In terms of value for money, rents are lower in high income areas because the main reason for ownership of the property by the landlord is as an investment, the rental income is secondary, competition is not high and so rents are relatively lower on higher value properties. In low income areas, rent is the main consideration for purchase by the landlord and competition for the few places available is high which pushes up rents.
Research shows that people spend at least 70 per cent of their time at home, and this rises to almost 90 per cent for the very young and the elderly. For this reason alone, the standard of housing is a vital factor in the health of the nation. Professor Howden-Chapman pointed out a number of health factors associated with poor housing - cold indoor air is harder to heat; mould grows better in damp air; viruses survive longer on cold surfaces.
It is increasingly common to have several families in one house to reduce individual rental costs. Most houses only have one heated room, and the occupiers tend to crowd together in that heated room, making the spread of diseases - especially respiratory - more likely. Cold stresses the immune system and moving between heated and unheated areas such as the bathroom can cause heart disease flare-ups.
An obvious question is whether investment in quality, cheap housing would reduce health service costs in the longer term. For more vulnerable people - and especially those suffering from mental illness and the aged - the effects of poor housing can be profound, driving them further into despair and becoming less able to cope.
The level of superannuation payments is based on a model which is now out of date. It was assumed that people reaching retirement age would own a mortgage-free home, but this is increasingly not the case.
Elderly people in rented homes spend a disproportionate amount of their income on rent and less than is necessary on heating.
Professor Howden-Chapman presented some alarming statistics. In 1990, 30 per cent of new homes were affordable by the lowest 25 per cent of income earners. In 2015, this had dropped to 5 per cent, with 60 per cent of new homes only affordable by the top 25 per cent of earners. In 2015, 43 per cent of mortgages in Auckland were lent to property developers and only 12 per cent to first home buyers.
Professor Howden-Chapman spoke about situations which are nonsensical - state housing refurbished to a good standard and then moved into storage where it stands empty; government spending $2 billion per year on accommodation supplements with no requirement for minimum housing standards.
Professor Howden-Chapman hammered the need for creative forward thinking to reverse a situation that, without action, is only going to get worse.
*Philippa Howden-Chapman presented a public lecture on New Zealand housing issues - organised by the Whanganui Science Forum - last week at the Davis Lecture Theatre. A professor of public health at the University of Otago, and director of the New Zealand Centre for Sustainable Cities, Professor Howden-Chapman is the author of the book Home Truths, Confronting New Zealand's Housing Crisis.
*Frank Gibson is a semi-retired teacher of mathematics and physics who has lived in the Whanganui region since 1989.