The need to increase energy efficiency and reduce the carbon intensity of buildings has been well established, not least because, as acknowledged in the EU Energy Efficiency Action Plan 2011, the built environment offers greater potential savings than any other single area of activity, with

buildings estimated to be responsible for 30 - 40% of total energy use worldwide.

Current approaches to selecting energy retrofit solutions have not significantly changed since the drive to improve the energy efficiency of building stock arose in response to the 1970s oil crises. Selection is based primarily on predicted operational energy savings; the embodied energy represented by the materials has heretofore not been considered to be significant because firstly, it does not affect the financial return of the choice and secondly, as Ramesh et al. {Ramesh: 2010ff}, comment embodied energy (and carbon) has not been seen as significant vis-à-vis the operational energy consumption of a building over its life.

The primary objective behind current EU and national policies aimed at raising the energy efficiency of buildings is the reduction of greenhouse gases emissions - this contextual change means there is a disconnect between the policy drivers and the ‘on-the-ground’ decision-making for energy efficiency within buildings. Furthermore, as buildings become more energy efficient, operational energy consumption decreases and as a consequence the relative significance of embodied carbon increases. These changes mean that the on-going bias towards operational energy is no longer appropriate in decision-making on building energy retrofits.

This paper discusses the changing significance of embodied carbon in calculation of whole life carbon emissions of buildings, examines the factors behind these changes and, using a case study, presents the case for including embodied carbon in a holistic decision-making process for planning building energy retrofits.