Energy-saving tips for tenants and landlords

The simplest and most effective way to save heating energy is to lower the room temperature. For every one degree Celsius reduction in temperature, around six percent of energy can be saved. Sometimes rooms are too overheated. A temperature of 20 to 22 degrees in the kitchen and living rooms is sufficient; 22 to 24 degrees in the bathroom, 16 to 18 degrees in the bedroom; 16 degrees in the cellar and 22 degrees in the children's room.

Many boilers or heating systems allow the temperature to be lowered overnight. However, to prevent mold infestation, the room temperature should not drop by more than three to four degrees overnight. This can be achieved by extending or shortening the switch-off times. Lowering the temperature at night is particularly useful in older buildings that are less well insulated or have poorer thermal insulation. Depending on the building and heating system, savings of five to ten percent are possible.

Most thermostats nowadays have a scale from one to five and can be controlled manually. One stands for around twelve degrees and five for around 28 degrees. The distance between two levels is therefore around four degrees. Important to know: The room will not warm up any faster if the thermostatic valve is turned up fully to five. Instead, there is a risk of forgetting to turn the thermostatic valve down again as soon as the sensible room temperature is reached. This wastes energy unnecessarily.

Not only is it mandatory under the German Building Energy Act (GEG) to insulate accessible pipes, it also makes economic and energy sense. Depending on the heating water temperature and average pipe length, energy losses can amount to up to 250 kilowatt hours per running meter. Good insulation can reduce these losses by 70 to 90 percent. Good insulation is approximately as thick as the diameter of the pipe.

To further reduce energy consumption, it can be helpful to carry out hydraulic balancing. This is usually carried out when changes are made to the fabric of the building or its energy efficiency. Hydraulic balancing should be carried out by an expert who will set the individual radiator correctly.

Every thermal bridge in the surface of a building represents a weak point. It is therefore important to reduce heat loss to the outside. Tilted windows are a weak point in the cold season. These cause the immediate walls around the windows to cool down more. In addition, the ventilation effect is very slow and it takes a long time for the entire air content of a room to be exchanged. Ultimately, heating up cold air consumes less energy than warming up cooled walls. So here's a tip: keep the air fresh with short bursts and cross ventilation.

To ensure that the heat flow can pass unhindered to the room air, it is sensible and necessary that the radiators are not obstructed by furniture or curtains. A minimum distance of 30 centimeters should be maintained between radiators and furniture. Curtains should also end above the radiators and not reach the floor. All this prevents heat from building up and being released into the room.

In buildings from the 60s and 70s, heating niches are predominantly found. Due to their design, these have a thinner wall thickness and therefore lower thermal resistance. This means that a comparatively large amount of energy is lost through this area. However, retrofitting insulation with insulating mats is also possible. You can fit these yourself.

In most households, domestic hot water and heating water are supplied by the same boiler. This means that the consumption of heated domestic hot water has a direct influence on the total heat consumption of the house. Taking a bath with 150 liters of water requires around four to five kilowatts or 0.4 to 0.5 cubic meters of natural gas. Only around a third for showers. But here too, even more energy can be saved by using water-saving heads and shorter shower times.

Energy consumption can be reduced with an instantaneous water heater, whether electric or gas. If the hot water flow rate is sufficiently high, it is sufficient to set the temperature of the instantaneous water heater to 55 degrees. With a previously set temperature of 60 degrees, around ten percent energy can be saved.

If you want to buy a new household appliance, such as an oven, fridge, freezer, washing machine or vacuum cleaner, you should make sure that the appliance does not consume energy unnecessarily. We recommend buying appliances in energy class A+++.

A good overview can be found here:

Proper ventilation is necessary to prevent mold in homes. However, heat energy is lost during ventilation. Ventilation systems help to capture this energy and supply fresh air. At the same time, they remove moisture from the room air and supply fresh outside air. In new buildings, ventilation systems are a necessary component in order to meet energy saving requirements. However, they can also be retrofitted in existing buildings.

Further information:

In an average household, lighting accounts for around nine percent of electricity costs. With older lighting elements, a large proportion of the energy used is converted into heat and only a small proportion into light. Earlier light bulbs, for example, converted around 95 percent of energy into heat and only around 5 percent into light. With modern LED light sources this is exactly the opposite. Here, 90 percent or more of the energy is converted into light.

The sun sends as much energy to the earth in one hour as the world consumes in a year. By using photovoltaic elements, the energy of the sun's rays can be converted into electricity. On average, around 1,000 kilowatts per kilowatt hour of peak output per year can be achieved. Whether the roof is suitable and how high the yield can be can be viewed on the LUBW website.

In addition to electricity, heat can also be generated from solar energy. Solar thermal energy offers a sensible and financially advantageous alternative for heating support and hot water heating, particularly in new buildings. However, the use of solar thermal energy to heat hot water can also make sense in existing buildings. BAFA promotes the installation of solar collectors. The Federal Office of Economics and Export Control provides an overview of the funding programs.

Especially on hot summer days, people like to switch on the air conditioning. However, air conditioning systems require more energy and lead to higher electricity costs. If you still don't want to do without air conditioning, you should opt for the highest efficiency class A+. It is easier and cheaper to ventilate at night or in the morning. Rooms should also be darkened throughout the day. Blinds, shutters, curtains or even shutters with narrow light slits are suitable so that you are not sitting in the dark.