ing such housing environmentally sound and the high price of inner-city land. Building more storeys on the lot (e.g. 6 storeys instead of 2 storeys) will help reduce land costs per unit.
The most recent National Housing Supply Council annual report reveals that the gap between demand and supply in Australian cities in 2011 increased by over 28,000 units, to almost 200,000 units [22,23]. This report also notes an acute undersupply of inner-city housing within existing urban (brownfield) areas for low-income earners. What is missing is choice of an urban lifestyle where residents can walk to work or restaurants, which systematically restores health through walking or cycling, while reducing carbon emissions and air pollution.
To achieve the required industry and market transformation we need to develop low carbon systems with elements and components for rapid assembly of buildings, while ensuring user acceptance. This is the topic of the ongoing research project introduced in this article.
1.2. An Ongoing Research Project that Studies Two Main Issues
The aim of the ongoing research, stemming from the described practical gap in infill housing, is to study two problems: firstly, to develop better models of urban infill housing. Then to focus on how the use of cross-laminated timber systems could play an important role in achieving a more livable city through facilitating better models of infill. Results will also be obtained from the in-depth analysis of eight built cases that have recently been constructed using CLT systems.
Modular cross-laminated timber (CLT, also called cross-lam) panels form the basis of low-carbon, engineered construction systems using solid wood panels that can be used to build residential infill developments of 10 storeys or higher. These prefabricated engineered solid wood panel construction systems sequester and store CO2 (timber acts as a carbon sink through conversion of CO2 to biomass in the process of bio-sequestration via photosynthesis). A part of the research project will explore the lifestyle changes more and more Australians are choosing: to move from living in the suburbs to the city centre. There is still a knowledge gap about existing cultural barriers and perceptions of infill timber buildings, and a need to better understand the social acceptance of multi-storey solid wood panel construction (such as CLT) for urban infill apartment living. There is a need for greater densification of our cities and CLT provides an opportunity to address the problem: ‘brownfield’ and ‘greyfield’ infill as affordable but attractive medium density housing stock, answering the particular problem of housing shortage and a resistance to ‘chicken coops’ (most apartment buildings in Australian cities are tall, made of concrete and are not based on needs, offering poor value compared to suburban homes).
Timber is the world’s oldest construction material, and has unrivalled carbon credentials. Around 1995, the new engineered timber systems emerged in the well-forested sub-Alpine regions of Germany, Austria and Switzerland. Introducing CLT construction systems to Australian cities would mean: rethinking design and construction standards, a renewed focus on modular prefabricated construction systems via digital design tools; but also a focus on material culture and a different understanding of residential development practice in general. The shift to resource-optimized urban infill buildings constructed with engineered timber systems will require behaviour change, to ensure these buildings will be fully acceptable to their occupants.
Why is wood still perceived as a risky option, compared to the usual concrete and steel? Usually fire, insects and acoustics are named as the risks and reason for prejudice. But in order for prefabricated engineered solid wood panel systems to be effective in Australia, consumer acceptance, availability of resource, knowledge transfer for appropriate design, local fabrication and construction capacity must all be aligned. Otherwise, CLT timber systems will not be feasible due to rela