CoNZEBs detected and assessed technology solution sets that lead to significant investment cost reductions of new Nearly Zero-Energy Buildings. The focus of the project was on multi-family houses. Close cooperation with housing associations allowed for an intensive interaction with stakeholders and tenants. The project started by setting baseline costs for conventional new buildings, currently available NZEBs and buildings that go beyond the NZEB level based on the experience of the consortium and available statistical data. It analysed planning and construction processes and identified possible cost reductions. An investigation of end-users experiences and expectations together with a guide on co-benefits of NZEBs promotes living in these buildings and enhances the energy performance by conducive user behaviour.
The NZEB technology solution sets include approaches that can reduce costs for installations or generation systems, pre-fabrication and construction acceleration, RES integration, and many more. Examples are pure electrical heating in combination with PV, ventilation supply through the walls to reduce the costs for ducts, larger bricks including insulation, decentral domestic hot water generation (fresh-water stations), etc. Cost savings were also possible through more efficient energy generation and distribution systems that allow for slightly reduced thermal quality of the building envelope while still meeting the NZEB requirements. All NZEB solution sets were assessed regarding investment cost savings, energy performance and applicability in multi-family houses. A life cycle assessment of different building levels and NZEBs using the solution sets provides a longer term perspective. An additional assessment took into account the changes of parameters such as primary energy factors, technology efficiencies, technology and energy costs by 2030 in order to evaluate which solution sets are future proof. Communication to stakeholders and dissemination of the project results includes events and discussions with the national housing associations.
The project consortium was comprised of leading national research organisations in the field of high performance buildings and innovative housing organisations in 4 countries.
