Moving towards low-carbon buildings and cities: experiences from Oxford, UK

Abstract

This paper reviews two key initiatives undertaken in the historical city of Oxford to bring about reductions in energy-related CO2 emissions on a dwelling-level as well as city-wide scale, using both bottom-up and top-down carbon-counting approaches. The development and application of a bottom-up carbon-counting approach called DECoRuM is described. DECoRuM is a Geographical Information System-based software model which estimates and maps baseline energy use and CO2 emissions on a house-by-house level, identifies ‘pollution’ hotspots, predicts the potential for reductions in CO2 emissions and monitors reductions achieved as a result of deploying energy efficiency measures and renewable energy systems. The application of DECoRuM model to a case study in Oxford shows that CO2 emission reductions above 60% are possible, at a cost of between £6 and £77 per tonne of CO2 emissions saved, depending upon the package of measures used and the scenario of capital costs (low or high) employed. Alongside DECoRuM, the author has led the development of an action-oriented Oxford Climate Change Action Plan (OCCAP) which uses top-down approaches to construct an accurate CO2 emissions inventory for Oxford city for a baseline year, establish CO2 reduction targets and propose action for each of the energy-related sectors to meet those targets. These two different, but complimentary, approaches provide a useful example for other cities in their endeavour for emission reductions.