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The next level of energy performance of new buildings within the European Union will be the Nearly Zero-Energy Building (NZEB). A lot of work has been spent on pilot and demonstration buildings on this and even higher energy performance levels throughout many EU countries. However, most of the high performance buildings realised so far result in additional investment costs when compared to the current national minimum energy performance requirements. The considerably higher investment costs are one of the main barriers to the early application of the NZEB-level in Europe. The EU Horizon 2020 project CoNZEBs works on technical solution sets that result in lower investment costs for NZEBs, bringing the costs close to those of conventional new buildings. The project focus is on multi-family houses. In each of the four participant countries Germany, Denmark, Italy and Slovenia a team of researchers is analysing which sets of market-ready technologies at the building envelope, the services systems for heating, domestic hot water, ventilation and cooling (where required) in combination with renewable energy systems can fulfil the NZEB requirements at lower costs than those incurred by the national mainstream NZEB application. Additional efforts are being spent on the life-cycle costs and the life-cycle analysis of the solution sets, as well as on the impact of future developments of primary energy factors, energy costs and technology efficiencies. Since details of the CoNZEBs work are presented in several additional papers, this document gives an overview of the different tasks and results that are available so far. The next level of energy performance of new buildings within the European Union will be the Nearly Zero-Energy Building (NZEB). A lot of work has been spent on pilot and demonstration buildings on this and even higher energy performance levels throughout many EU countries. However, most of the high performance buildings realised so far result in additional investment costs when compared to the current national minimum energy performance requirements. The considerably higher investment costs are one of the main barriers to the early application of the NZEB-level in Europe. The EU Horizon 2020 project CoNZEBs works on technical solution sets that result in lower investment costs for NZEBs, bringing the costs close to those of conventional new buildings. The project focus is on multi-family houses. In each of the four participant countries Germany, Denmark, Italy and Slovenia a team of researchers is analysing which sets of market-ready technologies at the building envelope, the services systems for heating, domestic hot water, ventilation and cooling (where required) in combination with renewable energy systems can fulfil the NZEB requirements at lower costs than those incurred by the national mainstream NZEB application. Additional efforts are being spent on the life-cycle costs and the life-cycle analysis of the solution sets, as well as on the impact of future developments of primary energy factors, energy costs and technology efficiencies. Since details of the CoNZEBs work are presented in several additional papers, this document gives an overview of the different tasks and results that are available so far.

Nearly zero energy buildings (NZEBs) are required as the minimum standard for all new buildings in Europe by January 2021. NZEBS should, according to the Energy Performance of Buildings Directive (EPBD) [1], be cost optimal, i.e. the cost of constructing and operating the building over its lifetime should be at its minimum. The EU Horizon2020 research project CoNZEBs, identify and assess technology solution sets that lead to cost reductions of new NZEBs in four EU member states. Focussing on buildings that comply with national NZEB requirements, designers can easily ignore alternative solutions that make the building cheaper while remaining within national requirements. This is not done intentionally, but primarily due to use of a traditional design thinking where optimisation is done on component level instead of a more holistic approach. Changing one building component may influence the cost and performance of other components. These alternative solutions take offset in a typical national multi-family building design and analyses the different lifetime costs in terms of costs for construction, and energy. Analyses of costs in different countries reveals different solutions sets being optimal. In CoNZEBs we compare different solution sets and investigate the possibility for “exporting” solution sets from one country to another.