Several standards regarding energy consumption have emerged in the last decade, defining increasing requirements, and culminating with the recent emergence of the “nearly zero energy” buildings concept, as described in the Energy Performance of Buildings Directive1. However, these standards are mainly focused on new buildings neglecting, most of the time, the existing ones that represent the least efficient, the largest consumers and the largest share of the building stock.
The IEA EBC Annex 56 project «Cost-Effective Energy and Carbon Emissions Optimization in Building Renovation» intends to develop a new methodology for cost-effective renovation of existing buildings, using the right balance between the energy conservation and efficiency measures on one side and the measures and technologies that promote the use of renewable energy on the other side. It aims to provide a calculation basis for future standards, which aims at maximizing effects on reducing carbon emissions and primary energy use in building renovation. The project pays special attention to cost-effective energy related renovation of existing residential buildings and low-tech office buildings (without air conditioning systems). Apart from including operational energy use, also the impact of including embodied energy is investigated in the project.
Having in mind the overall objective of slowing down climate change, measures for the use of renewable energy can be as effective as energy conservation and efficiency measures and sometimes be obtained in a more cost effective way.
To promote energy efficient buildings, with low energy consumption and energy generation onsite, innovative renovation projects are needed that can act as forerunners and inspiration but also serve as best practice examples for the expert audience and the general public.
Within this project six different Case Studies from six European countries were compiled and analyzed (see Table 1). The Case Studies are both residential and non-residential buildings, which serve as model projects for renovations in each individual country. The specific aim of the case study activity of this project is to provide significant and useful feedback from practice on a scientific basis.