How I built a fully offline smart home, and why you should too

As someone who grew up with a dial-up internet connection, I get anxious at the thought of any always-online product or service. My smart home is no different — I rely on it to automatically cool the room when I return home, light up my closet when I open the door, and match the color temperature of my lights to the sun’s position. Why should any of that require an internet connection? That train of thought is exactly what led me to build a fully offline smart home that doesn’t hinge on any third-party servers whatsoever. And here’s how you can do it, too.

Why build an offline smart home?

One of my biggest fears is that the manufacturer of a smart home product I use will go bankrupt and disappear overnight. It’s not an unfounded fear — just last year, smart home company Insteon abruptly announced that it would shut down its servers over financial difficulties. The servers would later return from the dead, but only because some loyal users acquired the entire company to keep its products alive. This isn’t a one-off example either — Philips stopped supporting its first-gen Hue Bridge in 2020 and MyQ’s garage door openers became incompatible with the Google Assistant without warning in 2023.

Many also care about the privacy implications of having cheaply made devices connect to the internet, but that’s a relatively smaller concern for me. Nevertheless, an offline smart home setup insulates me from both potential bankruptcy and privacy invasions.

If those two reasons aren’t enough, you can sometimes also save a few bucks going the offline route. Instead of paying a premium for smart coffee makers or washing machines, you can retrofit almost any existing appliance with smart plugs and switches. Those can often be controlled without an internet connection, making them much more reliable than manufacturer ecosystems.

In my smart home setup, I haven’t explicitly blocked all devices from connecting to their manufacturer’s servers. About half of them still remain accessible via their official apps, just in case. But in day-to-day use, they’re all controlled by an offline hub and every single automation runs locally. If I were to disconnect my internet connection, they’d still continue working normally till the heat death of the universe. Or until a few batteries inevitably run out.

How I built my offline smart home

If you’ve ever looked into building a locally-controlled smart home, you’ve probably come across Home Assistant. It’s a truly excellent piece of open-source software, maintained by enthusiasts from around the world. As a result, it’s not aligned with any smart home brand in particular and doesn’t need profitability or user growth to stay alive. Getting started with Home Assistant is dead simple; you simply install it on a low-power computer like the inexpensive Raspberry Pi. From that point on, you can configure your entire smart home using a smartphone or laptop.

Home Assistant uses code underneath its pretty UI for its automations, scenes, and other actions but you don’t need to worry about that at all. The graphical user interface has improved leaps and bounds in recent years and you can achieve just about anything without touching a single line of code. Here’s what one of my automations looks like:

The passionate Home Assistant community has also built blueprints that you can import for niche devices like the Aqara Magic Cube (pictured above). Typically, you’d need Aqara’s Hub and have to configure the cube’s actions via the official app. Thanks to Home Assistant, however, I don’t need another app or hub.

Hub aside, I use a mix of Wi-Fi and Zigbee devices throughout my home. Zigbee is the wireless mesh protocol behind many ecosystems like Philips Hue and IKEA Tradfri. With such ecosystems, however, you’ll often need to buy a brand-specific hub. Home Assistant once again lets you sidestep that requirement — simply plug in a single Zigbee USB dongle and build your own brand-agnostic network.

Some devices can be a bit problematic but there’s always a workaround. Take my robot vacuum, for example. I bought it over five years ago — long before I had any inkling of the broader smart home market. Luckily, the first-gen Xiaomi robot vacuum (and a few others) can be rooted and flashed to run Valetudo, a cloud replacement software. Do I recommend installing it on your device? Only if you can figure out the basics of a Linux filesystem and are comfortable with reading documentation. Don’t worry if not, I’ll recommend some alternative vacuums in the next section.

Home Assistant maintains over 2,500 integrations. This means support for nearly all major brands and platforms like Philips Hue, Nanoleaf, Sonos, Plex, and Google Nest. You can go even further with custom integrations since it’s an open platform.

All of this means that Home Assistant can create automations between brands even if they don’t play nicely with each other. I use an IKEA-branded wireless switch to dim my Xiaomi lights, turn on my LG air conditioner, and open the Plex app on my webOS TV. This may be possible with Alexa or Google Home routines, but the depth of device support in Home Assistant is staggering. Not to mention, every interaction is processed instantaneously since no packets leave my home network.

How to build your own offline smart home

While you can use many Wi-Fi-based smart home products offline, I’d recommend using Zigbee wherever possible. Such devices, whether a Philips Hue bulb or an IKEA remote, will directly connect to your hardware running Home Assistant. This also means faster communication and zero reliance on the brand for anything except optional firmware updates.

So with all of that in mind, here’s a list of the most common device categories and which brands I’d recommend for an offline smart home.

• Hub: Install Home Assistant on a Raspberry Pi 5 or 4 and plug in a Zigbee USB stick (optional). Alternatively, pick up the Home Assistant Green hub that’s pre-flashed and ready to go.
• Smart bulbs: For Wi-Fi, you can buy bulbs with offline firmware from Shelly and Athom. Xiaomi’s Yeelight sub-brand also offers official LAN control that you simply need to enable in the app. You have many more options with Zigbee. I prefer IKEA’s Tradfri line of Zigbee products as it strikes the perfect balance between quality and price, but you could also splurge on Philips Hue and myriad other brands.
• Switches and plugs: Inovelli’s Zigbee switches are a favorite in the Home Assistant community, but they aren’t cheap at $50 a pop. Zooz and Lutron come in a close second. You’ll find many more options for smart plugs, with offline-only options from Sonoff, IKEA, Athom, and Shelly.
• Sensors: Looking for the cheapest possible option? Sonoff’s range of sensors works reasonably well. However, I’d recommend Aqara or Aeotec products for better reliability, even though they need Zigbee and cost a bit more. I use IKEA’s motion sensors throughout my home and they work incredibly well too.
• Robot vacuum: Flashing the aforementioned Valetudo project isn’t for the faint of heart, but it’s the best option to keep your robot vacuum offline-only. You’ll have to check if your vacuum is on the list of supported models, though. Alternatively, Home Assistant officially supports Dreame and Roborock vacuums.
• Blinds: IKEA’s smart blinds are a favorite in the smart home community for their affordability and compatibility. I’ve also heard good things about Third Reality and Smartwings, which come equipped with Zigbee.
• Other appliances: Want to automate your AC, garage door, or ceiling fan that has its own remote? Use an inexpensive Wi-Fi IR or RF blaster. I saved $100 buying an AC without smart features, whereas my Broadlink RM Mini IR blaster cost just $20, and can also control my ceiling fan and TV in the same room.

This is not an exhaustive list, of course, and I’ve only recommended reputable brands that shouldn’t compromise your data if you do connect them to the internet. Having said that, I’ve taken the more adventurous route for my own smart home and picked up a few bottom-of-the-barrel products off AliExpress.

These unbranded Wi-Fi products often use the Tuya Smart IoT platform, which integrates into Home Assistant via official and third-party integrations. These devices phone home surprisingly often, though, so they’re universally regarded as a bit of a privacy nightmare. One solution is to use the local Tuya custom integration and block those devices from accessing the internet with a firewall on your router. As I said earlier, Home Assistant offers a workaround for just about anything if you’re dedicated enough.

Moving on, you don’t have to worry about losing voice control via Google Assistant, Siri, or Alexa. With some configuration, you can control all of your Home Assistant devices via your existing smart speakers and displays. I personally don’t need this functionality, though. I have wireless Zigbee switches placed all over my home to activate scenes and control lights.

What about Thread and Matter?

I’ve advocated for Zigbee so far, but you should know that another wireless mesh protocol is on the horizon: Thread. The good news is that you can add Thread support to your Home Assistant installation quite cheaply — it’s as easy as plugging in a USB dongle.

I’ve not made the switch because Thread and Matter are still quite barebones. We don’t have many Thread-compatible devices on the market to choose from either. That’s unlikely to change for a while as manufacturers work through some of Thread’s current challenges. For example, many Thread routers currently lack a way to add devices from other brands to their network. Without using something like Home Assistant then, this means you’re left with multiple different Thread networks that can’t talk to each other or share devices for automations.

Thread may replace Zigbee someday. But considering that Zigbee is a mature protocol with hundreds of devices available today, it remains my top choice and recommendation. I’m not alone either, this sentiment is echoed by many in the Home Assistant community.

Is an offline smart home worth it?

Building my offline smart home took the better part of a weekend and it did require some research to know which products worked best offline. The Home Assistant interface can also take some getting used to, but it’s quite beginner-friendly these days. Even if you don’t see it as a hobby, a small time investment is well worth the benefits of an offline smart home.

That said, my recommendation wholly depends on the intended user. I wouldn’t set up a Home Assistant installation at my parents’ home, for example. A battery may run out and I may have to re-pair a device or two every few months. In that vein, troubleshooting an offline smart home can be difficult when you don’t have physical access to the devices. For such homes, I’d still use a cloud-based solution like Google Home in conjunction with big-name brands that offer simplified setup processes.

Personally, though, I can’t imagine going back to the world of walled garden smart home ecosystems. And with any luck, I’ve hopefully convinced some of you to make the jump, too.