Passive Houses in New Zealand: a comparison between predicted and real performance through post-occupancy evaluation

Abstract

A number of Passive Houses have been built in New Zealand since 2012, implementing the standard as a voluntary certification scheme. The Passive House standard offers well-established solutions to the main issues faced by New Zealand’s housing stock: poor indoor air quality, thermal discomfort, fuel poverty and inadequate levels of insulation (Leardini, Manfredini, & Callau, 2015). However, this building standard still encounters resistance across New Zealand, as it challenges local assumptions about building construction and corresponding performance. Therefore, providing data from real case studies is essential to respond to the local skepticism, as well as enabling comparisons with the performance of code-complying dwellings. Post-Occupancy Evaluation (POE) is a key practice to verify actual performance of low-energy buildings against design expectations and simulation results. A long-term POE study was conducted on two dwellings located in Auckland and Whanganui. By collecting indoor environmental measurements, energy consumption data, and through interviews with occupants, a solid understanding of the strengths and weaknesses of each case study was achieved.