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Introduction to housing quality and measuring it

This chapter presents background information on housing quality:

Defining housing quality

Housing quality has many elements, and can be defined in many ways. A targeted definition of housing quality concerns simply the quality of the internal and external structure of a dwelling and aspects of the internal environment. A wider definition may include features of the neighbourhood and concepts such as environmental sustainability. Housing quality is also referred to as housing condition or housing habitability.

Figure 1 shows some of the major components of housing quality, and some of the elements that can be included in each component.

Figure 1

Image, Components of housing quality.


Clark (2009) defined adequate housing as “protection from the cold, damp, heat, rain, wind, structural hazards, disease vectors, and other threats to health”.

However, the quality of the internal environment is also important. A definition of housing quality should ideally include a standard of adequacy relating to the quality of the external and internal structures, and the internal environment.

A challenge for everyone concerned about measuring housing quality is to first agree on a definition for housing quality. An agreed measure is essential to enable consistent collection of information. It is also important that agencies consider their priorities for data collection.

Why measure housing quality?

Housing quality became a government concern in the early 20th century

Concern about housing quality in New Zealand is not new. Infectious disease epidemics such as the great Spanish Flu epidemic in 1918/19 highlighted the importance of housing in relation to health. The New Zealand Government, concerned for the health of the population, authorised a housing survey in 1935 that focused on housing quality and crowding. Local authorities carried out this survey on behalf of central government. The Government and health authorities (Bierre, Howden-Chapman, Signal, Cunningham, 2007) were concerned over the presence of urban ‘slum’ areas.

By March 1939, housing surveys had been carried out in 115 of the 119 local areas. The results covered 225,363 dwellings, where 901,353 people lived (Taylor, 1986). Of buildings used as dwellings, 31,663 were classed as unsatisfactory but repairable; 6,827 were totally unsatisfactory. There were 9,835 overcrowded dwellings with 14,761 surplus persons in them. These surveys remain the only comprehensive housing surveys ever carried out in New Zealand.

After World War II, the New Zealand Government introduced regulations about housing quality, based on this housing survey. The Housing Improvement Regulations 1947 (amended 1975) established the minimum standards for housing in for bathroom facilities, light and ventilation, and room size. It also included a measure of crowding, and designated the minimum provision of facilities (a household should have one bathroom and toilet for every seven people). The regulations have some clear directions about housing quality including the provision of sewerage, freedom from dampness, and maintenance to an acceptable standard (see appendix 1).

Although no comprehensive housing surveys have been carried out since the 1930s, a number of studies have highlighted the issue of poor housing quality in New Zealand. These studies have shown that New Zealand houses tend to be too cold. The Household Energy End-Use project showed that one-third of households in the South Island had an average winter temperature in the living room of below 160 Celsius (Stoecklein et al, 2002). The World Health Organisation recommends a minimum indoor temperature of 180 Celsius, with a warmer minimum temperature for the elderly and very young.

Links between housing and health lead to a greater focus on housing quality

A considerable body of New Zealand and international literature links poor housing quality with poor physical and mental health. The strong link between damp housing conditions and poor respiratory health is evidenced in numerous New Zealand and international studies.

Poor health results in increased hospital admissions and more absences from school and work, with implications for the economy. A recent evaluation of the Warm up New Zealand: Heat Smart programme (Grimes et al, 2012) showed a 5:1 cost benefit ratio for insulation. A study of 58,000 children in various countries showed “indoor mould exposure was consistently associated with adverse respiratory health outcomes in children” (Antova et al, 2008).

Antova et al (2008) also demonstrated a relationship between crowded living conditions and asthma. In New Zealand, Keall et al (2012) estimated that, using their Respiratory Hazard Index, for each increase in the hazard index there was a corresponding rise in the experience of wheezing or asthma. Research shows New Zealand has higher hospitalisation and mortality rates in the winter, which is likely to relate to poor housing quality (Barnard, 2009, quoted in Canterbury District Health Board, 2012).

Clark (2009) notes that damp housing affects physical health because it has the potential to increase dust mites and moulds, both of which are allergenic. Figure 2 shows the presence of black mould in wall linings. Hidden housing issues such as mould can adversely affect people’s health.

Figure 2
Example of black mould in wall linings

Image, Black mould in wall linings.

Piatt et al (1989, quoted in Clark, 2009) shows people living in damp and mouldy dwellings are more likely to report nausea, vomiting, constipation, blocked nasal passages, breathlessness, backache, aching joints, and fainting than people living in drier dwellings. The OECD (2011) emphasises the importance of measuring housing quality because “it is a major driver of health status with effects for both mental and physical health”.

The strong body of evidence showing the association between housing quality and health has promoted a growing interest in housing quality. Researchers in New Zealand have identified rental housing and rural properties in low socio-economic areas as particularly associated with low-quality housing. The He Kainga Oranga Housing and Health research programme has shown that intervention (insulation, ventilation, heating, and crowding reduction) has resulted in improvements in health (Howden-Chapman, Baker, Bierre, 2013). Their work was published as the leaky homes issue was revealed in New Zealand.

Poor housing quality has economic as well as health impacts. The ‘leaky homes crisis’ (where a relaxation of building standards resulted in a number of houses being built that were not weathertight) has had a significant impact on the economy. The New Zealand Productivity Commission (2011) noted the “leaky homes crisis has been estimated at costing $11.3 billion cost (2008 dollars)”. Housing is affected by the structure and maintenance of the building (eg leaking roofs) and by the way people live in a dwelling. Dampness and mould will be exacerbated if, for example, inhabitants dry clothes inside, do not ventilate the dwelling, or use unflued gas heaters. Energy efficiency is considered an important indicator of housing quality as uninsulated dwellings are difficult and expensive to heat, and contribute to dampness and cold within a home.

Housing quality has been identified as a major information gap in the official statistical system, first in the 2009 Review of Housing Statistics (Statistics NZ, 2009b) and then in the revised list of Tier 1 Statistics 2012 (Statistics NZ, 2012). Housing quality is seen as a major issue in New Zealand, partly because of concern over ‘leaky building syndrome’, following the revised building codes of the 1990s, and the consequent cost to the economy, but also because of the public-health issues associated with poor housing quality.

The strong link between damp housing conditions and poor respiratory health is clear in many New Zealand and international studies. Poor health results in increased hospital admissions and more absences from school and work, with implications for the economy. A recent evaluation of the Warm Up New Zealand: Heat Smart programme (Grimes, et al, 2012) showed a 5:1 cost benefit ratio for home insulation. 

Reviews of housing quality in New Zealand

Several major reviews and initiatives across government in recent years have identified the importance of housing quality statistics. 

The 2009 review of housing statistics

Review of housing statistics report 2009 (Statistics NZ, 2009b) presented the results of extensive consultation with both government and non-government organisations with an interest in housing. Among other recommendations, the review identified housing habitability as a key topic and recommended that:

The Department of Building and Housing, the Building Research Association of New Zealand (BRANZ), and Statistics NZ should work together to investigate improvements to existing data sources (survey or administrative) on the physical quality of the national housing stock.

The review also noted that:

The physical quality of housing is of public policy interest because of its links with individual and family well-being. Investing in good quality housing can result in improvements in health outcomes among groups that are living in badly constructed and older homes. Homes that need repair can increase the risk of injury for occupants; these homes are associated with cold and damp living conditions and are a threat to health. Poor health outcomes can have a flow-on effect to outcomes in other areas, such as education, paid work, and economic standard of living. Research shows that housing conditions and the neighbourhood in which a child is raised affect that child’s well-being…a major British cohort study shows that the effects of poor housing conditions are cumulative over life.

The review also suggested different aspects of housing quality that could be collected, including the physical attributes of dwelling stock and the characteristics of inhabitants (see Suggested key aspects of housing quality information to be collected – 2009 Review of Housing).

The importance of the review’s recommendation was highlighted when housing quality was also included in the revised list of Tier 1 statistics in 2012 (Statistics NZ, 2012). 

Progress since the 2009 Review of Housing Statistics

The Department of Building and Housing (now part of the Ministry for Business, Innovation and Employment) agreed to develop measurement of housing quality in conjunction with the Building Research Association of New Zealand (BRANZ) and Statistics NZ. In 2010, the Department of Building and Housing funded an increased sample for the BRANZ house condition survey, which included some rental housing for the first time. This survey has provided some information about housing quality in New Zealand, but has a very small sample.

See New Zealand House Condition Survey (BRANZ) for further information. 

2012 Review of Tier 1 statistics

Tier 1 statistics are the most important statistics, essential for understanding how well New Zealand is performing. Tier 1 statistics:

  • are essential to critical decision-making
  • are of high public interest
  • meet expectations of impartiality and statistical quality, in accordance with the Principles and Protocols for Producers of Tier 1 Statistics
  • require long-term data continuity
  • allow international comparability
  • meet international statistical obligations.

In August 2012, Cabinet approved the new 2012 Tier 1 list. The list was broadened and balanced, compared with the previous list of Tier 1 statistics, to better reflect a wider range of government and public concerns, and to address statistical gaps identified by producers and users.

The revised list is more aspirational than the previous list. The revised list includes statistics that do not currently exist or are not considered of sufficient quality, scope, or coverage to be regarded as Tier 1, but are considered essential to develop. These new ‘development’ statistics will be introduced over the next few years as research and development is conducted to identify appropriate statistical measures and ensure they are produced to the required standards.

Recent initiatives on housing quality in New Zealand

The Children's Commissioner, and the Expert Advisory Group on Solutions to Children’s Poverty (2012) recommended that a housing quality standard for rental properties be developed:

Recommendation 20: We recommend that the government ensure all rental housing (both social and private sector) meets minimum health and safety standards, according to an agreed Warrant of Fitness, such as the Healthy Housing Index. These standards should be monitored periodically and effectively enforced, and gradually increased over time.

Dr Russell Wills, the Children’s commissioner (quoted in National Business Review, 2013, 3 November) noted:

The patients that I see typically have cold, damp houses, they can’t afford to go to the GP, they often can’t afford to do the basics that our kids would take for granted, like to go on school trips and have stationery and a uniform, shoes that fit. You know, their houses really are in a shocking state. Most kids who are living in poverty live in private rentals, not state rentals but private rentals, and those houses are in appalling state. So having a warrant of fitness again is one of those very practical recommendations that the Expert Advisory Group recommended. We’re going to see that in state housing first, and then we need to see it in private rentals too. We know that will make a big difference.

In the May 2013 budget, the Government announced they would develop a housing warrant of fitness. They plan to apply this warrant of fitness to Housing New Zealand properties in the first stage, and may extend it later to all rental housing. A forum involving a range of organisations including BRANZ, Otago University, central and local government, and a range of other groups has been established is to be established to help develop the Housing Warrant of Fitness.

Both international and national studies show links between housing quality, crowding, and health as shown in the section: Links between housing and health lead to a greater focus on housing quality. For example, research by Grimes et al (2012) has shown strong health benefits for insulation. The cross-agency reference group on rheumatic fever (made up of the Ministries of Social Development, Education, and Health, Statistics NZ, the Police, and the Social Sector Forum) has also indicated an interest in housing quality measures. The group’s aim is to assist “government agencies in working towards the Better Public Services goal of reducing rheumatic fever by two thirds to 1.4 cases per 100,000 per year by 2017” (Better Public service: Rheumatic Fever Prevention Programme, 2012). Among other initiatives, the group is looking at measures to improve housing quality and reduce household crowding.

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