19-20 March 2018, Workshop, Wellington (NZ) - Towards higher-performing buildings: The role of airtightness and ventilation
19 - 20 March 2018 | Wellington, New Zealand
Museum of New Zealand Te Papa Tongarewa
08:00 Europe/Brussels

The objective of this AIVC workshop was to discuss and identify ways to improve the quality of our homes with respect to airtightness and ventilation, as well as discussing the impact suboptimal performance has on energy consumption and health of the occupants. Also of interest were the impacts of mandatory airtightness targets and how best to implement these, if at all. 

Specific topics

  • Indoor air quality in schools and residential buildings
  • Ventilation and its impact on energy and health outcomes for occupants
  • Airtightness of New Zealand buildings - trends and requirements


New Zealand homes and apartments have become more and more airtight and have reached a level of airtightness that requires dedicated ventilation. Despite the fact that there is no airtightness requirement in the New Zealand Building Code, new homes regularly reach an airtightness level of 2-3.5 ACH50. This can be a welcome trend as it allows controlled ventilation and therefore control of the energy demand of the building. Many newly built homes, however, experience excess moisture and mould problems in living areas and/or roof cavities, due to a combination of occupant behaviour and a lack of ventilation.

The goals of a healthy home environment and energy efficiency can sometimes pull in opposite directions, requiring us to find a trade-off between health and energy saving.

Do we need dedicated airtightness and ventilation targets in the Building Code to reach an optimal set point for ventilation related energy use and health outcomes? How can this be achieved?


The workshop was organised by INIVE EEIG on behalf of AIVC in cooperation with ASHRAE and BRANZ.


You may download the workshop presentations from the table below

Context and policies  
The involvement of New Zealand in IEA Energy in Buildings and Communities projects | Michael Donn (New Zealand IEA EBC Executive Member) Pdf
Overview of the Air Infiltration and Ventilation Centre (AIVC) and TightVent | Peter Wouters (AIVC Operating Agent) Pdf
Activities of ASHRAE related to ventilation and airtightness | Bjarne Olesen (ASHRAE/DTU) Pdf
Overall situation in New Zealand regarding energy performance (policy, standards, regulations, …) | Christian Hoerning (EECA) Pdf
Indoor Environmental quality, ventilation and health  
Why do we care about IAQ Metrics? | Max Sherman (LBNL) Pdf
Indoor Environmental Quality: Comfort-Health-Productivity | Bjarne Olesen (ASHRAE) Pdf
The health effects of sub-standard housing on children | Nevil Pierse (He Kainga Oranga) Pdf
Annex 68 presentation ( Design and Operational Strategies for High IAQ in Low Energy Buildings) | Jelle Laverge (Ghent University, Belgium) Pdf
Indoor climate and air quality  
Future Cooling Needs of Buildings and the role of ventilation | Mat Santamouris (University of New South Wales) Pdf
Indoor climate and ventilation in school buildings | Roby Phipps (Massey University) Pdf
New Indoor Air Quality and Thermal Comfort (IAQ&TC) guidelines for school buildings | Bernie Cruise (Ministry of Education) Pdf
Methodology to assess the exposure to cooking emissions in combination with the efficiency of range hoods | Willem De Gids (VentGuide, Netherlands) Pdf
Ventilation performance  
Demand controlled ventilation: design guidelines and performance characterisation in Belgium | Arnold Janssens (Ghent University, Belgium) Pdf
Expected temperature distribution in NZ homes using MVHR | Peter McDowall (BRANZ) Pdf
Building and ductwork airtightness  
Measuring airtightness of dwelling with a domestic ventilation system | Wouter Borsboom (TNO, Netherlands) Pdf
Airtightness in New Zealand homes and apartments | Steve McNeil (BRANZ) Pdf
“Lessons in air tightness and air quality from the Japanese sick house experience” | Andy Russell (Proctor group) Pdf
Air Tightness Requirements in For High Performance Homes in Mild Climates | Iain Walker (LBNL) Pdf
Quality assurance for ventilation and airtightness  
Quality and compliance of ventilation systems : on-going developments, lessons learnt, future challenges | Peter Wouters (AIVC Operating Agent) Pdf
Ventilation, moisture and mould in old and new homes in NZ | Manfred Plagmann (BRANZ) Pdf
Ventilation and Airtightness, different relationship for different quality of buildings | George Zhang (Center for Sustainable Built Environment, Hunan University) Pdf