fake window colors

The sun sets depressingly early during certain times of the year, and this can have a big effect on your mood. What if you could control when the sun rises and sets with a fake natural light window? We’ll show you how to tackle this DIY project.

Why a DIY Natural Light Window?

If you live in a location where there are extended periods of darkness, you know how important natural light can be. Seasonal affective disorder (SAD) is very common during these times of the year, and lack of sunlight is part of the cause.

There are plenty of products designed to help with this problem. However, if you want window-sized light, you’ll probably have to spend several hundred dollars. We wanted to add some extra light to our dim basement office and decided to go the DIY route.

We’ll show you how to make a faux window with natural light that changes to match the sun, all for less than $100.

light changing

What You’ll Need

Before we go any further, just a heads up that we’ll be using SmartThings for this project. There are a lot of smart home systems out there, so it’s hard to write a guide that’ll work for everyone.

If you want to get started with SmartThings, the first step is to buy a Hub, to which all your subsequent smart devices will connect. SmartThings supports many popular smart home brands. Once connected to the Hub, devices can be controlled through the SmartThings app.

If you don’t have a smart home setup, you can get similar results with a cheap “dumb” strip light. The only thing you’ll miss is the dynamic color-temperature shifting.

We’ll be using ZigBee Sylvania Smart LED Strip Lights. They’re full red, green, blue, and white (RGBW) lights and the color temperature can go from 2,700K to 6,500K. If those aren’t in stock, you can try this similar set from Sengled.

Next, you’ll need a fake window. If you’re DIY-inclined, you can build one for pretty cheap (it only cost us around $30). It’s essentially just a box with a light diffuser.

wood box
A simple wooden box.

We used a single 1 x 4, some 1/4-inch plywood, and an acrylic light panel. We made a small channel for the light panel to slide into, and you can either nail the plywood back onto it or inset it. We also recommend painting the inside white for maximum light reflection.

Alternatively, you can buy a shadow box that fits the length of your light strip. Our lights are 72-inches long, so the 18- x 18-inch or 12- x 24-inch shadow box would be perfect. You can tape some printer or parchment paper to the glass or acrylic to create a light diffuser.

shadow box
A simple shadow box like this works, too.

There’s one bit of DIY you’ll have to do regardless of how you get your window, and that’s drilling a small hole in one corner so you can feed the power cord into the box.

Finally, we’ll also show you how to set up a circadian rhythm automation with SmartThings. This will make the light change color temperature throughout the day just like the sun. You can even set your own sunrise and sunset times.

Assembling the Fake Window

We’ll begin by assembling the window. Basically, you just have to attach the light strip to the inside of the box. First, figure out where the end of the cord will be, and then drill a small hole for the power cord.

drill a hole for the power cord

Next, remove the paper from the adhesive backing and stick the light strip around the inside of the frame. Start with the end that will connect to the power source and make sure it’s aligned with the hole.

attach the lights inside the box

If you bought a shadow box, use some clear tape to attach white printer, parchment, or wax paper to the glass or acrylic. This will diffuse the light and make it appear brighter and more even.

That’s really all there is to the physical assembly. You can stop here if you want and still have a perfectly serviceable fake window.

However, if you want the color temperature to more closely mimic the sun, there’s one more step.

Set Up the Circadian Daylight SmartApp

SmartThings has a large library of community SmartApps that can do some really cool things. We’ll be using one called “Circadian Daylight,” which automatically adjusts the color temperature of your lights to match the sun in any given location.

If you’ve never used a SmartApp with SmartThings before, the process might seem daunting at first, but it’s actually pretty easy. We’ll walk you through it.

The process begins in the SmartThings IDE, which is the developer back end. Just go to https://account.smartthings.com/ in your web browser and sign in.

go to the smarthings IDE and sign in

Next, click “My SmartApps” at the top.

select My smartapps

Click “New SmartApp.”

new smartapp button

On the New SmartApp page, click “From Code.”

From Code tab

To install the first part of the SmartApp, copy the code on this page, paste it in the text box under the “From Code” tab, and then click “Create.”

paste code and tap Create

Click “Save” after the SmartApp is created.

click Save

Click “Publish” and select “For Me.”

Publish for me

Go back to “My SmartApps” and click “New SmartApp” again.

new smartapp button

Switch to “From Code.”

From Code tab

Now, we’ll install the second part of the SmartApp. Copy all the code from this page, paste it in the text box, and then click “Create.”

paste code and tap Create

Click “Save” after the SmartApp is created, but this one doesn’t need to be published.

click Save

You’ll then see two Circadian Daylight SmartApps on your account.

the two circadian smartapps

You’re now done with the SmartThings IDE. To complete the process, open the SmartThings app on your iPhone, iPad, or Android device.

open the smartthings app

Tap the hamburger menu on the right, and then tap “SmartApps.”

open the menu and select smartapps

Tap the plus sign (+).

tap the + icon

Scroll down to the “Custom” section and tap “Circadian Daylight Coordinator.”

select circadian daylight coordinator

Tap “Next” to set it up.

tap next to begin set up

The first thing you have to do is choose the minimum and maximum color temperatures. For reference, sunrise and sunset are around 2,700K, while at noon, it’s around 6,000K. Check your light strip specifications to see how close you can get to these numbers. When you’re done, tap “Next.”

enter color temperature values

Now, you can decide if you want the lights to match the sun in your location, or if you want to set their sunrise and sunset times manually.

For the former, type your zip code, and then choose an offset for the sunrise and sunset times.

enter your location

To set sunrise and sunset times manually, scroll down and select a time for each. This is particularly nice for those times of year when the sun sets early. When you’re finished, tap “Next.”

enter sunrise and sunset times

If you want to receive notifications when there’s an update for the SmartApp, toggle-On the “Update Notifications” option, and then tap “Done.”

tap done to save set up

You’ve now configured how the SmartApp will work. The next step is to tell it which lights to control. Tap “Circadian Daylight Coordinator” in the “SmartApps” section.

tap circadian daylight coordinator

Select “New Circadian Daylight Setup.”

new circadian daylight setup

Tap the type of lights you’re using in your fake window.

select a light type

Next, select the radio button next to the specific light you want to use, and then tap “Done.”

choose the light to use

Tap “Next” to proceed.

tap next

You can toggle-On the “Dynamic Brightness” option if you want the light to dim to match natural light. Type values for the minimum and maximum brightness, and then tap “Next.”

enable dynamic brightness and enter values

You can now decide if you want to set any “Sleep Settings.” If you do, just select the mode(s) for which it should run, how warm or cool the color temperature should be, and then select a brightness level. Tap “Next” when you’re done.

sleep settings

Finally, select the mode in which you want the SmartApp to be active, or you can disable it when certain switches are on. Click “Next” to complete the setup.

select modes and switches to disable the smartapp

Type a name for your window light, and then tap “Done.”

name the child smartapp

To save what you just did, you’ll have to go through the “Circadian Daylight Coordinator” settings one more time; just tap “Next” to skip through them all.

skip through the set up once more

You’ll return to the “SmartApps” screen when finished. Keep in mind the light will change every 15 minutes, beginning at the top of the hour, so you might not notice it changing immediately.


Your DIY version might not look as fancy as some of the expensive, premade faux windows, but this is a great alternative for the price. It also offers a lot more flexibility because you can make your window as big or small as you want.

Even if you don’t have SmartThings, hopefully, this guide has inspired you to try something similar with whatever setup you’re using and add some extra light to your space.

Joe Fedewa Joe Fedewa
Joe Fedewa is a Staff Writer at How-To Geek. He has close to a decade of experience covering consumer technology and previously worked as a News Editor at XDA Developers. Joe loves all things technology and is also an avid DIYer at heart. He has written thousands of articles, hundreds of tutorials, and dozens of reviews.
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