Cost optimisation and life cycle assessments of nearly zero energy buildings

The EU Horizon 2020 research project CoNZEBs (Solution sets for the cost reduction of new Nearly Zero-Energy Buildings (NZEB) - 01/06/17 to 30/11/19), identify and assess technology solution sets that lead to significant cost-reductions of new NZEBs in four EU member states (Denmark, Germany, Italy and Slovenia). All solution sets have been assessed by life cycle costs (LCC) analysis and life cycle environmental assessment (LCA) providing a longer-term perspective than the construction costs. Some results obtained are quite remarkable as they indicate that a balance point between energy saving measures and renewable energy (solar) supply has been crossed. In other words, the LCC and LCA analyses show that both for economic and environmental reasons it pays off to reduce insulation levels and introduce PV-systems and/or solar heating systems on NZEBs. Results from this work – primarily for one of the countries – Denmark – is presented.