The near Zero Energy Building standard and the Passivhaus standard – a case study

The EU has mandated that all buildings are built to the near Zero Energy Buildings (nZEB) standard from 2020. The Passivhaus standard has been in existence for over 25 years and potentially offers a tried and tested method of achieving nZEB.This paper explores if there is a performance gap between the PH standard and the nZEB standard. Further, analysis is carried out based on monitoring results from a real building: a 103m2 three bedroom dwelling located in Ireland. The comparison of the two standards is carried out with particular focus on the assumed and recorded indoor temperature assumptions and heating periods for both standards. The analysis looks at the actual indoor climate experienced, based on the following recorded metrics which are being gathered at five-minute intervals:a. occupancy profileb. indoor air temperaturec. indoor relative humidityd. indoor carbon dioxide concentrationse. outdoor temperaturef. outdoor relative humidityg. wind speedh. barometric pressurei. energy consumptionBased on the above metrics a discussion takes place on the energy and IEQ performance in the context of the performance mandated by the respective standards in the quest to deliver Passive and Low Energy Architecture.