The act2 project in Nantes was designed in 2003 as an integrated approach to enrich the local energy policy stated in the local Climate and Energy action plans led by Nantes Métropole Urban Community.

It also aims at improving practices of a complete chain of actors involved in the construction process: from decision makers to citizens, passing by building companies.

In this respect, activities to be implemented focus on three main areas:

1 – Demonstration

One of the first principles of sustainable living is to make the best use of the resources that are closest at hand. Genève is putting this principle into practice using a resource that is right at its doorstep: the water of Lake Genève. The lake´s water – nearly 90 km3 in volume – has a conveniently constant temperature of eight degrees Celsius on the ground. This makes the water an ideal source of energy for heating and cooling buildings of Switzerland´s second largest city.

The Capital of Budapest is divided into 22 districts. One of the biggest local governments is the district called Óbuda – Békásmegyer. It has 127.000 inhabitants and is the 6th biggest municipality of Hungary. The City Council of Óbuda approved a development plan for the district which focuses on the energy efficient reconstruction of the building blocks as main duty. In total there are 33,981 flats built with an industrial prefabricated concrete system. These flats are in a very bad condition concerning the windows, walls, roof insulation and the efficiency of the central heating system.

The Oborishte district is one of the older parts of the city of Sofia, the capital of Bulgaria. Within Oborishte, there is a mix of residential, commercial and office functions, as well as a mix of building types (pre-war detached houses and multi-family apartment blocks). This action envisages the renovation of five apartment blocks that are rather typical for building practice both in Sofia and Bulgaria around 1970. The buildings are prefabricated apartment buildings with 7 to 8 levels, locally known as ‘panel blocks’.

Amsterdam-Noord, one of the 14 districts of the city of Amsterdam, has been developed rapidly in the post war period. For most of these buildings renovation is required, both from a technical as well as from a social point of view. Within STACCATO an approach with an enormous impact on sustainability is demonstrated in a project of 1,172 dwellings called Het Breed. Het Breed is a much talked about housing complex designed by architect Van Gool and built in the 1960’s. It exists of 11 five-storey buildings all connected by air bridges, a relic from the old airport.

Apeldoorn is situated in central Holland, to the east of Amsterdam and has around 155,000 inhabitants. It has set itself the ambitious target of becoming carbon neutral by 2020 and, through the CONCERTO project, is taking the first steps towards realising this aim by constructing 3,100 new dwellings of the highest energy standard.

In Hillerød, the regional capital of Denmark's North Seeland region, is showing that a zero CO2 community can become reality, with a development of more than 78,000 m² eco-houses that will exceed by at least a quarter of current energy efficiency standards.