The realized ZERO-PLUS buildings exceed the state of the art by achieving:
• Net regulated energy usage ≤ 0-20 kWh/m²/y
• Renewable energy generation ≥ 50 kWh/m²/y
• 16% reduced investment cost compared to a regular NZEB
and result in a total of 46.3tonnes of CO2 offset corresponding to104.6 kgrCO2/m2/y saved.
The four case studies demonstrate that storage for supplemental renewable energy generation is essential for increasing self-consumption of renewable energy in all locations and for shifting the load to meet peak demand.
Post-Occupancy Evaluation analysis confirmed the high quality of the case studies’ design, detailing and construction. In particular, it showed high satisfaction with individual parameters (ventilation, temperature, noise, lighting, odours) and overall satisfaction with the buildings. Thermal and acoustic advantages of building envelopes, and lighting were praised in a number of occasions. Implemented renewable energy systems were indicated as one of the reasons for changing behavioral patterns. Building users indicated preference to operate windows and doors in order to achieve thermal comfort and improve Indoor Air Quality (IAQ) before operating HVAC.
The tools and methods tailored to the settlement level comprising the ZERO-PLUS approach, the acceptable as-built results and the developed methodology for the transition from building to settlement level successfully support the transferability and replicability of the ZERO-PLUS approach in different contexts, namely:
• retrofit of existing settlements
• additional uses (e.g. schools, office buildings, etc.). In fact, expansion to include additional uses is likely to make the approach even more effective given the larger scale of many such buildings, and the fact that they are often located within campuses in which settlement-level solutions could be more easily applied
• different building types – both public and private housing, single and multi-unit housing –
• different climatic regions with different heating and cooling requirements.
