The Carbon Cost of Work—Impacts of Office Building and Commuting Energy in Sydney Workplaces

Abstract

We investigate greenhouse emissions of office workers in Sydney, drawing on census data, national building energy benchmarks as well as journey-to-work and energy data from two study buildings. Comparing work locations in the central business district (CBD) and Macquarie Park Corridor with metro-wide averages, we find that building emissions dominate over commuting emissions across the city, but commuting is increasingly important as building energy efficiency increases. Furthermore, our results indicate that efforts to improve a building's energy efficiency at Macquarie Park are largely negated by high reliance on car travel despite the introduction of the Epping–Chatswood train line. We conclude that improving building energy efficiency, office space utilisation and network connectivity (currently evident only in the CBD) delivers the best opportunity to reducing the carbon cost of workplaces.

本研究利用普查数据、全国建筑节能标准以及两幢建筑的上班路程和节能数据，考察悉 尼办公室人员的温室排放。通过对比中心商业区、麦考瑞公园地带和全市平均排放量，我们发现全市建筑排放普遍高于交通排放，但随着建筑能效的提高，交通排放所占比例 在增长。此外，研究结果显示，尽管修建了埃平-查特斯伍德铁路线，麦考瑞公园地带 的人们出行依然主要依靠小汽车，因此大大拉高了那里的建筑能效。因此，我们认为办 公空间的利用和网络连接性（目前仅限于CBD）是降低工作场所碳排放，提高建筑能 效的最佳途径。

Keywords::

• Journey to work
• office building energy
• greenhouse emissions
• transport

Acknowledgements

This article draws on data from an independent post occupancy evaluation for Workplace A that was undertaken by the first author for Stockland Pty Ltd. The authors acknowledge the range of stakeholders for Workplaces A and B who facilitated their administration of the Building Use Studies Questionnaire under licence and provided access to certified NABERS energy ratings.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

^1. The range given reflects the uncertainty behind the IPCC's (Intergovernmental Panel on Climate Change) climate change scenario modelling.

^2. In this broad conception of planning, we include everything from strategic metropolitan planning (including transport planning) to local planning and building code regulations.

^3. National Australian Building Environmental Rating Scheme (NABERS), NABERS Office: First developed in 1998 as Australian Building Greenhouse Rating (ABGR), the NABERS energy rating system is a protocol for benchmarking actual energy performance and CO₂-equivalent emissions post occupancy. It is currently administered by the New South Wales Government on behalf of commonwealth, state and territory governments.

^4. We use the term Macquarie Park throughout this article to refer to the 200 ha of commercial land-use area in the Macquarie Park Corridor which includes the three train stations Macquarie Park, Macquarie University and North Ryde (see Figure 4.5.51 in http://www.ryde.nsw.gov.au/_Documents/Dev-DCP/DCP10+P4-5.pdf).

^5. This assumes embodied energy = 14 GJ/m², emissions factor = 70 gCO₂e/MJ and a commercial building life of 80 years.

^6. This calculation assumes 20 m² gross workplace floor area per worker.

^7.The Building Use Studies (BUS) Workplace Questionnaire has been adopted in over 500 buildings worldwide. It has capacity to assess individual buildings against norms and best practice and to elicit feedback on a range of 63 variables including journey to work.

^8. Publicly available via the NSW Bureau of Transport Statistics.

^9. Mode information is limited to car driver, car passenger, train, bus, ferry/tram (combined as one category) and other. Records with the following modes were excluded: ‘Not stated’, ‘Did not go to work’ and ‘Worked from home’.

^10. See note 8.

^11. In this article Macquarie Park is defined by the following travel zones in 2006 and 2011: 2006: 2471, 2472, 2476, 2477, 2478, 2479, 2480, 2481, 2482, 2487, 2488, 2489, 2495, 2500. 2011: 1535, 1537, 1539, 1542, 1543, 1544, 1545, 1547, 1548, 1550, 1551, 1552, 1555, 1558.

^12. See Appendix B for more detail of how the main mode was specified in the Survey Data Sets.

^13. We assume four weeks of annual leave, nine days of public holidays and seven days of sick leave.

^14. Based on the ratio of the net lettable area of Tenancy to the net lettable area of Whole Building.

^15. A Workspace Ratio of 16.8 m²/person for Sydney CBD (December 2012) relative to 10-year average is reported.

^16. Personal communication with Jason Briffa, Buildcorp and Simon Xiberras, HBO+EMTB architects.

^17. We assume 2000 people work in a building with 24 000 m² NLA.

^18. Although there was no train line directly to the Macquarie Park area in 2006, there are still train trips in 2006 because some workers would catch the train to Epping or Chatswood stations and a bus from there, and these trips are recorded as having a main mode of train.

^19. Despite the attendant increase in heat loads that higher occupant densities can bring, a 6-Star level of performance is not inconceivable thanks to the cited improvements in building energy efficiency coupled with some level of low or zero carbon energy generation on site.

^20. See note 16.