A last important item where integrated home systems will make a contribution is in rational energy consumption. We all know about the Kyoto standards, ozone depletion, global warming, and expensive fuel prices, and in the future we will have to consume less energy. An open window with the heating on is a no-no. The children are at school, but the children’s bedrooms are still heated... no need for that. Lights left on in the cellar and the attic... that can be avoided.
The greatest energy consumption in a home is still the heating (and/or air conditioning). Calculations by the VEI (Vlaams Elektro Innovatiecentrum [Flemish Electrical Innovation Centre]) indicate that in Flanders up to 15% of energy can be saved by cleverly linking the integrated home system to the heating system. We assume that the relative quantity of energy saved in the colder European countries will be higher than in the more southern environments. Regions around the Mediterranean Sea will perhaps make greater savings in the use of air conditioning. Savings can also be made with other energy clients (mainly lighting) but to a lesser extent.
In certain European countries, the total power of the home electricity supply is rather limited. The main switch will trip when too much equipment is being used at the same time. Integrated home systems can play a clever role here by temporarily switching off certain units when an overload is imminent, and with the desires of the residents taken into account.

Reducing energy consumption by reducing the power of the connection. Integrated home systems can play a clever role here. (Illustration source: Bticino)
Equipment that has a standby function with accompanying LED unnecessarily consumes energy (standby power) when not in use. In an ordinary home with a TV, DVD player, two computers with accompanying screens, a printer, an audio system, etc., the savings by switching off this equipment when not in use (out, sleeping, etc.) can be EUR 100 to EUR 200 per year.
The kitchen boiler under the kitchen sink (10 to 15 litres) is rarely switched off in normal circumstances. Nevertheless, at nights or when we are out, we do not need hot water in the kitchen. When at home (and not sleeping) or in the kitchen, the kitchen boiler can be automatically connected to the mains. In a short space of time we will have hot water again.
If we want to do one or more of the above things, we have to be aware of the consumption of the integrated home system itself. It differs somewhat from system to system. Certainly when managing the standby power, the additional consumption of the integrated home system must not be greater than the standby energy saved.
Increasingly, homes will have their own energy generating units. For example solar panels and micro CHP generators.