Following the adoption of the European Union climate and energy package in 2008, the European Commission launched the Covenant of Mayors to support the efforts deployed by local authorities in the implementation of sustainable energy policies. The rationale behind is that cities have a crucial role to play in mitigating climate change, as they consume 80% of the energy produced in the EU. Further local authorities are in a position to influence local industries and citizens' behaviours.

The CoM initiative has been highly acknowledged by local and regional authorities and is a growing cooperation movement.  During October 2011 the Covenant of Mayors has reached more than 3,000 signatories representing 137 million citizens, and just over two years after the first Covenant of Mayors Ceremony.

The number of local authorities which have joined the Covenant – among which over 800 are already implementing their sustainable energy action plans – is conferring credibility to the EU ambitions in the fight against climate change.

A substantial part of the municipal energy action plans is to facilitate energy efficiency in buildings at various users. To show the way forward many municipalities has put high emphasis on implementing innovative energy saving measures in their own buildings, including implementing low energy buildings. For example the “USE EFFICIENCY” municipality Aarhus are renovating two of their administrative buildings to a low energy mode and constructing a new zero-energy administrative building. The municipality has a goal to be CO2 neutral before 2020.

Another trend is the integration of general city planning with energy planning where new city areas or renovation or existing areas are seen in relation to general sustainability requirements. In this regard sustainability is not only considered as a matter of energy efficiency and use of renewable energy resources but also a matter of  “happy” people, or in other words facilitation of good  living conditions for citizens. Sustainable energy solutions are one among several measures to obtain good living conditions in cities.