In this edited extract from his yet-to-be-published journal article Density, the Sustainability Multiplier: Some myths and truths with application to Perth, Australia, Professor Peter Newman reveals the top 10 myths regarding high density.
Myth 1: High density housing is bad for your health and creates social problems
There is no evidence to suggest that health gets worse in dense housing. Most people in the world live in high density housing, though there are huge variations in density. There is no correlation between these levels of density and health. Health levels relate mostly to income.
Poverty is the biggest cause of ill health. Hong Kong has 300 people a hectare – nearly 30 times Perth’s density – but has high life expectancy and low infant mortality like Perth.
There is no evidence social problems like crime are increased in high density areas. Crime is also mostly related to poverty. In America, the higher the density the lower the crime rate though this is more than likely because low density cities are poorer. There is some evidence that low density areas have greater obesity and depression due to less walkability, and higher crime rates due to less “eyes on the street”.
Myth 2: High density housing will lower land values and create slums
There is no evidence to support land values collapsing when higher density housing goes into an area. In most cities, land values are related to amenity – access to recreation sites, the ocean, good schools, to services like health and other employment opportunities and close to rail lines. As people move to amenity areas the pressure to subdivide goes up. If zoning is increased then land values increase.
Even in the low density cities of America, the highest density areas like Manhattan, inner San Francisco or Washington DC are, in general, the highest value land. If anything, there is a problem with density causing land values to go up so much that they cause poorer people to be displaced as they can’t pay the rates or rents become too high. This gentrification is why a proportion of affordable housing is on the agenda for most planners dealing with the density issue.
Myth 3: Nobody likes high density housing
There are many cultures who like dense, high-rise housing in Asia, Europe and Latin America. There is a long tradition of living in close proximity for security and ease of access between friends and family. English traditional culture favours the village and rural spaciousness (in literature this is called “pastoralism”), especially after the industrial revolution with its dense slum housing. There has, however, always been a more urban tradition in cities like London and Manchester with their amenity and attractions, and in the US.
In Australia many migrants from the UK were escaping the poverty of public housing and came seeking a suburban life. Housing markets in Australia, and more dramatically in Perth in recent years, have increased in the proportion of households who favour location over housing type, that is, they choose high density because of its access to amenity. Location has always meant a lot in cities.
Many people will want to remain in a low density house but they appreciate the benefits that higher density centres nearby can bring to their area including better transit, shops, childcare and even aged housing options. As dense centres are built the attitudes to them start to soften.
Myth 4: The high density problem is caused by population and this should be stopped or people put in country towns
Population movements are mostly part of the global economy and few countries are trying to opt out of that like North Korea. Stopping participation in the global economy means that cities go into immediate economic decline. Some cities like Detroit in the US and Liverpool in the UK did not adapt to the changing global economy and so went into decline. Few communities or politicians are going to accept economic decline as their policy for the future.
Perth, for example, is a boom town and its population growth is mostly caused by overseas immigration. Australia has always been a migrant country and the growth of the economy is linked to this flow of people from across the world who have followed the new jobs. Mostly, people come to Australia who have specific skills or business investments. Refugees are a small proportion and are part of international law obligations. Stopping people coming to Perth once in Australia is not legal. If the economy crashed then the population “problem” would be solved – it would transfer to somewhere else. Perth’s economy is unlikely to be used as an immigration control device.
Some Australian migrant schemes require new arrivals to live in country towns. Some stay (for example, Katanning has a multicultural mix of workers) but most move to cities like Perth where the economic opportunities, educational opportunities and health opportunities are greater. Country towns in Australia are mostly in decline and few policies have worked to reverse this decline. Government incentives in terms of country town housing, grants, etcetera, have never changed Perth’s overall growth. When Western Australia grows it is because Perth is growing.
Myth 5: High density housing removes trees, places for children to play and opportunities to grow food and collect rainwater
The new world cities built with the car after World War II had large allotments. Australian suburb allotment size of a quarter-acre or 1000 square metres was a substantial area designed to cope with a septic tank’s overflow, to have a rainwater tank, hopefully a vegetable garden, some trees and plenty of grass for children to play on – and of course, a large garage for several cars. This lifestyle was heavily subsidised in the post-war years for returned service men and continues to be subsidised as it provides for the unique “Australian lifestyle”.
However, like all new world cities, Australian cities now have sewerage systems and good water supplies and the size of the houses have slowly grown so they are now four times bigger than houses in the 1960s, while the block size has reduced to around the 400 sq m mark. Still the campaign rhetoric of save our suburbs groups is to maintain the low density suburb as though they remained unchanged since the 1950s.
Every decade of housing reaches a point where redevelopment is necessary. The model that seems most acceptable to low density-dominated local planning systems in the US and Australia is to allow backyard infill with several small units. In this way all the trees, grass and vegetable patches are replaced with brick houses, bitumen and brick pavers. Apparently this is acceptable because it is not high rise. However it adds very little to an area because there are no infrastructure changes or service improvements.
High-rise that enables better infrastructure and services, and which can incorporate space for trees, play areas, intensive landscaping like biophilic green walls and roofs and even intensive food gardens with water collection and recycling, are for some reason not acceptable.
Myth 6: High density housing consumes more energy and produces more greenhouse gas
The recent arguments against high-rise housing are suggesting that these building types are dangerous to the future of the planet as they consume more energy and produce more greenhouse gases than single detached low density housing. This is not true based on first principles of architectural design and in the scientific evaluations that are happening.
The argument depends on high-rise housing having large energy consuming areas like public lift spaces, public parking and public common areas for spas and swimming pools. The data used to support this invariably include buildings with the high energy consuming areas (mostly very wealthy) compared to the whole low density housing stock that mostly do not have such facilities as spas and swimming pools. This is wrong scientifically.
The history of architecture shows that one of the key reasons for compact houses was to share walls to conserve energy for heating and cooling. Thus, most evidence comparing high and low density housing (using similar wealth levels) shows that high density consumes less energy as heating and cooling are the biggest factors.
The biggest difference between housing types is in their associated transport energy. Here the main factor is location and in Australian cities this is easily measured by how far from the CBD the housing is. Central/inner denser housing is between four and 10 times less transport energy consuming than low density outer/fringe suburbs.
High density housing is attracted to areas closer in and hence mostly high density housing is not only lower in its building energy, it is much lower in its transport energy. As fuel and electricity prices rise this energy factor will continue to be a major reason why high-rise housing will be needed in increasing amounts, especially if well located.
Myth 7: High density housing is not necessary as renewable energy and electric vehicles will mean we can drive as much as we like
This is also a new argument by those who concede that high density can indeed save energy, but perhaps they say this will not be needed as renewables and electric vehicles will mean we can have fossil fuel-free cities and low density.
Even with renewables and electric vehicles in our cities they are still car dependent with rapidly growing suburbs. By 2050 when the world needs to have removed 80 per cent of fossil fuels, there will still be huge areas of American and Australian cities with low density car-dependent suburbs.
To be truly sustainable, these areas will need to have totally converted to renewables and electric vehicles.
There is a bigger problem: traffic. Automobile dependent city roads are already full. It is not sensible to imagine traffic increase based on electric vehicles rather than reducing the need to use a car. This will happen if high density well-located housing redevelopment is provided around rail stations and inner/middle suburban areas with good access.
Future cities will need renewables, electric vehicles and transit-oriented high-rise – as fast as possible.
Myth 8: High density housing development is destroying the heritage buildings of our suburbs
In every era of urban development there are buildings we want to keep as they are beautiful, full of history and with sensitive restoration they can be given a new life. Most cities conserve their heritage as a part of their redevelopment. However, most urban redevelopment is in newly created spaces based on redundant industries or warehouses and considerable opportunities exist for adding new houses into under-utilised urban space.
The most creative cities can do restoration and redevelopment that enables a city’s economic and social life to grow. Perth’s inner areas are mostly good examples of redevelopment and Fremantle has almost doubled its housing stock while restoring its heritage.
The biggest issue facing American and Australian cities is the lack of creative higher density opportunities being enabled in other than the old brownfield sites. There are many more opportunities for redevelopment in inner and middle suburbs but most housing redevelopment is either simple, dysfunctional low density infill of backyards or very wealthy high-rise. Car-based cities need to hold on to their quality heritage but add considerably more affordable high-rise housing in inner and middle suburbs. Heritage housing restoration and high density redevelopment are not incompatible – they are both needed.
Myth 9: High density housing redevelopment is wasting the materials and embedded energy in suburban housing
When housing life is near its end the question becomes whether it should be redeveloped as part of high-rise housing or restored as a low density heritage house. The extra argument that is now being presented to stop the high-rise option is that the planet will benefit from not wasting the materials and embedded energy in a house.
The answer is that any building’s materials can be recycled and thus, save most of its embedded energy. There are many ways of reusing building materials. Even a timber and asbestos house can be redeveloped; in one example, a building was recycled as a prefab home after the asbestos was removed.
New high-rise housing can use much lower embedded energy and low-carbon/low cost wall and roof materials, especially if constructed by off-site manufacturing and simply joined together on site. An assessment of the reductions in embedded energy, basic raw materials and waste saved in Perth shows the huge potential for savings in basic raw materials with redevelopment using OSM, compared to business as usual urban development on the fringe (15 tonnes using OSM compared to the 288 tonnes per person for BAU).
High-rise housing is a major part of the planetary resource solution, not part of the problem.
Myth 10: High density housing is not good for the economy
A range of markets drives the economy and it is true that much of the housing market in automobile dependent cities has become oriented to the low density project house market on the urban fringe. However, the new high density housing market is rapidly growing and many firms are adapting to these new opportunities.
In terms of the economy there are many benefits in this high-rise market compared to the low density urban fringe market:
Urban fringe housing is subsidised by state and local governments. In Australia this is around $100,000 per dwelling. Similar data are found in American cities. In Perth this means $45.4 billion in the next 30 years unless redevelopment happens on appropriate sites in inner and middle suburbs.
Urban fringe housing costs the economy hugely in extra transport costs due to the extra car travel. In Australian cities each dwelling built on the fringe involves an additional $250,000 over the lifetime of the house in travel cost. In the next 30 years this will cost Perth $133.6 billion just in time lost to travelling. Denser cities have 5-8 per cent of their GDP spent on transport; low density cities have 12-15 per cent of their GDP spent on transport.
Walkable high density areas have improved health due to greater walkability and improved productivity outcomes due to greater attentiveness and less days lost.
Much more of the revenue from its residents is spent locally on personal services such as restaurants, childcare and entertainment rather than on cars and housing DIY which invariably go out of the local economy.
High density housing will improve the economy of any low density city. In Perth this would amount to $212.9 billion of savings over the next 30 years of urban development.
Professor Peter Newman is an environmental scientist, author and educator based in Perth, Western Australia. He is currently Professor of Sustainability at Curtin University and director of the Curtin University Sustainability Policy Institute.