Indicators at a glance - indoor environment

This section summarises the latest Environmental Health Indicators about the indoor environment and health in New Zealand. 


A poor indoor environment can affect our health through a range of ways.

  • Household crowding increases the risk of infectious diseases.
  • Second-hand smoke exposure can cause asthma, lower respiratory tract infections, sudden unexpected death in infancy (SUDI), middle ear infection and low birth weight in children, and ischaemic heart disease, stroke and lung cancer in adults. 
  • Cold, damp, mouldy housing can worsen asthma, and is associated with asthma onset and respiratory tract infections.  

Young children and the elderly are particularly at risk from the effects of poor housing.

Indicator Key findings
Household crowding
  • About 366,000 New Zealanders (10%) lived in a crowded household in 2013. This included almost 131,000 children aged 0–14 years (about 15% of children).
  • Household crowding rates have decreased since 1991.
  • People of Māori and Pacific ethnicity were the most affected by household crowding in 2013.
Second-hand smoke exposure
  • In 2012/13, about 45,000 children (5.0%) and 105,000 non-smoking adults (3.7%) were exposed to second-hand smoke in their home.
  • The rates of second-hand smoke exposure had almost halved since 2006/07. 
  • In 2015/16, about 132,000 children aged 2–14 years had asthma and were taking medication for it. The asthma rate had increased from 14.0% in 2011/12 to 16.6% in 2015/16. Rates of medicated asthma were higher among Māori children, and children living in more deprived areas.
  • In 2016, there were 6,271 hospitalisations for asthma among children aged 0–14 years. The asthma hospitalisation rate had increased since 2001. Asthma hospitalisation rates were highest among Pacific children, and children living in more deprived areas. 
Lower respiratory tract infections
  • In 2016, there were 9262 hospitalisations for lower respiratory tract infections among children aged 0–4 years. The hospitalisation rate had increased since 2001. The hospitalisation rate was higher among Pacific and Māori children, and among children living in more deprived areas.  
Sudden unexpected death in infancy (SUDI)
  • In 2014, 45 children aged under one year old died from SUDI. Since 2000, the SUDI rate has decreased considerably, although it has increased slightly from 2012 to 2014.
  • In 2010–14, SUDI rates were higher among Māori babies, and among babies living in the most deprived areas.   
Meningococcal disease
  • In 2016, there were 35 notifications of meningococcal disease in children aged 0–14 years. 
  • The notification rate had decreased from 2009 to 2016.
  • The highest notification rates were in children aged 0–4 years, Māori children, Pacific children, and children living in the most deprived areas.   
Health burden due to second-hand smoke
  • In 2010, an estimated 104 people died from second-hand smoke exposure in New Zealand. 
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