After a full renovation, a homeowner made the lighting, blinds and heating smart with a handful of wireless devices and one app. A few years later the manufacturer stopped supporting the app, the cloud service shut down, and some of the devices became ordinary switches. When choosing a smart home platform, the main question is not what is most convenient today. It is what will still work in fifteen years, when the walls are long closed.
There are two main paths: a wired system, whose most widespread open standard is KNX, and wireless ecosystems — Zigbee, Z-Wave, Thread/Matter and Wi-Fi devices. This article looks at where each is strong, what hidden costs and risks they carry, and how to decide. The same principles apply to smart building projects, from a small office to a hotel.
Two different philosophies
KNX is an open international standard for building automation. Devices — switches, actuators, sensors, thermostats — are linked by a dedicated wired bus, usually run alongside the power cabling. Hundreds of manufacturers make compatible devices, and the system is decentralized: each device knows its own function and keeps working even if a central controller goes offline. It is programmed with a standard tool (ETS) used by any qualified integrator.
Wireless systems work over radio. Zigbee, Z-Wave and Thread form a mesh network in which devices relay signals to each other, and they usually need a central controller (hub). Wi-Fi devices connect directly to the home router and often depend on the manufacturer's cloud service. Matter aims to provide interoperability between ecosystems, though it is still evolving.
Where KNX wins
- New build or full renovation: the bus cable goes in at the same stage as the electrical installation, with minimal additional complexity.
- Reliability: a wired link does not depend on radio interference, wall thickness or batteries.
- Longevity: the standard has existed for decades and maintains backward compatibility; one manufacturer disappearing does not stop the system.
- Scale: the same technology works in an apartment, a house and a commercial building — for example, to control guest rooms in a hotel.
- Integration: lighting, blinds, heating and cooling, ventilation, energy metering and security systems in one logic.
Where wireless wins
A wireless solution has the advantage when opening walls is impossible or not worth it: an existing home that is not being renovated, a rented apartment, or adding individual functions step by step. The upfront cost is usually lower and installation is quick. If your goal is a few smart bulbs, some sensors and voice control, a wireless ecosystem is the logical choice and KNX would be overkill.
If you choose the wireless route, choose it carefully. Prefer devices that can be controlled locally, without the internet, and open standards — Zigbee, Z-Wave, Thread/Matter — over a closed ecosystem from a single manufacturer. Use one central controller rather than ten different apps. Place battery-powered devices where they are easy to reach. And remember: any wireless system is only as reliable as the home network it sits on.
Hidden costs and risks
The main drawbacks of KNX are the higher upfront cost and the need to plan ahead: the decision must be made before the plastering. In addition, programming needs a specialist, and if the project file stays only with the integrator, every change will depend on them.
The risks of wireless systems are less visible but accumulate over time: regularly replacing batteries in dozens of devices; mesh instability with thick walls or in a large house; congestion in the 2.4 GHz band, which Wi-Fi also uses; dependence on a cloud service — functions may be lost when the internet goes down or the service shuts; and security updates that the manufacturer stops releasing after a while.
For a fair comparison, look not just at the upfront price but at the total cost of ownership over the whole time you expect to live in the home: replacing devices when support ends, batteries, integrator visits for changes and — hardest to measure — the time you yourself will spend keeping the system working.
The hybrid approach: the best of both
In practice, the best solution is often a combination. KNX controls what lives in the walls and must last for decades: lighting, blinds, heating, ventilation. Wireless devices are added where flexibility matters: extra sensors, portable devices, voice assistants, new functions that will appear in future. A gateway or visualization server links the two worlds. That way, if the wireless ecosystem changes, the backbone of the home stays the same.
For example, in a new three-story house, KNX might control the lighting, blinds and underfloor heating in every room, while wireless sensors are added on windows and doors where running cable is awkward, and in the garden, where the irrigation system may change later. In such a scheme the core functions of the home do not depend on the internet, and the mobile app and voice control add comfort rather than being a necessity.
A decision checklist
- Are the walls being opened? For a new build or full renovation, seriously consider KNX — or at least pre-installing the bus cable.
- How long do you plan to live in or own the property? For long-term ownership, reliability and lifespan matter more than upfront price.
- Which functions are critical? Lighting and heating should keep working when the internet is down.
- How ready are you for ongoing upkeep — replacing batteries, updating apps, re-pairing devices?
- Who will service the system in five years, and will you receive every project file and password?
- How is the home network planned — Wi-Fi coverage, cabling for cameras and access points, space for equipment?
Tips for the planning stage
Even if you are not planning full automation today, preparing for the future during a renovation is very cheap — and expensive later. Run bus cable to every switch, thermostat and blind position; wire lighting circuits so that each can be controlled separately; leave space in the distribution board for actuators. And do not forget structured network cabling — a stable wired network is the foundation of any smart system in the home, including the wireless ones.
If you are planning home or building automation and want a decision that stays relevant for years, get in touch — we will help you weigh the options against your property and goals.