Nearly Zero-Energy buildings
Buildings currently account for 40% of energy use in most countries, putting them among the largest end-use sectors. The International Energy Agency (IEA) has identified the building sector as one of the most cost-effective sectors for reducing energy consumption, with estimated possible energy savings of 1 509 million tonnes of oil equivalent (Mtoe) by 2050. Moreover, by reducing overall energy demand, improving energy efficiency in buildings can significantly reduce carbon dioxide (CO2) emissions from the building sector, translating to possible mitigation of 12.6 gigatonnes (Gt) of CO2 emissions by 2050 (IEA, 2010).
According to Article 9 of the Energy Performance Buildings Directive (EPBD), Member States shall ensure that by the end of 2020 (2018 for public buildings), all new buildings are Nearly Zero-Energy Buildings (NZEB). However, progress is slower than expected and requires the development of market ready cost reduction solutions. Cost-effective integration of renewable energy production elements into NZEB in a form that fits with the construction industry’s design and procurement process is a major challenge. Widespread application and roll out of means for cost effective development of NZEB would accelerate the market. The significant cost reduction that is required to mainstream NZEB by 2018 is likely to revolve around processes rather than technologies. There is an additional need to look beyond NZEB performance with a longer term perspective. Support is also needed to ensure that end users and occupants appreciate the role they play in the building's energy performance.
Cost reduction and energy savings should apply to the whole life-cycle of the building. This challenge addresses the whole of the construction process, including inception, planning, design, pre-fabrication, on-site operations and post-construction reviews.
It is one of previously popular idea of Passive House (Passivhaus in German) refers to the rigorous, voluntary standard for energy efficiency in a building. It results in superefficient buildings that require little energy for space heating or cooling. In addition to very strict energy limits, the Passive House standard requires airtight construction and high-performing thermal envelope properties. Passive House buildings provide a high degree of thermal comfort, superior indoor air quality and are detailed for durability
The Passive House standard is not confined to residential properties; several office buildings, schools and even a supermarket have also been designed and constructed to meet the standard. Although it is mostly applied to new buildings, it has also been used for refurbishments.