Towards Net Zero Energy for Older Apartment Buildings in Brisbane

Towards Net Zero Energy for Older Apartment Buildings in Brisbane

Authors:

Paul Matthew and Paola Leardini

Organisation of Presenter:

University of Queensland, Australia

Abstract:

Between 1961 and 1981 the number of Australian apartments and flats more than tripled in response to booming post WW2 immigration, growing local manufacturing industries and the new construction skills of migrants. The Australian Bureau of Statistics records that more than 500,000 brick flats and apartments dwellings were built in this period.

This apartment building cohort is very consistent in construction method, with cavity brickwork external walls, rendered brick internal walls and concrete slab floors that form the ceiling of the apartment below. Roofs are typically an uninsulated low pitch metal sheet with fibre cement (or asbestos) ceilings and soffits below. These buildings were built in an age where there were no energy or water efficiency regulations and, although some have had internal renovations, many remain close to original condition.

They are now around 40 years old and are facing the need for replacement of substantial parts of their building envelopes; roof sheeting, doors, windows, balustrades and lifts are reaching the end of their serviceable life as are some energy intensive services such as hot water systems and stovetops. The uniformity of this building type and the number of dwellings involved makes it worth investigating what renovation strategies could be implemented to improve their energy efficiency and indoor comfort conditions. International examples show that substantial energy demand reduction is possible and net zero energy is an achievable and cost effective target for some of these apartment blocks.

This paper presents initial results of ongoing research into the current condition and future value of 1960s and 1970s apartment buildings in Brisbane, aiming to identify renovation measures that prove suitable for the specific climatic and socio-economic context.

Modelling tools are employed to assess hygro-thermal behaviour and energy consumption of a typical building, comparing its current and post energy retrofit performance. The feasibility of the most effective retrofit strategies is then evaluated in light of socio economic factors, and conclusions are drawn about the best future for these buildings and their inhabitants, as well as the decisions required to achieve it.