"The overall results so far are promising and in line with expectations stated in the beginning of the project.” says Peter Sandö, task leader at IVL Swedish Environmental Research Institute. “The reduction in greenhouse gas emissions for example is encouraging. At the same time, one notable barrier is the long payoff time, confirming results from deliverable 1.2 that economics and financing opportunities are a major obstacle and challenge to nZEB renovation projects.”
The experiences and conclusions made during the process of this deliverable will be used in the development of guidelines in WP5 and replications plans in WP6. The recommendations cover such varying aspects as:
- The importance of involving building owner, tenants and expertise in energy efficiency at an early stage to find optimal solutions.
- Setting initial requirements and targets in terms of reduction in delivered energy, primary energy and GHG emissions.
- A focus on the reduction of heat losses, thereby prioritizing energy demand.
- Sufficient ventilation is crucial, when insulation thickness and airtightness increase, in order to avoid poor indoor air quality and moisture related problems.
- Heat recovery from the exhaust air should always be considered, especially in Northern Europe.
- Exhaust air heat pumps can be a cost-efficient solution for heat recovery. However, the significant increase in use of electricity usually affects the environmental performance negatively.
- Renewable energy can be produced on-site, e.g. solar energy for electricity or heating. Renewable energy can also be a part of the connected energy system, such as district heating.
- Possible collaborations between building owner and energy suppliers in finding the best possible solutions should be explored.
“This final point might turn out to be a highly relevant conclusion of the project”, says Peter Sandö. “This is a potential win-win situation, where collaboration can have great impact on district level by avoiding sub-optimisation and supporting replication”.
For more information: Peter Sandö, IVL, firstname.lastname@example.org.