Cities and towns are places where people live that have implications beyond the qualities of individual houses, schools and workplaces.  As land becomes more intensively used and scarce, as cities and towns become larger and more densely populated, the impacts of cities and towns upon liveability and affordability for residents becomes more pronounced.  

The affordability of housing and other services is becoming more challenging as the proportion of income required to secure housing for low and middle income persons becomes greater over time.  Further, the distribution of poorer and richer persons is becoming more polarised in many cities and towns – where the rich are wealthier, and the poor worse off - and these groups often live in different parts of cities.  The provision and fair distribution in a city of affordable, quality housing, and services such as schools, health and child care to a broad range of the population continues to be an ongoing challenge, even in developed countries.  The ability to provide these has implications for the social and economic sustainability of places over time.  

Cities and towns also need to provide the benefits of liveability in the ways that everyday life is sustained.  Is daily life pleasant and stimulating, can people travel to and from work in ways that are convenient, safe and stress free, or can a range of options for entertainment be found near places of work, education and homes?  As cities and towns are used more intensively, these challenges are increasingly more complex and require innovative and integrated responses.