Heritage advocates working to protect local areas have often been accused of adopting a backward looking approach that is out of step with the needs of buildings to be more sustainable. However, heritage professionals and organisations are working to bridge this divide. This article explores three different approaches that show another side of heritage practices and one that is decidedly forward looking.
The cultural heritage framework in Australia is based on the idea of heritage value. If a place is assessed as having heritage value then it is worth keeping for future generations. Similarly, the concept of sustainability is also a value system that is becoming embedded in our culture.
What constitutes environmental sustainability is ultimately a social and political question as much as a scientific one. In fact, moving towards an environmentally sustainable Australia will depend not only on our knowledge of ecosystems and resources but even more on our ability to initiate, advocate and absorb radical shifts in desired lifestyles, values and technology.¹
There are challenges in this for society as a whole. The challenge has been taken up by heritage organisations in several ways including research, advocacy and demonstration projects. The key areas where environmental sustainability is linked with heritage conservation include the environmental performance of buildings, the applicability of rating tools and the opportunities to learn about sustainable living practices from our past.
Heritage and environmental sustainability
The Heritage Council of Victoria has recently undertaken a heritage and sustainability project based on research into different domestic building typologies across different climatic zones. This research project was undertaken with support and funding from the Building Commission (predecessor to the Victorian Building Authority) and various Victorian government bodies.²
The study was instigated after the introduction of Section J into the Building Code of Australia to regulate minimum energy efficiency standards for building fabric and services. At this time, heritage advocates feared that Section J might mandate unsympathetic interventions for heritage buildings. The project aimed to develop a greater understanding of the existing embodied energy in ‘typical’ residential buildings, to enable an assessment of the potential environmental implications and outcomes of retaining the built fabric. Costs and benefits of common interventions to improve the environmental performance were assessed.
Advanced energy modelling software was used in place of the more basic residential energy rating tools that were commonly in use at the time. Case studies, that are now publicly available online, were selected from Queensland, South Australia, Victoria and New South Wales.
In 2009 a similar research project was undertaken for non-residential buildings. Subsequently the Environment Protection and Heritage Ministerial Council adopted these two Heritage and Sustainability projects as part of the Co-operative National Heritage Agenda.
The residential project demonstrated a range of practical improvements relating to the building thermal envelope, glazing, and ventilation that could be made to enhance environmental performance. When life cycle analysis was factored in, existing houses rated relatively highly when compared with most new houses. In contrast to this, improvements in the performance of non-residential buildings were largely attributable to the addition of newer and more energy efficient active heating, cooling, ventilation and lighting systems.
Improving rating tools
The environmental benefits of retaining existing buildings, whether heritage or not, may be discounted through existing rating tools that fail to include embodied energy, life cycle analysis and waste in their calculations. The US rating tool, LEED discriminates against refurbishment projects. Renewed certification is required every five years for refurbishments but not for new construction. It is assumed that the new building will remain efficient just because it was originally designed to be so.³
The Green Building Council of Australia (GBCA) Green Star rating tool does not give adequate credit for the retention of existing buildings. It gives more ‘green’ points on its scorecard for the use of recycled materials than for whole recycled buildings. If rating tools were expanded to consider the full benefits of retention and adaptation of existing buildings, better information would be available to inform design decisions.
However, there is one excellent example of the commercial green star rating system used to good effect in the refurbishment of the Perpetual building at 39 Hunter Street, Sydney by Jackson Teece Partnership. This was the first heritage building in Australia to achieve a six star Green Star rating, following extensive refurbishment works. Existing features have been retained including vaulted ceilings and decorative columns and beams. Innovative sustainable services upgrades complement the restoration work.
In order to create a level playing field green rating tools require greater flexibility to respond to varied project types including new buildings, holistic adaptive re-use and partial retention projects. Inclusion of criteria to assess the relative impacts of existing embodied energy against waste production from demolition, could assist in the environmental impact assessment and decision-making process for clients and design teams during the early phase of a project.
Learning from heritage places
The current Queensland Heritage Strategy links heritage with sustainability through the idea that heritage places can become demonstration projects providing a resource from which we can learn about past approaches to living in a low-energy economy.⁴
Heritage organisations are keen to show leadership in this area. At the Sydney Living Museums’ Rouse Hill house in Western Sydney, the whole property has been presented to the public as a centre focusing on contemporary urban environmental issues. Sydney, like other places, faces problems of excessive water and energy consumption, poor building design, endangered vegetation, and rapid urban growth. The heritage-listed Rouse Hill house and farm demonstrates positive action, educating visitors about recycling of materials, water retention and land management.
Similarly in Melbourne, the National Trust at Rippon Lea Estate has re-developed the extensive garden using water-wise principles; restoring the nineteenth century drainage system, reservoir and lake to store and circulate water for the property. In addition, the recent restoration of the terracotta tile roof included the installation of a photovoltaic array.
Sustainable building requires holistic consideration of the impact of the project, whether it is conserving heritage places or designing new sustainable buildings. In this process heritage can be a partner in achieving sustainability. Through establishing the environmental performance of existing buildings and their scope for improvement, the value of retention or demolition may be more considered.
This approach might then be supported by the use of rating tools that offer a more comprehensive approach to the recycling of whole buildings, giving credit for waste reduction and the retention of embodied energy. Finally the continued involvement of heritage organisations to demonstrate sustainable initiatives from our past can provide useful role models for others to follow in the future.
Louise Honman is an architect and Director of Context Pty Ltd – a multi-disciplinary heritage consultancy. She combines work in the cultural heritage field with a strong interest in the social, economic and environmental sustainability of buildings.
1. McKenzie, S. 2004, Social Sustainability, Towards Some Definitions, Hawke Research Institute SA, Working Paper Series no.27, p10
2. Heritage Victoria : http://www.dpcd.vic.gov.au/heritage/projects-and-programs/heritage-places-and-sustainability
3. Fielder,K., Keeping it Green, Construction Week online, 17.9.2013 http://www.constructionweekonline.com/article-24171-keeping-it-green/#.UsjoNPbeklX
4. Department of Environment and Heritage Protection, Queensland http://www.ehp.qld.gov.au/heritage/pdf/heritage-strategy-ten-year-plan.pdf