The Retrofit Housing Atlas: Adaptive reuse of housing in Australia

What we are doing and why

The Building and Plumbing Commission (BPC) supported research by Monash University through the Building 4.0 Cooperative Research Centre, to examine whether Australia’s existing housing stock could play a larger role in meeting future housing and climate objectives through retrofit rather than demolition and redevelopment.

Australia is facing a converging set of housing and climate challenges: the need to deliver more homes, support more diverse households, create greener neighbourhoods and reduce the carbon impacts of construction. At the same time, much of Australia’s suburban housing stock remains an underutilised resource despite its potential to contribute to these challenges through adaptation and reuse.

The research proposes that common housing types should not be understood as outdated or expendable. It argues that Australia’s existing housing stock should be viewed as a significant national asset, capable of contributing to increased housing supply, housing diversity, climate resilience and emissions reduction if adapted strategically rather than demolished and replaced.

The project developed the Retrofit Housing Catalogue, a national catalogue of 35 representative housing types drawn from eight Australian capital cities: Adelaide, Brisbane, Canberra, Darwin, Hobart, Melbourne, Perth and Sydney. It identifies four to five common housing types in each city, reflecting the evolution of Australian housing from the 1940s through to the 2000s, and groups them into nine common typologies: cottages, bungalows, walk-up flats, villas, villa clusters, mansions, townhouses, garage houses and regionally specific housing forms. Through representative case studies and spatial mapping, the catalogue documents the characteristics, distribution and prevalence of these housing types, providing the first national evidence base on the scale of Australia's retrofit opportunity and identifying opportunities for standardised retrofit solutions.

The research combined typological analysis, architectural documentation, GIS mapping, design testing and industry engagement, drawing on the expertise of housing specialists from across Australia.

The project was led by Monash University’s Associate Professor Maryam Gusheh. It was undertaken under Building 4.0’s Special Interest Projects (SIP) Program. SIPs have a topic of broad, mutual concern to all Building 4.0 partners and allow for collaboration and accelerated execution of the projects. The research report was published in 2026.

What we found

The research identified more than 330,000 examples of common housing types across Australia's capital cities with potential for systematic retrofit and greening interventions. Collectively, these housing types demonstrate the scale of the opportunity to increase housing supply and diversity while improving environmental outcomes and urban greening.

The catalogue proposes a series of small, strategic retrofit and greening actions that could be applied across common housing types to support housing density, housing diversity and urban greening. The actions were designed to align with modular construction and modern methods of construction, creating opportunities for more repeatable and scalable retrofit solutions. The research developed and modelled three broad retrofit strategies:

• Modular additions, including secondary dwellings, garage studios and additional storeys to existing apartment buildings or sites.
• Soft subdivision, allowing larger dwellings to accommodate multiple households while remaining within the existing building envelope.
• Greening interventions, including increased tree canopy, reduced hard surfaces and more permeable landscapes.

Under a hypothetical scenario of full uptake, these retrofit approaches could generate:

• Around 540,000 additional homes or equivalent dwelling opportunities across Australia.
• Significant increases in housing diversity, including housing options that support ageing in place, co-living, multi-generational households, hybrid work, and more affordable, smaller-footprint living.
• Up to 4.45 million square metres of additional tree canopy across participating cities.

While these scenarios assume full uptake and are intended to be indicative rather than prescriptive, the report notes that even partial adoption could make a meaningful contribution to Australia’s housing supply targets while supporting climate and urban greening objectives.

What difference this makes

The project has produced Australia's first national catalogue of common housing types focused on retrofit potential. By documenting the characteristics, distribution and quantity of common housing types and testing retrofit interventions across them, the research provides the first national evidence base on the scale of Australia’s retrofit opportunity.

The findings demonstrate how common housing retrofit could increase housing choice, support additional housing supply and contribute to urban greening while reducing demolition and lowering embodied carbon. The research also identifies opportunities for new skills, markets and housing delivery pathways through more systematic approaches to retrofit.

The research demonstrates that retrofit can complement new housing supply by providing a scalable pathway to increase housing density and urban greening within established suburbs, while retaining existing buildings and neighbourhood character. By adapting existing homes rather than demolishing and rebuilding them, retrofit can reduce construction waste, protect mature vegetation and help communities remain connected to established neighbourhoods. It can also support ageing in place, multi-generational living and other housing arrangements that allow people to remain within their communities as their needs change.

The project also identified opportunities to support national housing objectives. Under a hypothetical full-adoption scenario, retrofit of common housing types could generate around 540,000 additional homes or equivalent dwelling opportunities. Even partial uptake could make a meaningful contribution toward the National Housing Accord target of 1.2 million new homes if supported through appropriate policy, regulation and market settings.

Industry partners identified several barriers to retrofit uptake, including regulatory complexity, workforce capability, access to property data, commercial feasibility and consumer demand. The research also highlights opportunities to move retrofit beyond one-off renovation projects through standardised retrofit designs, modular components and modern methods of construction that could be applied across large numbers of similar dwellings.

The report recommends further work in three priority areas:

• Regulatory retrofit framework: Development of a dedicated framework to support and incentivise retrofit, including risk-based compliance pathways and guidance for common building types.
• Retrofit education and training: Creation of specialised training, apprenticeship pathways and professional development programs to build industry capability in retrofit delivery, modern methods of construction and building performance.
• Retrofit feasibility tools: Development of practical decision-making tools that assess costs, benefits, compliance requirements, carbon impacts and commercial viability across different housing types and jurisdictions.

Full report

Read the full report: Retrofit Housing Catalogue – Systematic densification, diversification and greening of Australian common housing types