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He Kainga Oranga, Housing and Health, University of Otago, Wellington

This is Case Study Two for the Research Impacts study.

He Kainga Oranga group image
Left to right: Professor Robyn Phipps, Associate Professor Michael Keall, Professor Chris Cunningham, Associate Professor Michael Baker, Associate Professor Nevil Pierse, Professor Julian Crane, Dr Manfred Plagmann, Professor Philippa Howden-Chapman, Jasmine Xu.

Participants interviewed for the case study

Principal investigator

Professor Philippa Howden-Chapman
Director, He Kainga Oranga; Chair of WHO Housing and Health Guidelines Development Group; Director of the New Zealand Centre for Sustainable Cities


Associate Professor Michael Keall
Programme Co-director, He Kainga Oranga

Associate Professor Nevil Pierse
Programme Deputy Director, He Kainga Oranga

Professor Julian Crane
Programme Co-Director, He Kainga Oranga

Professor Michael Baker
Programme Co-Director, He Kainga Oranga

Team member

Shirlee Wilton
Former Research Manager, He Kainga Oranga


Cheryl Davies
Manager, Tū Kotahi Māori Asthma Trust

Dr Manfred Plagmann
Principal Physicist, BRANZ

Summary of the impact

The He Kainga Oranga, Housing and Health research group, led by Professor Philippa Howden – Chapman at the University of Otago, Wellington, has had outstanding impact over the past two decades. Research has been directed at policy change and improving housing quality, with the ultimate goal of improving health outcomes for New Zealanders.

Factors enabling success include an interdisciplinary team researching a wide range of housing and health topics, and developing close relationships with the community, including Māori. Strong leadership and a supportive and collaborative culture have also been key.

Underpinning research

The He Kainga Oranga research group has a large body of research addressing housing as a determinant of health – based on the premise that housing quality affects the health of the inhabitants. The research includes both social and environmental elements such as overcrowding and indoor air quality. Interventions for improvement include insulation, heating and injury prevention. Ethnic inequalities are also addressed through research undertaken with Māori communities. More recent studies are investigating rental properties and legislation, and homelessness.

The first significant piece of work produced by He Kainga Oranga was the Housing, Insulation and Health Study led by Philippa and Professor Julian Crane, who co-founded He Kainga Oranga in 19981. 1350 council houses around New Zealand were retrofitted with insulation, in partnership with the Energy Efficiency and Conservation Authority / Te Tari Tiaki Pūngao (EECA).

Households with at least one occupant with a chronic respiratory condition were chosen for the intervention. Results showed that occupants’ health and wellbeing improved, as did household energy efficiency. The economic benefits of retrofitting insulation in New Zealand was found to have a benefit-cost ratio of 4:1.

Another important study, The Housing, Heating and Health Study was a randomised community trial led by Philippa and Associate Professor Nevil Pierse (2008)2. It investigated the effects of installing improved heating in 409 insulated households where there was a child with asthma. The study showed that indoor temperatures increased significantly and the health status of the children improved, with lower levels of asthma symptoms and sleep disturbances, as well as fewer days absence from school. In the Evaluation of Warm Up New Zealand: Heat Smart report, a benefit per year of $563.18 for retrofitted insulation and $4.64 for improved heating was calculated per household, due to reduction in total hospitalisations, pharmaceutical use, and mortality3.

Nevil then worked with Associate Professor Michael Keall on the Housing Injury Prevention Intervention (HIPI) study, finding that simple home repairs and modifications such as putting in grab rails in bathrooms reduced the number of falls in homes by 27 per cent4. A preliminary analysis of the pilot showed the benefit-cost ratio of this home remediation was 9:1.

Further key studies led by Professor Michael Baker focused on environmental health, infectious disease and housing. His research showed household crowding is the single biggest risk factor for meningococcal group-B infection5 and rheumatic fever6.

He Kainga Oranga have collaborated with BRANZ since their inception, and their combined research has linked aspects of building physics (such as ventilation) to health effects on occupants. BRANZ has produced a report on the role of ventilation in managing moisture inside New Zealand homes, highlighting the importance of this in creating a healthy indoor environment7. Philippa and Nevil are on the advisory board of the Warmer, Drier and Healthier Homes Research Programmes at BRANZ.

“I want people to have a better life because of the research I’ve done. I want people to be happier and healthier.”

Associate Professor Nevil Pierse – Deputy Director, He Kainga Oranga


He Kainga Oranga has received over $20 million in funding since 1998. Major funders include:

  • The Health Research Council (HRC), including $10 million in programme grants
  • The Ministries of Business Innovation and Employment; Health; and the Environment
  • Royal Society Te Aparangi
  • Cure Kids
  • Asthma Foundation
  • Accident Compensation Corporation
  • Housing New Zealand Corporation
  • Hutt Mana Charitable Trust
  • Lottery Health

Research snapshot

The key, world-leading, papers produced by He Kainga Oranga are:

  1. The housing, insulation and health study: Effect of insulating existing houses on health inequality: cluster randomised study in the community. This was the cover story of the BMJ in 20071.
  2. The housing, heating and health study: Effects of improved home heating on asthma in community dwelling children: randomised controlled trial. Published in the BMJ in 20082.
  3. The injury prevention study: Home modifications to reduce injuries from falls in the home injury prevention intervention (HIPI) study: a cluster-randomised controlled trial. Published in The Lancet in 20154.

The three main studies:

  • Have been cited in 457 academic publications indexed by Scopus.
  • Have rankings in the 98th, 84th and 97th percentiles of citations, respectively, in the field of medicine (Scopus).
  • Have had 16 media mentions, including ABC News Australia.
  • Have been cited 3 times in reports on the New Zealand Parliament website and 9 times in submissions to Parliament.
  • Are all in the top 5 per cent attention scores by

An additional 63 academic publications from He Kainga Oranga have been cited 790 times by researchers in 79 countries (Scopus).

Key reports:

  1. Warming up New Zealand: Impacts of the New Zealand Insulation Fund on Metered Household Energy Use (2011)8.
  2. Cost benefit analysis of the Warm Up New Zealand Heat Smart Programme (October 2011, revised July 2012)9.
  3. The impact of retrofitted insulation and new heaters on health services utilisation and costs, pharmaceutical costs and mortality (2011)3.
  4. Impacts of the NZ Insulation Fund on Industry and Employment (2011)10.

These reports have been cited 21 times in national and 18 times in international reports, and three times in submissions to Parliament.

World Health Organisation Housing and Health Southern Hemisphere Guidelines Launch

The Southern Hemisphere launch of the World Health Organisation Housing and Health Guidelines was held at the University of Otago, Wellington in February 2019. The guidelines group was chaired by Professor Philippa Howden-Chapman.

This event was both a celebration of the launch of the guidelines and an important step in their dissemination, as it brought together stakeholders from industry, research and politics, including Hon James Shaw, MP (Co-leader Green Party, Minister for Climate Change, Associate Minister of Statistics, Associate Minister of Finance), and Dr Ashley Bloomfield, Director General of Health.

These guidelines are the first sector guidelines produced by the World Health Organisation11.

“The World Health Organisation’s International Housing and Health Guidelines provide important and useful advice for us to bear in mind when formulating better policy for our people. They not only show us what needs to happen to provide better futures for our citizens and their families, but they help us to decide how it should happen, and perhaps most importantly, why it needs to happen.”

Hon James Shaw, MP – Co-Leader Green Party, Minister if Climate Change, Associate Minister of Statistics, Associate Minister of Finance20

Details of the impact

National impact

Policy and Programme Development

  • The Rental Warrant of Fitness programme was created through collaboration between the University of Otago and the New Zealand Green Build Council (NZGBC), in consultation with other organisations. It provides a manual and a room-by-room checklist for rental properties to ensure they are of appropriate condition13, 14.
  • Well Homes is a free programme run in conjunction with the Sustainability Trust, Tu Kotahi Māori Asthma Trust, and Regional Public Health, aiming to reduce crowding and to assist whānau in making their homes safe, healthy and dry15.
  • The Cross-Party Inquiry on Homelessness (2016) was informed by the work of He Kainga Oranga. The report’s first recommendation was to roll out Housing First as the primary response to severe homelessness16. The Housing First programme started with $2.5 million in pilot funding with a further $63.4 million invested in 201817. Through Housing First, 2,700 people now have permanent, warm, dry housing18.
  • BRANZ and He Kainga Oranga provided extensive research input underpinning the formulation of The Healthy Homes Guarantee Act 2017, which came into force on 1 July 201919. The Act legislates that landlords must comply with a healthy homes standard, including standards on indoor temperature, heating, insulation and drainage. New standards were announced in February 201920.
  • The Warm Up New Zealand programme run by the Energy Efficiency and Conservation Authority / Te Tari Tiaki Pūngao (EECA) has spent close to one billion dollars insulating over 300,000 houses through work with He Kainga Oranga15. The Government has pledged another $142.5 million to cover the costs of ceiling and underfloor insulation for thousands of low-income homeowners. That investment was boosted at the start of 2019 by nearly $5 million from community organisations, councils, charitable trusts, and DHBs20. This additional funding has resulted in 3,200 homes being insulated as of February 201920.

“I think the great thing about this programme was it pushed governments to do something that they might not have done, in a big way”.

Professor Julian Crane – Co-director, He Kainga Oranga

Health and Well-being

  • Countless individuals, including over 10,000 research participants, as well as those who have benefitted from consequential government subsidies and minimum housing standards, have benefitted from warmer, healthier homes. Improved housing standards have also helped to address health inequalities by addressing social and environmental inequalities.


  • Better housing standards reduce heating emissions, leading to impact on the environment through reduced heat loss and energy usage, thus reducing contributions to climate change.


  • The cost-benefit analysis of the Warm Up New Zealand: Heat Smart programme had showed an estimated net benefit of $950 million9 p iv. Now that the programme has been rolled out and extended, it is estimated to have delivered $2 billion of benefit to New Zealand.
  • Improved housing standards lead to less time off work or school due to fewer sick days, and a reduced burden on the health system.
  • Improvements in housing mean that energy insecurity is reduced, as well as the cost of heating for home occupants.

He Kainga Oranga members image
Members of He Kainga Oranga (Left to right): Associate Professor Nevil Pierse, Professor Philippa Howden-Chapman, Professor Julian Crane, Professor Michael Baker.

Pathway to impact

Leadership and teamwork

  • Highly accomplished leadership has been the driving force behind the success of He Kainga Oranga. This has resulted in a cohesive, high-achieving team and a culture of mutual support.
  • Team meetings are a key feature of how the team work - team members share stories of what is, and what isn’t working in their research and what help they need.

Research Framework and Quality

  • He Kainga Oranga has a firm conviction to undertake research with a strong public health focus. They have recognised that a systematic approach is key, including addressing economic, social, environmental, and cultural issues.
  • Working as an interdisciplinary team (encompassing biostatistics, public health, medicine and psychology) has enabled them to provide high-quality evidence to a wide range of research questions.
  • The ability to think ahead and think strategically, including looking at overseas research and policy, has helped to produce high-quality research.

Engagement with the community

  • He Kainga Oranga has shown a strong commitment to ongoing community engagement.
  • Engagement involved research participants, the wider community, and Māori and Pasifika stakeholders. Although engagement requires investment of money and time, it means there can be a long-lasting, beneficial relationship for both parties.
  • Community goodwill has been vitally important. Community partnerships have led to participant retention rates in the research studies of over 80 per cent.

“We adopt a philosophy of what Fred Hollows said: ‘there should be no survey without service’.”

Professor Philippa Howden-Chapman – Director, He Kainga Oranga

  • He Kainga Oranga has had meaningful, long-term relationships with Māori researchers and Māori community organisations, and the Tū Kotahi Māori Asthma Trust in particular. Feeding back on findings enables participants to feel valued and supported.

“ My big piece of advice is to develop, or establish, a meaningful relationship with Māori. If you have a Māori provider that you’ve done work with previously, don’t just finish with that study and then only go back to them maybe five years later. It goes a long way when you nurture that relationship and you keep that relationship going.”

Cheryl Davies – Manager Tū Kotahi Māori Asthma Trust

Translation into policy

  • A strategy used to increase the translation of He Kainga Oranga’s research into policy is to present findings in the form of economic analysis reports, which provide the real-world economic benefit of implementing recommended changes3, 9.
  • Research can provide compelling evidence on issues which urgently need addressing. For example, the finding that 28,000 children were hospitalised every year with housing-preventable diseases, and 853 died within a 15-year period, is difficult for policy makers to ignore.
  • Partnership with, and responsiveness to, policy makers/analysts is key to success. If a Minister wants information, then the request is prioritised.
  • The team constantly engage with policy makers to ensure that their research is kept on the agenda. This means, at minimum, three-monthly meetings with research users.

“ The real kicker to getting that impact over the line is somebody who has the ability to pick it up and make a difference, and is working in the right place to make that difference. We make a lot of noise to keep it on the agenda.”

Associate Professor Nevil Pierse – Deputy Director, He Kainga Oranga

Stakeholder engagement

  • Early and proactive stakeholder engagement has been vital, and considered the groups that may be interested in the work, and those who might be affected by potential change. Examples include community NGOs involved in housing, health, poverty or Māori development; Ministries; other government bodies (EECA, BRANZ, Housing New Zealand and Māori Boards); and visiting academics.
  • Early stakeholder engagement has also been important for strengthening grant applications as it shows that researchers have thought about who to work with and what impacts may ensue.
  • Relationships with stakeholders are built on mutual respect, co-ownership of the research, and an understanding that each party brings different skills to the table.
  • Stakeholders are invited to participate in weekly group meetings.

Capacity building

  • He Kainga Oranga is devoted to supporting students and nurturing new researchers. For example, Philippa has supervised an estimated 20 PhD, 14 Masters, 15 summer and 15 visiting students, many of whom have gone on to become team members.
  • The team is involved in Otago University’s Public Health Summer School, led by Michael Baker. The school has evolved over 12 years to become one of the largest public health summer schools in the world. 40 per cent of attendees are government staff.

Dissemination of results

  • Prior to the research there was little knowledge of housing having an impact on health, and the media has been vitally important in getting this message to the public. The team frequently issue press releases. Public interest in housing means that the researchers are often called on for comment.
  • Getting the research into the WHO guidelines was key to initiating change in policy making.

What next?

  • Nevil currently leads the Housing First research, with the aim of reducing the number of people sleeping rough in New Zealand streets by 90 per cent.
  • Michael Keall is leading a further injury prevention study, called Safety on Steps. This randomised controlled trial builds on the findings of the injury prevention study.
  • He Kainga Oranga and Tu Kotahi Māori Asthma have a project called He Tipu Manahau, which is based around the development of affordable, good-quality housing in Wainuiomata using the concept of Ko Toku Kainga.
  • Warm Hearts is a follow up study to Warm Homes for Elderly New Zealanders and is being undertaken with the support of Tū Kotahi Māori Asthma Trust. This study continues to monitor a sub- group of initial study participants, and is particularly concerned with cardiac outcomes.
  • An eviction study led by Philippa is looking at understanding the experience of those who have been evicted from their homes, as well as views from other stakeholders, including the courts, social workers and community workers.

For more infomation on He Kainga Oranga, see their website


  1. Howden-Chapman P, Matheson A, Crane J, Viggers H, Cunningham M, Blakely T, et al. Effect of insulating existing houses on health inequality: cluster randomised study in the community. BMJ. 2007;334(7591):460.
  2. Howden-Chapman P, Pierse N, Nicholls S, Gillespie-Bennett J, Viggers H, Cunningham M, et al. Effects of improved home heating on asthma in community dwelling children: randomised controlled trial. BMJ. 2008;337:a1411.
  3. Telfar-Barnard L, Preval N, Howden-Chapman P, Arnold R, Young C, Grimes A. The impact of retrofitted insulation and new heaters on health services utilisation and costs, pharmaceutical costs and mortality. 2011.
  4. Keall MD, Pierse N, Howden-Chapman P, Cunningham C, Cunningham M, Guria J, et al. Home modifications to reduce injuries from falls in the Home Injury Prevention Intervention (HIPI) study: a cluster-randomised controlled trial. The Lancet. 2015;385(9964):231-8.
  5. Baker M, McNicholas A, Garrett N, Jones N, Stewart J, Koberstein V, et al. Household crowding a major risk factor for epidemic meningococcal disease in Auckland children. The Pediatric infectious disease journal. 2000;19(10):983-90.
  6. Jaine R, Baker M, Venugopal K. Acute rheumatic fever associated with household crowding in a developed country. The Pediatric Infectious Disease Journal. 2011;30(4):315-9.
  7. McNeil S, Plagmann M, McDowall P, Bassett M. The role of ventilation in managing moisture inside New Zealand Homes 2015.
  8. Grimes A, Young C, Arnold R, Denne T, Howden-Chapman P, Preval N, et al. Warming up New Zealand: Impacts of the New Zealand Insulation Fund on Metered Household Energy Use 2011.
  9. Grimes A, Denne T, Howden-Chapman P, Arnold R, Telfar-Barnard L, Preval N, et al. Cost benefit analysis of the Warm Up New Zealand: Heat Smart programme 2012.
  10. Denne T, Bond-Smith S. Impacts of the NZ Insulation Fund on Industry & Employment 2011.
  11. World Health Organisation. WHO Housing and Health Guidelines 2018.
  12. International Council for Science. A guide to SDG interactions: From Science to Implementation 2017.
  13. New Zealand Green Building Council, University of Otago. Rental Housing WOF Assessment Checklist 2017.
  14. New Zealand Green Building Council, University of Otago. Housing Warrant of Fitness Assessment Manual 2017.
  15. Regional Public Health. Well Homes 2019.
  16. Cross-party inquiry. Ending homelessness in New Zealand: Final report of the cross-party inquiry on homelessness 2016.
  17. Cooke H. Government announces $100m plan to fight homelessness 2018.
  18. Labour Party. Wellbeing Budget 2019: At a glance 2019.
  19. Parliamentary Counsel Office. Healthy Homes Guarantee Act 2017.
  20. Shaw J. Southern Hemisphere launch of WHO International Housing and Health Guidelines 2019.