Ten questions concerning cost-effective energy and carbon emissions optimization in building renovation

In European countries, the majority of the buildings is more than 20 years old and buildings are the major energy consumers due to their general low energy performance. To achieve the EU 2020 and 2050 targets for emissions reduction, it will be necessary to take actions for large-scale renovation of the existing building stock. However, today?s standards are mainly focused on new buildings, guiding the improvement of the energy performance of the existing buildings into expensive processes and complex procedures that seldom are accepted by users, owners or promoters. For these buildings, the range of technical solutions is short and may lead to ancillary works that result in a relevant increase in costs. In this context, the IEA EBC Programme launched the Annex56 project (Cost Effective Energy and Carbon Emissions Optimization in Building Renovation), with the goal of investigating solutions and produce guidance suitable for European residential buildings, taking into consideration not only the benefits related to energy and carbon emissions reduction, but also the added value resulting from the renovation process. Considering the goal of reducing carbon emissions, measures that promote the use of renewable energy can be as effective as energy conservation and energy efficiency measures. In this sense, it is important to determine the optimal balance between the minimization of energy demand and the use of renewable energy. The optimization process has to explore the full range of cost-effective reduction of carbon emissions and energy use and also to take into account the additional benefits and the overall added value achieved by the building within the renovation process as well as the increasing relevance of the embodied energy associated to the materials and systems used in the interventions. (undefined)