Headed by IVL Swedish Environment al Research Institute, an initial task of the ZenN research project was to identify barriers and challenges that limit the success and expansion of Near Zero Energy Building (nZEB) renovation in Europe, providing an important input for future nZEB renovation projects.
The first objective was to identify barriers in the decision-making process that prevent renovation projects from setting high energy efficiency improvement goals. The study concluded the following main obstacles:
- The existing building structure and technical system limit the choice of technical solutions that can be used. Furthermore, where technical solutions can be found, they are often costly and not financially viable.
- Investment costs are deemed to be too high.
- Lack of knowledge and interest for energy efficiency among residents and building owners, often as a result of limited awareness.
- Buildings architectural and cultural values prevent nZEB renovation efforts.
- Ownership structure that require consensus among several homeowners can hinder nZEB renovations.
These barriers mirror the challenges faced by renovation projects with high energy efficiency goals. The main challenges of the retrofitting process include:
- Existing building structure and technical systems limit the choice of possible technical solutions.
- Building owners are unlikely to make a return on investment.
- Communication and information early in the renovation process is neglected, preventing acceptance among residents.
- An increased risk of moisture must be taken into consideration when making a building more airtight.
- A successful implementation requires extensive communication between involved organisations and actors early in the process.
The study concludes that the included countries face many similar barriers and challenges in connection to realizing residential nZEB renovations, but there are also other, equally important, challenges and barriers that are more country-specific. These often relate to respective country’s specific legislation and/or building practices.
The study includes a literature review on barriers and challenges in current practice, an in-depth analysis of financial challenges, incentives and business models for nZEB renovation as well as country studies based on interviews and workshops with 35 key persons involved in renovation projects in five countries: Sweden, Norway, Poland, France and Spain.
The complete report can be downloaded here (pdf, 1.1 MB).