About 90 percent of domestic energy consumption in Germany goes on heating and water. Space heating accounts for the major share by far – i.e. around three-quarters of domestic energy consumption, with much of this being lost through walls, windows, the roof, doors or floors. Old boilers and oversized, incorrectly set and inefficient circulating pumps also send electricity and heat consumption soaring.

Existing buildings need better insulation and inefficient heating systems must be replaced by modern facilities. Mini block-type thermal power units are particularly efficient. Innovative concepts are needed for new buildings. After all, who wants to heat the outdoors instead of the living room? In existing buildings, energy demand can even be reduced by as much as 90 percent but with an average reduction potential of at least 50 percent.

Questions and Answers: Energy Efficiency Tips for Buildings and Heating

Electricity, gas and oil are more expensive than ever, so intelligent energy management has never been as worthwhile as it is today. But what does energy efficiency actually mean? What are the benefits – for the environment and our own pockets? Must we accept drastic limitations in order to consume less energy? And what is the German Government doing to boost energy efficiency and reduce energy consumption? The Federal Environment Ministry answers some frequently asked questions.

How can I save heating costs at home?

Through intelligent heating and correct ventilation: intelligent heating alone can reduce energy consumption by as much as 10 percent. Turning your thermostat down by 1ºC cuts energy costs by 6 percent. Don't cover radiators or block them with furniture, and don't allow curtains or washing to drape over them, in order to allow the heat to circulate freely – this can account for up to 20 percent of heat consumption. Correct ventilation also saves energy: it is much more energy-efficient to open all the windows for a short time than to keep them slightly ajar all day. Fitting a central heating control on the boiler saves energy too, e.g. by automatically reducing heating temperature at night. Last but not least, correct flow balancing through hydraulic compensation as well as regular servicing will keep your heating system running efficiently.

How can owners improve their properties' energy efficiency?

There are two main methods: better insulation, and more efficient technology. Firstly, heat loss through the shell of the building can be reduced by insulating the exterior walls, installing double glazing, insulating the roof and the ceiling of the basement, and lagging heating and hot water pipes in unheated rooms. Secondly, substantial savings can be made through the use of efficient technologies; for example, condensing boilers should be installed instead of standard or low-temperature boilers and combined wherever possible with renewable energy systems such as solar panels. A modern condensing boiler alone can reduce energy consumption by as much as 30 percent compared with a standard boiler.

For maximum energy performance, a heating system must also be operated efficiently, however. Hydraulic compensation should be conducted between the various sections of the heating system in order to ensure that heat is distributed evenly throughout the building; this can be achieved through the use of adjustable thermostat valves. Signs that hydraulic compensation may be required include "knocking" noises in the system and radiators failing to heat properly. It may also be necessary to "bleed" radiators which are not heating properly or evenly. Noise may also result if circulating pumps are set too high. Many pumps are oversized and run constantly – and unnecessarily – in summer as well as in winter. Homeowners who install modern pump technology recoup their investment in less than two years on average due to the electricity costs saved. Frequently asked questions about the energy consumption of circulating pumps are answered at "Pump Check", a free website at (in German).

How can I carry out an energy efficiency health check?

Advisory and support services are a good place to start. For example, the Federal Environment Ministry offers a free interactive service on its climate protection campaign web pages, with advice on upgrades and improvements that can boost energy efficiency at home ( (in German)). And through its "Energy-Saving at Home" programme, the Federal Ministry of Economics and Technology (BMWi) is subsidising the provision of professional individual energy advice for homeowners ( Tenants can also find out about their residential building's energy consumption. Many local authorities carry out municipal heating surveys which collate and present data on buildings' heating energy and heating costs, thus creating a basis for sound and objective comparisons ( (in German)). The German Government also plans to introduce energy certificates for the building stock, in order to provide information on buildings' energy performance, such as the level and quality of thermal insulation. Energy requirement certificates have already been introduced for new builds and full renovations in accordance with the Energy Saving Regulation of February 2002.

What is the German Government doing to boost energy efficiency?

The German Government has substantially increased the CO2 Building Rehabilitation Programme from the previous level of €360 million to €1.4 billion annually – quadrupling the programme's previous budgets. This taps into an important energy source, as space heating accounts for three-quarters of domestic energy consumption and is often energy-inefficient. By March 2006, around 342,000 energy upgrades for homes had received support under the programme, which is also stimulating the labour market: every €1 billion invested in the building stock safeguards or creates around 25,000 jobs. Low- interest loans for CO2 building rehabilitation are available from the government-owned development loan corporation KfW (


There are many – often very cheap and simple – ways of improving energy efficiency and saving energy, thereby greatly easing the burden on the environment and our own pockets. Energy saving has never been more worthwhile. And although purchasing new higher-efficiency appliances or installing better thermal insulation does involve a more substantial investment, it pays off in the longer term.