M Dewsbury

The Unintended Consequence of Building Sustainably in Australia

What makes a sustainable house? One might suggest it should be energy-efficient, resilient to climate change and still comfortable. Indeed in Australia, we see aspects of these three priorities being exercised: energy-efficiency standards being introduced into residential requirements of the National Construction Code in 2003, bushfire requirements expressed as a national standard in 2009, and the constant demand for more efficient and round-the-clock climate control. All these actions relate to Sustainable Development Goal (SDG) 13: Climate Action. One might assume that these trends mark progress for both the environment and the home owners. However there is a dark side to the story, because in the very effort of reducing greenhouse gas emissions (also one of the functional objective of the national construction code), the construction industry has inadvertently implemented practices that have led to entrapment of moisture in buildings, thus compromising their habitability. Using data from Tasmania, this chapter shows how common mistakes in building science, design and construction have led to a widespread increase of condensation in buildings located in cool climates. Condensation has further led to other problems with mould and health (SDG 3: Good Health and Well-being), making new code-compliant houses potentially uninhabitable after experiencing their first winter. These challenges need to be in the wider discussion of architecture, construction, indoor microbiology and public health when sustainable housing standards are being promoted.

Results, Analysis and Discussion of Empirical Validation

This chapter presents and discusses selected data that were collected and analysed in graphical form.

Background to Australian House Energy Rating

This chapter discusses the context of space heating and its associated energy use in Australian residential buildings. The use of heating is then considered in the context of Australian greenhouse gas emissions and the recent acceptance of the need to stabilise and then reduce emissions. To achieve a reduction in residential greenhouse gas emissions, a range of measures have been developed by industry and government. One of these measures to reduce the energy for heating and cooling due to poor building envelope designs was to introduce residential house energy star-ratings for new Australian housing (Delsante 1996). A number of industry groups raised concerns with regard to the effectiveness and capabilities of the HER star-rating softwares. These are discussed in Chap. 2 and Chap. 3 then discusses the history and complexities of house energy rating software validation.

Background to HER Program Validation

The previous chapter discussed our natural desire to make spaces, and especially our houses, thermally comfortable. As houses have become bigger and personal wealth has increased, the amount of energy consumed to create comfort has increased (Harvey 2006). In recent years the anthropogenic creation and use of energy, including that to condition houses, has been linked to climate change. In response to the threat of climate change, many governments have instigated methods to reduce the production of greenhouse gases, which have included thermal performance targets for new and existing housing. This has led to the adoption of detailed thermal simulation programs to evaluate the possible thermal performance of a particular house in a given climate. In response to these new government regulations, many building industry and related groups have raised concern as to the capacity and validity of the house energy rating softwares adopted within Australia to predict room temperatures. These groups have requested the software be validated, modified and calibrated, to give the Australian community confidence in and acceptance of the house energy rating softwares (Dewsbury et al. 2007).