This research, commenced at July 2009, explores the process of reinvestment in lower density housing which has become a significant factor in the incremental renewal of these areas with implications for their socio-economic stability as well as their adaptation to improved environmental standards. Using both quantitative and qualitative research methods and Sydney as an exemplar, the project studies the rate and scale of renewal and the drivers of this process from both the supply and demand side of the market.

The objectives of the project are to:

• Identify the drivers of demand and supply for knockdown-rebuild and major renovations (henceforth ‘KDR&R’) activity in the housing market in the middle-ring suburbs of lower socio-economic status in Sydney.
• Identify the role of the KDR&R market in contributing to urban economic sustainability in these middle suburbs and to identify those factors that differentiate the Australian case from the decline experienced in equivalent suburbs (the so-called ‘First Suburbs’) in many US cities and elsewhere.
• Identify the influence of KDR&R in relation to social stability, including retaining population and supporting social investment and social cohesion.
• Examine the utility of KDR&R in re-fitting existing suburbs to enable improved environmental standards.

Based primarily on analysis of Development Applications at local councils and census data, much data has already been collected to inform an assessment of the magnitude and the geography of knockdown-rebuild and major renovations activity in Sydney, and its correlation with various socio-economic and land value factors. The major findings include:

• Over 7000 instances of knockdown-rebuild were identified in 30 Local Government Areas (LGAs) in Sydney’s metropolitan area since 2004.
• Level of knockdown-rebuild activity varies between regions. In most regions between 1% and 2.5% of the total stock of detached houses has been knocked down and rebuilt in the last 5 years.
• A more detailed, Intra-regional ABS Collector District (CD) level analysis of relationship between knockdown-rebuild activity and various socio-economic dynamics identified four distinct sub-markets of knockdown-rebuild. Two of these submarkets include areas with high presence of immigrants.

The next phases of the project will include a survey to the entire sample of properties in which knockdown-rebuild has taken place in the last 5 years, and over 80 in-depth face-to-face interviews with residents, planners and builders in the knockdown-rebuild industry.

List of publications

• Legacy, C. and Wiesel, I. (2012) Knockdown-rebuild: Where is it on the planning agenda? 6th Australasian Housing Researchers Conference, 8-10 February 2012, Adelaide
• Pinnegar, S., Freestone, R. and Randolph, B. (2010) Suburban reinvestment through knockdown rebuild in Sydney, in M. Clapson and R. Hutchison (Eds) Suburbanisation in Urban Sociology, Volume 10, 205-229
• Pinnegar, S., Freestone, R. and Randolph, B. and Vizel, I. (2010), Suburban reinvestment through knockdown rebuild in Sydney ENHR, 4-7 July 2010, Istanbul
• Randolph, B. and Freestone, R. (2012) Housing differentiation and renewal in middle-ring suburbs: The experience of Sydney, Australia, Urban Studies
• Tice, A., Pinnegar, S., Wiesel, I. (2011) Knockdown-rebuild in Sydney: addressing household and place in a study of residential choice and local change, State Of Australian Cities Conference, November 2011, Melbourne
• Wiesel, I., Freestone, R., Pinnegar, S., Randolph, B. (2011). Gen-X-trification: The replacement of housing and residents in ageing neighbourhoods, State Of Australian Cities Conference, November 2011, Melbourne
• Wiesel, I., Freestone, R., Pinnegar, S., Randolph, B., Tice, A. (2011), Knockdown-Rebuild: Drivers of reinvestment in low-density suburban housing, World Planning School Conference, Perth, 5-7 July 2011