Maya de Souza draws on her experience of living in Hong Kong to argue in favour of high-rise, high density cities. While acknowledging that this form of development can have its downsides, when well-designed, it can have substantial advantages over less dense forms of development: it makes public transport viable; frees up land for food growing, water, nature and recreation, and reduces the amount of land that needs to be protected from floods and coastal storm surges. They can also be good places to live.
De Souza's proposition is that this approach to city design is an important part of a strategy for those countries in the process of mass urbanisation, but even countries with well-established cities should consider this approach. In facing up to climate reality we need to consider design of this nature with an open mind. The low-rise medium density development option often preferred by the environmentalist has major downsides.
De Souza aim is to explore an approach which achieves multiple objectives, essentially finding a way of living within the parameters we face whilst also ensuring well-being. This is in effect the goal of sustainable development, neatly encapsulated more recently in Kate Raworth’s Doughnut Economics model.
The parameters are the need to reduce GHG emissions from infrastructure construction, transport, cooling and heating buildings, noting a rising population and urbanisation, whilst also providing for rising living standards and well-being. That means a need to find space for farmland and market gardens, protecting biodiversity from encroachment, and providing sites for leisure activities. It’s also necessary to ensure there is space for water when it floods, which can otherwise wreak havoc, as we have seen in cities from Beira to Chennai. These parameters affect the sort of city we can afford to build.
With reference to the Hong Kong model of design and urban planning, de Souza seeks to show that high-rise, high density living if done well is a good way to manage within the parameters we face. Illustrating this with examples, she shows how high-rise high-density living can be appealing, taking on board the possibilities in terms of shared community space and roof gardens, as well as ease of access to public transport. One of the high-density developments we lived in had a bus stop underneath it. Within half an hour, one could drive over the hills and through the forests of Hong Kong Island to arrive at Stanley Beach, the equivalent of London’s Brighton or Margate.
So shifting away from the tourist brochure, what are the overall advantages of this style of development? Several, including: affordable mass transport which reduces time and pollution, combined with the potential to reduce other infrastructure costs, plus the protection of local farmland, enhancement of leisure space and making nature – beaches or hill walks in the case of Hong Kong, accessible by avoiding traffic and urban sprawl.
Are there any downsides? It is fair to say that there are, but de Souza's contention is that they can be addressed. Some studies suggest that energy usage and the heat island effect can increase, however these problems can be mitigated by good design. It is accepted that without some security of supply very tall buildings are not manageable. Embodied carbon is another issue: construction materials can be highly carbon intensive. However new materials such as cross-laminated wood make it easier to build in hybrid form. Tall buildings using this are being designed and built every year.
Other arguments that are put against high-rise, high density are far from compelling. For example, supply chains and logistics can be an issue – but this is less of an issue in high density cities which do not have roads clogged up with traffic. And that is one of the benefits of this approach: there is less need for private cars. Another is heritage and identity plus crime and community, and benefits of wellbeing from nature. These issues do need to be taken on board, but solutions can be found.
De Souza suggest that active blueprint planning is vital to make this happen, as the benefits are only fully obtained through an integrated approach to planning. A lot of planning theory has focused on the normative, but we do need to explore positive theories. There is a need for blueprint planning - in particular an integrated approach to transport, housing, leisure and access to nature, if we are to meet the goals of maximising well-being within the parameters we are faced with.