In my previous post I have covered some of the basic topics regarding the KNX:

• What is the KNX?
• What are the areas of the home and building control which are covered by KNX?
• How does the KNX installation work?

But there is one more very basic, yet very important question which needs to be answered.

Why would someone use KNX in his house or building environment?

What are the positives, the incentives?

What are the negatives, the drawbacks?

What are the obstacles preventing someone to implement KNX installation and start using it?

For the easier reference in this post I will refer to the KNX installation inside of a residential house. The same arguments would apply for any other residential objects like building flats, condos, cottages …

The positives

So let’s start with the positives. Why would anybody want to use the KNX installation in his house? What are the benefits?

In my mind the main benefit is the convenience and the comfort for the house residents that comes with the KNX installation.

KNX installation takes a regular house and transforms it into a “Smart house”. And why is this important? Smart house provides various automatic functions which add value and quality to the life of its inhabitants.

Take lights for example. In a regular house there are a lot of light switches on the walls. If someone wants to turn on the light he or she has to walk up to the light switch and manually turn it on. But in a Smart house the need to turn the light on can be anticipated and acted upon. Maybe the light in the room is getting darker and light needs to be turned on, automatically. Maybe you walk into an empty room, and since it is dark in the room, the lights are turned on, automatically.

You may argue that this is an overkill. I mean seriously, how hard is it to turn the light switch on and have a light in the room.

Although this is a valid point, I can definitely underline some use cases when automatic lights are a great help. For example: you are walking into a house after your annual week grocery shopping. Your both hands are full with the things you have bought. I know I have this situation every week. Wouldn’t be great if you didn’t had to turn the light on with your forehead or your nose just to make it to the dining table without tripping over a chair or a toy that your child has left lying down on the floor?

There are other use cases where you simply cannot achieve desired level of comfort with the regular house. You like a certain amount of light in the room. As the sun is setting down the room is getting darker. The lights need to progressively turn on in order to maintain that perfect amount of light in the room. There is no argueing that you cannot achieve this with the regular house.

The other very important reason is the security. This is something that people always take very seriously. With the KNX installation you can create an event whenever the door or window is openned. For example SMS or e-mail is sent to you when such an event occurs. This gives you a great little overview that something is happening in the house. Yes, there are independent alarm systems that provide the same functionality, but this is an integrated house system which fits nicely with all the other systems.

Also there are other events that can be monitored and acted upon. For example you install the water sensor in the bathroom. One day there is a leakage because one of the pipes is broken. The water sensor will pick up the event and automatic reaction of the system can be executed. Main water valve is turned off preventing a major flood in the house. Automatic call to the maintenance company is executed with the information about the issue.

Another important benefit of the KNX installation is the energy efficiency. This is a very trendy topic and there are a lot of energy aware people. People who would love to live in the eco friendly house.

Besides feeling good there are economic benefits from owning and living in the energy efficient house. Benefits like tax reduction, maintenance costs reduction and many other which are provided by the state you are living in. And all you have to do in order to enjoy these benefits is to live in a house which has an energy efficient A rating.

Another example is house price. Houses with better energy rating have greater market price than houses with lower energy rating. This means that by installing the KNX into your house you are increasing value of the house you are living in.

One can say that you can have a passive energy efficient house.This is true to some degree. Using good building materials and renewable energy sources can help to increase house energy rating. But these passive systems can only get you halfway. When they are combined with the automatic management of a Smart house full energy potential can be realized. This is another area where KNX fills the gap perfectly.

The negatives

Of Course there are some downsides to the implementation of the KNX installation in the house.

The most important one is the price. KNX equipment does not come cheap. It can easily cost up to couple tenths of thousands of euros. And this is even without going crazy with the exotic control and use cases. Equipment very quickly adds up and with it the total price of the project.

Part of this investment will return over time. But it is still an investment and one that you have to do upfront, before you start using the house.

The other downside is that it is very difficult to install the KNX network into an existing house. KNX bus wires need to be laid down and electric wiring needs to be restructured. As you can imagine this is a major house project, not something that can be done easily.

In most case the KNX installations are created during the building of a house or during the major reconstruction project. This is a perfect opportunity to lay the foundations for the KNX installation. At this point it is not crucial to install all the KNX devices and controls. But it is crucial to identify the needs and prepare the wiring for it. There is a saying among KNX installeres that the wiring in the house is the most important thing. When you realize that that there is a KNX function missing and that there is no wire in place there is very little that you can do.

Final verdict

It is clear that the positives outweigh the negatives by some margin. Yes, there is a significant price tag which goes with the KNX installations. But the benefits are just too good. Comfort that KNX installations provide is enough on its own to justify the investment.

So, why use the KNX?

The great truth is that people are lazy.

People are absolutely addicted to effortless comfort.

If there is a system that can provide this, no price is too big.

KNX is that system.