Survey and solutions for potential cost reduction in the design and construction process of nearly zero energy multi-family houses

While the day in which nearly zero energy buildings is quickly approaching, their construction cost remains higher than minimum requirements' ones, in this framework operates CoNZEBs (Solution sets for the cost reduction of new Nearly Zero-Energy Buildings) Project, funded EU Horizon 2020. This paper explores a critical point identified by the project: potential cost reductions in the design and construction process. Starting from current costs and assessed the lack of available data, a survey is carried out focusing on two main stakeholders: i) design and planning process actors; ii) construction companies and contractors. About 100 answers are collected within the participant countries (Denmark, Germany, Italy, Slovenia), providing insights about issues and potential solutions for the process cost reductions. The results show differences among countries in terms of expectations for the potentials solutions, mainly related to the national market characteristics. The survey also shows the critical issue of the increase for construction costs respect to the originally planned ones Another session presents the impact of exemplary solutions aimed at optimising the design and construction process costs; they are grouped in three categories: specific building envelope and energy system technologies, specific design solutions, innovative project management systems. Quantitative examples are provided for each category.