300 B.C.:

The Chinese install flue gas channels in floors and walls.

100 B.C.:

The Romans were using thermal heating.

1769 Germany:

Hot air heating in the new Palace in Potsdam (Sanssouci).

1770 England: 

James Watt used steam in order to heat his factory and his living areas.

1818 England:

Heating of buildings from a distance of approx. 270 m.

1876 USA:

Construction of world-wide first city heating in New York.

1878 Sweden:

The first city heating system was developed for hospitals. One hospital heating is already in operation.

1885 USA:

First Power Station with a heating centre (with direct steam).

1893 Germany:

The Power Plant in Hamburg was carrying out a test supplying steam at a distance of 300 m for heating purposes into the town hall; for the first time electricity and heat was produced at the same time.

1900 Germany:

Construction of the first European district heating plant in Dresden (steam power plant).

1911-1919 England:

First district heating for business premises in Manchester was constructed.

about 1920 Germany: 

Channel constructions of steam district heating in Berlin, Braunschweig, Frankfurt, and Hamburg.

1925-1936 world-wide:

In Denmark, Iceland, Canada, Switzerland, and the Soviet Union the construction of district heating is advanced.

after 1945 Germany:  

Because of shortage of fuel the construction of district heating is promoted.

1955-1973 world-wide:

200 stand-alone district heating systems were developed just in Denmark. Increasing importance of district heating in China, Finland, Great Britain, Iceland, Sweden and the Soviet Union.

1980 Germany: 

The Hannover district heating research Institute (Fernwärme-ForschungsInstitutes in Hannover e.V.) is founded by the Lower Saxony Government.

1990 Germany:

A very extensive programme (600 Mio. Euro) of reconstruction of the district heating systems in East Germany is implemented.

1997/1998 Germany:

"Liberalisation" and new federal government laws in respect to the power economy.

2000 Germany:

Law for the protection of the generation of current from combined heat and power.

Germany today:

The net of district heating is about 50.000 km long.

world-wide today: 

District heating is of great importance especially in the Scandinavian countries.