Retrofitting Melbourne’s high-rise social housing buildings: improving liveability and energy performance in a circular economy
Architectural Engineering Thesis Semester 2, 2023
Retrofitting Melbourne’s high-rise social housing buildings: improving liveability and energy performance in a circular economy
45 social housing high-rise buildings (of more than eight stories) were constructed across 21 estates in Melbourne (see Figure 1) by The Housing Commission of Victoria over a 15 year period from 1960 to 1975, comprising 7,834 apartment units ranging from 27 sqm bedsitters to 96 sqm 3-bedroom apartment units (Vella, 1990). The buildings are predominantly located in the inner city (McNeils & Reynolds, 2001) and were assembled in-situ using a precast concrete panel system of floors and walls (see Figure 2) of different thicknesses (due to structural considerations) (Vella, 1990). Today, these buildings account for 10 per cent of Melbourne’s social housing stock (Jara-Baeza, Rajagopalan & Andamon, 2023) and have significant social history and embodied carbon.
Melbourne’s high-rise social housing towers account for 10 per cent of the city’s social housing stock.
(Jara-Baeza, Rajagopalan & Andamon, 2023)
The high-rise social housing buildings were constructed in response to the slum reclamation plan released in 1955 by the then Premier of Victoria, Henry Bolte, aimed at eradicating the “bad houses in Melbourne’s inner city because … bad houses made bad people’’ (Vella, 1990). This thinking had been around since the 1930s (see Figure 3). In the 1950s and 1960s, The Housing Commission of Victoria launched several ambitious slum-clearance projects (Matthews, 2015) that received backlash from affected communities who did not want to move (see Figure 4). Individual rights and well-being were being sidelined for ‘greater public good’. The result was social dislocation on a massive scale whereby “family and friendship networks were demolished and a way of life effectively destroyed” (Vella, 1990).
...bad houses made bad people. (Vella, 1990)
Who do they house?
Social housing provides homes for some of our most vulnerable populations (low-income, elderly, sick) (see Figure 5) (Jara-Baeza, Rajagopalan & Andamon, 2023). Today, Melbourne’s social housing high-rise buildings provide access to inner city housing for low-income households that would otherwise be inaccessible due to increasingly high housing prices (McNeils & Reynolds, 2001). They also provide homes for culturally and ethnically diverse communities, including recently arrive migrants and refugee groups, that contribute to enriched local neighbourhoods (McNeils & Reynolds, 2001). Many residents have lived in the buildings for several years and have strong ties to their local communities (McGarry & OFFICE, 2023).
Figure 6. Margaret Kelly (right), with friend and supporter Lyn Dixon, says she won’t leave her home (Taylor, ca. 2023). Accessed, https://www.theage.com.au/politics/victoria/they-llhave-to-carry-me-out-inside-the-public-housing-estate-set-for-demolition-20230316-p5csoj. html.
Victoria’s current approach to social housing estate renewal is “a costly process of demolition, relocation and construction of new buildings” (McGarry & OFFICE, 2023). Within this model, the future of Melbourne’s social housing high-rise buildings is uncertain. Again, as happened in Melbourne during the 1950s and 1960s, there is a risk of significant social upheaval with residents expressing concerns of breaking their community ties “having to leave the proximity of work, schools, doctors, and other networks of support and care” (McGarry & OFFICE, 2023). A similar social housing estate renewal program conducted in Kensington during the late 1990s and early 2000s resulted in only 20 percent of residents returning to the newly built dwellings (Shaw, 2012) despite the theoretical ‘right to return’.
Figure 7. Media releases for Victoria’s Housing Statement. Images accessed, (left) https://www.theage.com.au/politics/victoria/plan-to-demolish-rebuild-public-housingtowers-savaged-by-urban-experts-20230921-p5e6hz.html and (right) https://www.abc. net.au/news/2023-09-21/residents-shocked-by-plan-to-rebuild-melbourne-public-housing/102883398
On 20 September 2023, the Victorian Government announced a significant urban renewal project called Victoria’s Housing Statement. Melbourne’s 44 high-rise social housing buildings will be demolished and replaced with a mixture of private and social housing between 2023 and 2051, resulting in the forcible relocation of approximately 10,000 residents (Victorian Government, 2023). Currently, there is no publicly available information that supports the government’s assertion that the buildings are derelict beyond the point of retrofit, and no potential retrofit alternatives have been proposed (Porter et al., 2023).
In the context of a circular economy, Melbourne’s high-rise social housing buildings should be considered significant embodied carbon banks that should be preserved for their structurally feasible lives. No embodied carbon assessment has been conducted for the buildings to date. However, a Danish joint research project Ressource Blokken (2021) between industry partners, housing associations and research institutions conducted a Life Cycle Assessment (LCA) of a similar social housing typology (see Figure 8).
Birkeparken 65 is an eight story social housing building comprising 143 apartment units located in Vollsmose, Denmark. It was constructed using prefabricated concrete panels that were cast in-situ between 1970 and 1974 (Studio Housing: Research, 2022). Almost 2,000 tonnes of CO2 is embodied in the structure’s primary precast concrete elements (floors and walls) alone (Ressource Blokken, 2021). The building is approximately twice the total floor area of the T-shaped social housing high-rise building in Footscray. Hence, it is assumed that the embodied CO2 of the building’s primary precast concrete elements is approximately 1,000 tonnes. This is significant, considering there are 44 similar building typologies in Melbourne.
The buildings are currently 60 to 70 years old. In 1990, Vella wrote that Melbourne’s high-rise social housing buildings are structurally sound and “have a projected life well into the 21st century”. Various sources suggest the towers could last for another 60 (Barnett, 2023) to 85 years (Herald Sun, 2020), however there is no concrete evidence to back up these assumptions.
The indoor environmental quality (IEQ) of the single-sided units in Melbourne’s high-rise social housing buildings is mostly poor because of building design and characteristics, lack of maintenance and absence of appropriate heating, ventilating and air conditioning systems (Baeza, Rajagopalan & Andamon, 2020). This causes health, comfort, and wellbeing problems to a vulnerable population who spends around 95 percent of their time indoors. Human health, comfort, and well-being are defined separately according to Rohde et al. (2020) in the Indoor Environmental Quality (IEQ) literature:
Comfort = indoor conditions related to occupant’s satisfaction and annoyance avoidance based on preferences and the given activity performed (related to physical and psychological dimensions)
Health = attributed to indoor conditions which contribute to physical resilience, limiting conditions leading to infirmity, disease, and years of life lost (linked to physical and physiological dimensions)
Well-being = is associated with indoor environmental conditions which improve occupant’s happiness through the presence of positive stimuli, providing control and offering variations (associated with psychological dimension).
Poor quality housing and performance not only negatively affects tenants’ comfort, health, and well-being, it can also greatly affect living costs (Baker et al., 2023). Social housing typically has low energy consumption rates since they rely mostly on passive strategies due to the absence of mechanical systems (Jara Baeza, Rajagopalan & Andamon, 2023). However, where active systems are present their use is mostly limited to high associated operational energy costs, exacerbated by increasing energy prices (Jara Baeza, Rajagopalan & Andamon, 2023). Hence, vulnerability to energy poverty is a significant factor that affects social housing populations in Australia.
McNeils & Reynolds (2001) suggests a specific objective for regeneration of Melbourne’s high-rise social housing buildings is to ‘improve their amenity, in particular the social conditions’ within each building. One way to achieve this is to upgrade and redesign common areas. This can contribute to the tenants’ feelings of ownership and they can take pride in their homes. A strategy of reconfiguring dwelling sizes (i.e. number of bedrooms) over time to provide more flexibility in the context of the changing landscape of inner urban housing trends is also suggested. In doing so, the high-rise buildings can better meet the needs of diverse households seeking social housing in inner Melbourne.
Increasingly, circular economy (CE) principles (see Figure 10) are being adopted in the built environment. This has focused on reducing building’s environmental impact in the design, construction and end-of-life phases of buildings. Closing the loop between the extraction and use of resources and their subsequent disposal or reuse has been a key focus (Baker et al., 2023). Retrofitting is a key strategy that focuses on improving the quality and performance of dwellings during their operation phase, extending the life of existing dwellings. It opposes the demolition and redevelopment model which is commonly seen as the business as usual (BAU) approach which has significant environmental costs. If Melbourne’s existing high-rise social housing buildings can be retroffited at a reasonable price, this will have many environmental and social benefits.
The voice of tenants is rarely considered in discussions of social housing sustainable retrofits in the context of a circular economy (Baker et al., 2023). Liveability and affordability have been identified as priorities for tenants who are recipients of retrofit programs b(Baker et al., 2023). Many retrofit programs however focus on improving the performance of existing dwellings in terms of energy efficiency. It is important to consider the bottom-up approach when thinking about sustainable retrofitting social housing. Low-income renting households, especially those in the social housing sector, have been overlooked when it comes to retrofit programs in countries like Australia, where technological solutions aimed at higher socio-economic houses who can typically afford a sustainable retrofit have been the primary focus (Baker et al., 2023).
Figure 11. Cité du Grand Parc’ in Bordeaux photograph (top) and axonometric drawing (bottom). Images accessed, https://www.archdaily.com/915431/transformation-of-530-dwellings-lacaton-and-vassal-plus-frederic-druot-plus-christophe-hutin-architecture
Lacaton and Vassal’s approach of ‘Never demolish, never remove or replace, always add, transform, and reuse!’ is also evident in growing architecture, construction, design and urbanism sectors.
(ArchDaily, 2019)
12. Park Hill’s street-decks provide access to residences and provide space for children to play and operate small wheeled vehicles, functionally and socially acting as streets. Accessed at, https://twitter.com/brutalhouse/status/577254137643069440?lang=ga
Park Hill is Europe’s largest listed building located in Sheffield, UK. It was completed in 1961 and replaced overcrowded streets in the city with ‘streets in the sky’ (Waite, 2023). The estate fell into a state of disrepair due to poor mainenance and poor social status. Those who didn’t live their avoided it because of its status of antisocial behaviour, drugs and crime. In 1998 its future was uncertain and it was earmarked for demolition. ‘Fifty years after slum clearance, new slums stood again’ (Blundell-Jones, 2011). It was later sold to developer Urban Splash for redevelopment and to change the image of the delapedated estate. Redevelopment occurred in two phases. Phase one occurred in by Studio Egret West and Hawkins\ Brown. Phase two of the redevelopment was carried out by Mikhail
Park Hill is Europe’s largest listed building located in Sheffield, UK. It was completed in 1961 and replaced overcrowded streets in the city with ‘streets in the sky’ (Waite, 2023). The estate fell into a state of disrepair due to poor mainenance and poor social status. Those who didn’t live their avoided it because of its status of antisocial behaviour, drugs and crime. In 1998 its future was uncertain and it was earmarked for demolition. It was later sold to developer Urban Splash for redevelopment. Redevelopment occurred in three phases. Phase one occurred between December 2007 and April 2011 by Studio Egret West and Hawkins/Brown’s. Phase two of the redevelopment was carried out by Mikhail Riches. Phase three occurred between 2017 and 2020.
Phase one completely reimagined the estate. The transformation saw the building stripped back to its structural frame with new glazing and coloured powder-coated aluminium panels replacing the existing brick infill panels. This inverted the previous ratio between window and solid wall, significantly increasing the amount of glazing on the facade. This also significantly increased the thermal comfort of the building and radically changed the outwards facing image of the estate. Within the grid-like block structure, apartments were rearranged in new combinations.
Park Hill is Europe’s largest listed building located in Sheffield, UK. It was completed in 1961 and replaced overcrowded streets in the city with ‘streets in the sky’ (Waite, 2023). The estate fell into a state of disrepair due to poor mainenance and poor social status. Those who didn’t live their avoided it because of its status of antisocial behaviour, drugs and crime. In 1998 its future was uncertain and it was earmarked for demolition. It was later sold to developer Urban Splash for redevelopment. Redevelopment occurred in two phases. Phase one occurred in by Studio Egret West and Hawkins/Brown’s. Phase two of the redevelopment was carried out by Mikhail Riches
The literature review has revealed that social housing retrofits typically focus on technical improvements, such as energy performance, meaning that social impacts including liveability are overlooked. Hence, there is a need to balance technical and social retrofit aspirations to improve existing social housing buildings and the lives of those who live in them. To date in Melbourne no all-encompassing retrofit strategies have been proposed to improve the city’s existing high-rise social housing buildings. Furthermore, no in-depth energy performance or embodied carbon analysis of the buildings has been performed or published. The results of these analyses are essential to inform retrofit interventions aimed at improving energy performance by reducing energy demand in the context of a circular economy.
From the background study and literature review, a ‘façade subtract and add’ approach (see Figure 16) was found to have the most potential to improve both building performance and social outcomes. Additionally, the research calls for a socio-technical systems (STS) approach to projects that aim at improving building performance and social outcomes, such as energy performance and liveability. Circular economy principles such as prefabrication, material re-use, and the use of low embodied carbon materials for the retrofit should be considered, all whilst aiming to minimise disruption to residents.
There is a need to balance technical and social retrofit aspirations to improve existing social housing buildings, and the lives of those who live in them.
This thesis proposes a socio-technical systems (STS) approach to the retrofit of Melbourne’s high-rise social housing buildings, to improve liveability and energy performance in a circular economy.
The case study building is one of Melbourne’s existing high-rise social housing buildings, located within NatHERS Climate Zone 60 (Nationwide House Energy Rating Scheme, 2013) at 127 Gordon Street in Footscray, Melbourne. It is the only high-rise social housing building within the estate known as Gaskin Gardens (Vella, 1990). It is 13-storeys comprising 111 apartments of different configurations, including 89 x 1-bedroom apartments, 20 x bedsit apartments, and 2 x 2-bed apartments, across four different floor play typologies (see Appendix 3¬¬). The case study was selected based on the availability of documentation drawings and the shape of its plan.
Existing floor plan typologies
These figures illustrate each unique apartment across the 12 residential dwelling levels of 127 Gordon St Footscray. The corresponding percentage in the diagrams is the percentage of apartments in the building of that typology. Each apartment of that typology is also listed adjacent to the apartment. The information in these diagrams was used to select the apartments to be modelled using HERO (shown on the following pages).
Apartment typologies selected for energy demand models
The following apartments were selected for use in the HERO software energy demand modelling. Apartments with similar adjacencies were grouped together for model simplification.
C.8.4C.6.4C.4.4
D.12.5D.11.5D.10.5D.9.5D.7.5D.5.5
D.12.2D.11.2D.10.2D.9.2D.7.2D.5.2A.3.2A.1.2 B.2.2C.8.2C.6.2C.4.2
The following apartments were selected for use in the HERO software energy demand modelling. Apartments with similar adjacencies were grouped together for model simplification using a typological approach.
Different locations of the thermal buffer facade will result in the creation of different thermal zones. These different thermal zones have different impacts in terms of liveability and energy performance of the apartments.
Remove floor panel and place at lower level to make balcony and atrium space
Push forward / pull back thermal buffer to accommodate different spatial arrangments
Suspended planter boxes off frame to house deciduous vines
External stairs run height of building
Connection detail to existing structure
Retain cold rolled steel panels for re-use
Existing non-loadbearing typical corridor facade
Remove floor panel and place at lower level to make balcony and atrium space
Push forward / pull back thermal buffer to accommodate different spatial arrangments
Suspended planter boxes off frame to house deciduous vines on northern facade
External stairs run height of building providing an alternative way to access the building
