Measuring the carbon footprint of existing office space

Abstract

Methods for assessing the environmental performance of new and existing office space cover a range of criteria that includes energy, water, materials and waste, health and wellbeing, pollution, transport, land use and ecology, but the overwhelming environmental objective is to reduce the amount of carbon dioxide (CO₂) emitted from office use. The two main sources of office‐related CO₂ emissions are building operation and commuting and, in these respects, existing buildings pose a different set of challenges to new developments; energy is embodied in the existing structure and systems, and the location is fixed in relation to facilities such as public transport nodes and amenities. Using standardised published metrics on CO₂ emission from office occupation and commuting, this paper estimates the amount of CO₂ emitted by the stock of medium to large office buildings in a large regional city in the UK. The results are put into context of government targets and current environmental performance assessment methods. The paper argues that the existing office stock of a typical UK city performs poorly in terms of CO₂ emission and that most current assessment instruments do not reveal the full extent of that poor performance. Depending on the instrument, this is for one or more of three main reasons: actual energy consumed/CO₂ emitted is not measured, insufficient weight is placed on CO₂ emission relative to other, often more qualitative green credentials, and either insufficient or no regard is paid to CO₂ emitted as a result of commuting and business travel.

Keywords:

• offices
• occupation
• environmental performance
• measurement
• carbon dioxide (CO₂)

Acknowledgements

The research on which this paper is based is part of a two‐year study that was funded by King Sturge LLP and the University of the West of England. The authors are very grateful for the support of staff at the Bristol office of King Sturge LLP who supplied data and expertise throughout the project.

Notes

1. Relative location means the topology (proximity, connectivity and adjacency) of land uses.

2. Each mode has a mix of economic, social and environmental costs and differs in terms of the extent to which these costs are externalised by the firm.

3. Communications networks such as broadband, land‐lines and mobile networks might be regarded as substitutes for physical transport networks.

4. Available from: http://www.communities.gov.uk/documents/planningandbuilding/xls/1179479.xls

5. According to figures from the University of the West of England’s travel planner (April 2008).

6. See http://www.ipd.com/Default.aspx?tabid=2029

7. See http://www.les-ter.org

8. The two office buildings near Bristol Temple Meads railway station would be included if the route network used to calculate accessibility included pedestrian routes rather than roads only.

9. Available from https://www.energystar.gov/istar/pmpam/