Energy conservation and carbon emissions reduction are ways of mitigating the damage caused to the environment as a result of greenhouse gas emissions. All activities that consume energy also produce carbon dioxide (CO2), which, in turn, contributes to greenhouse gas emissions. Energy use in buildings accounts for 40-50% of the UK's CO2 emissions, and the residential sector contributes more than half of these emissions.udThe Climate Change Act (2008) has committed to reducing the UK's current carbon dioxide emissions by 80% by 2050. The Act is considered the primary mechanism for achieving the desired cut in emissions and it requires local authorities to draw up plans to improve their domestic energy efficiency by 30% over the next 10-15 years. The Department of the Environment, Transport, and Regions (DETR) has estimated that a 30% reduction in domestic energy consumption is possible through energy conservation and efficiency without effecting services standards. Considering that new builds represent just 1% of the overall housing stock, action must be taken to renovate existing dwellings in order to improve their energy efficiency.udThese renovations, however, must be considered in the light of embodied energy that will be consumed in their undertaking. In this case, embodied energy comprises all the energy inputs that are needed to manufacture the material elements of the building that are being renovated. Great care must be taken to ensure that embodied energy consumed is considered when planning renovations to existing housing stock.udThis thesis will document how the required reduction in the greenhouse gas emissions from the UK housing stock can be achieved and to outline ways of reducing the impact of domestic emissions on the environment, considering at all times, the embodied energy that is required to do so. Secondly, it aims to provide efficient homes with lower energy bills and to convince householders to implement appropriate retrofit solutions to improve the energy efficiency of their dwellings.udTo achieve this, the Cambridge Housing Model 2010 was used as a direct source of housing data in order to create an embodied energy model that allow a direct comparison of the embodied energy and the operational energy gains and various refurbishment strategies.udThis model was used to test various de-carbonisation scenarios that build towards achieving the targeted reduction in CO2 emissions. This entailed the identification of the optimal insulation of eachud12udbuilding element, refurbishing the building fabric, insstalling double-glazing and installing more efficient building systems.udOutputs from these scenarios were compared with regard to energy consumption (both embodied and operational), cost and CO2 emissions, to predict the most efficient and cost-effective scenario for the entire UK housing stock.udThe results of this study show that embodied energy is a vital factor because the lower the embodied energy of the insulation, the greater the energy conservation and the shorter the payback periods for any renovation.udThis study also has found that mineral wool was the most efficient cavity wall insulation, whereas the optimal insulants for warm- and cold-pitched roofs were expanded polystyrene (EPS) and cellular glass, respectively. Cellular glass was the only applicable insulation for internal and external walls and sheep wool was far more efficient for floor insulation.udThe analysis conducted confirmed the findings outlined in the literature review that suggested embodied energy is a significant contributor to energy efficiency. Further results have also shown that retrofitting a dwelling’s fabric and building services systems can considerably improve energy performance and help to achieve the energy efficiency standards that have been set by the UK government.udFinally, this research has proven that retrofitting, as opposed to rebuilding, is the most practical and feasible solution to achieving the desired emissions reductions by 2050.
展开▼
