacy. Reeded glass and glass blocks balance the two.
Glass blocks work best in measured doses, such as a strip or a section of wall.
Have an engineer check any wall before you open it.
Five ways to brighten a dark room with natural light, compared
Option | Light | Privacy | Best for |
Steel and clear glass partition | Highest | Low | Home offices, studies, dining areas |
Glass blocks | 40-80% in one maker's range | Medium to high | Entrances, corridors, bathrooms |
Reeded or fluted glass | Diffused | Graded by pattern | Small apartments, kitchens, interior doors |
Transoms and high interior windows | Depends on size | High, above eye level | Corridors, bathrooms, closed rooms |
Glass cabinet fronts | Reflected only | Doesn't apply | Narrow spaces with no possible opening |
1. A steel and glass partition
A steel and glass partition gives you the most light and keeps a clear line between two spaces. In my BN apartment project in Kiryat Ono, a 165 m² home, the old kitchen became a home office. A glass partition now separates that office from the dining area. It is 294 cm wide and 275 cm high, divided into three bays and three rows in a black steel frame, with 8 mm clear tempered glass and a door in one of the bays. The father of the family works from home, and the partition lets him keep eye contact with everyone while he works. The light passes through, and so does the sense of being together.
Remember that clear glass hides nothing, so it suits a space you are happy to keep tidy. It also won't give you much visual privacy unless you plan for that.
2. Glass blocks
Glass blocks let light through while blurring what's behind them, which is exactly what a bathroom or an entrance needs. They spent decades as a symbol of tired bathrooms and old office buildings, and now they are back. Hermès in Amsterdam occupies MVRDV's Crystal Houses, with a façade of specially engineered glass bricks, and Bottega Veneta's Milan store in the Galleria Vittorio Emanuele II sets square glass blocks into its walls and ceiling.
Not every block passes the same amount of light, so check the data sheet before you choose. The Seves Light Control range spans 40-80%, and its Light Diffusing block is rated at 63% light transmission.
The mistake last time around was quantity. Use them as a measured element: a vertical strip between a dark entrance and the living room, a section of a corridor wall, or a partial screen for a shower. Today's versions are far cleaner than the wavy blocks we remember. The more dramatic the block, the less of it you need.
3. Reeded or fluted glass
Reeded glass gives you soft, diffused light with more privacy than clear glass and a quieter look than glass blocks. In the DI duplex in Tel Aviv, I used reeded glass in the doors of the girls' bedrooms on the children's floor. It's the solution when you want to stay with glass and still keep privacy. It also suits cabinet fronts and partial partitions, and it is especially useful in a small urban apartment, where every bit of daylight counts. Patterns differ too: Pilkington grades its textured glass from 1, the least obscuring, to 5, the most, so choose by the privacy you need.
4. Transoms and high interior windows
A transom is a window above a door, and it borrows light without using up wall space. Architect magazine describes glass above eye level as a way to pass light to the next room while keeping privacy in both. This suits a corridor or a bathroom, where you need the wall below for furniture or fittings.
5. Glass in the joinery
When you can't open a wall at all, reflective cabinet fronts can make a narrow space feel brighter. In the N apartment in Tel Aviv, clear gray glass fronts on the cabinets beside the entrance workspace bounce light back into the space. It isn't a partition, yet it changes how the entrance feels.
How to choose the right way to bring in natural light
Start with the need rather than the material. Ask three questions:
What should pass through? Light only, or also a view?
How much privacy do you need? A bathroom and a home office have very different answers.
Is the wall structural? That one is a question for an engineer, before anything else happens. If you aren't sure who should lead the project, read Interior Designer or Architect: Which One Do You Really Need?
Then look at the rest of the room. These elements work when they solve a real planning problem. If your only reason is that the algorithm showed you the same kitchen forty times this week, sleep on it. And before you order the glass, read the six questions I ask in every showroom.
When daylight can't reach the room
If no daylight can reach the room, plan the artificial light as seriously as a window. The kitchen in the TA apartment in Tel Aviv has no window, so we designed a strong L-shaped recessed light with recessed spots above the peninsula to compensate. In my projects I use 3000K lighting with a CRI above 90 throughout the home, so the color of a windowless room stays consistent with the rest of the apartment.
Frequently asked questions
What is borrowed light in interior design?
Borrowed light means bringing daylight into a darker space through an opening or glass element in an interior wall, so that the room gets light from its neighbor.
Are glass blocks back in style?
Yes. Fashion brands including Hermès and Bottega Veneta have used them in their stores, and homes now use them in smaller, more precise doses than in the 1980s.
How much light do glass blocks let through?
It depends on the pattern. Seves rates one of its diffusing blocks at 63% light transmission, and patterns designed for privacy usually pass less. Check the manufacturer's data sheet for the block you choose.
How do I add light to a room with no windows?
Look at the wall it shares with the brightest neighboring room. A glass partition, glass blocks or a reeded glass door can pass daylight through that wall. Check with an engineer before you change any wall. If that isn't possible, plan strong recessed lighting at 3000K with a high CRI.
What glass thickness do you use for an interior partition?
For the BN partition, which is 294 cm wide and 275 cm high, I used 8 mm clear tempered glass in a black steel frame. Check the thickness with your supplier for the size of your panels.
Is a glass partition private enough for a home office?
Clear glass gives you separation, not privacy. If you need privacy, consider reeded glass or glass blocks, or use a mix of clear and solid sections.
Have a dark corner in your Tel Aviv home that's been bothering you for years, whether you live here or are managing it from abroad? Let's talk about it.
Maya Sheinberger is an interior designer with nearly 20 years of experience. She has run her independent studio since 2012, and it is based in Ramat Gan. She holds a B.Des with honors from the College of Management. Eight of her projects have won Archilovers Best Project awards, her work has appeared in more than 100 publications, and one of her Tel Aviv apartments features in the book The New Minimalist Style.
Photography @itaybenitphotographer · Styling @maya_livnat_harush
This post was inspired by my column on Mako (in Hebrew).
