Cities substantially contribute to European air pollution as they are the source of about 36% of the total CO 2 emissions. Modern cities therefore raise sustainability concerns.

Imagine a city could halve its energy consumption, costs and greenhouse gas emissions. This would get closer to levels that would ensure sustainability of resources.

Those who live in low-energy buildings are not experts. But energy professionals have been aware of the importance of meeting their needs, right from conception stage.

Tackling energy loss from buildings is one of the key objectives to reach greater sustainability, when it comes to energy consumption.

Buildings are responsible for 40% of Europe’s total primary energy consumption. Residential buildings represent about 80% of the total building stock.

The heating and cooling of buildings take a large share in the energy consumption in Europe . The average energy consumption in the non-residential sector, such as public and industrial buildings, is estimated to be at least 40% greater than in the residential sector.

Restoring historic buildings and saving energy at the same time is now a reality. Passive house window expert Franz Freundorfer developed the heat-saver for the Waaghaus in Bolzano, a building from the 13th century .

A well-accepted measure for climate protection involves reducing greenhouse gas emissions . And buildings have the greatest energy saving potential, according to the official EU Energy Efficiency Plan 2011 .

Historical buildings and town quarters are an integral part of the European cultural heritage. However, such buildings are often not very energy efficient and thus contribute substantially to the emission of greenhouse gases.

The construction of a building does not only start with its design by architects and engineers.

The overall building stock represents about 40% of the EU’s energy consumption. It also produces about 36% of its total CO2 emissions. Besides, new buildings only account for 1% to 1.

Ulrich Filippi Oberegger is a senior researcher in the energy management in buildings group of the Institute for Renewable Energy of EURAC Research . He tells youris.

The building sector has traditionally been fragmented. Many different actors are involved at different stages, from the design to the performance monitoring stage.

EnginSoft , is an Italian consultancy specialised in computer-aided-engineering. It has experience of contributing to the development of low energy buildings, under the EU-funded DIRECTION research project.

Achieving nearly zero energy consuming cities: this is the goal of three large scale district renovation projects. They are currently being tested in Valladolid, Spain, Genoa, Italy and Kartal - Istanbul, Turkey.

Urban mining is increasingly being taken seriously by industry because it gives access to materials—such as expensive metals used in electronics—that are buried in waste tips and landfills.

The NuOffice in Munich is an office building and one of the showcases of the EU-funded project DIRECTION . The first building phase was completed in 2012, the second and third will be completed in 2014 and 2015.

Much effort has been put into its planning and construction to reach this high-level of sustainability, which makes it the most sustainable newly erected office building worldwide , according to LEEDS standards.

To make a building sustainable, taking into account its climatic conditions is key. No better examples than the three showcase buildings under the EU funded  DIRECTION project.

Sustainable buildings partly depend on control strategies to be energy efficient.