Technical barriers are inevitable with the introduction of new technologies and can include both problems associated with low energy housing design, technological systems and construction materials, as well as the lack of knowledge and skills in the building chain. The current levels of knowledge and experience vary widely between housing providers and Member States. Competencies in large-scale refurbishment are now highly concentrated within the Public, Cooperative and Social Housing sector in virtually all Member States, since this work is scarcely carried out in the private sector.

A lack of specific knowledge on the part of the built environment professionals, including planners, building managers and architects had led to problems with poor design and the unsuccessful introduction of new technologies. It was particularly felt that there was inadequate knowledge on how to identify the best technology mix to deliver nZEB and also an understanding of how to assess the cost-effectiveness of the products. An anticipated additional area of inadequate capacity is likely to be found in the public officials who will be called upon to manage the forthcoming nZEB requirements.

The skills and knowledge of the construction workforce and their supervisors who actually carry out the construction was also found to be lacking in some Member States due to the very low levels of training in these systems. Similarly, skills and experience were lacking in those required to service and maintain the new heating and ventilation systems which require regular cleaning, service and repair to ensure their proper functioning.