The impact of high voltage overhead power lines on the value of residential property in the United Kingdom
This thesis investigates the impact of electricity distribution equipment on the value of residential units in the UK. This is a complex task, due to the potential influence on the market from the publics' perception of a perceived link between living in close proximity to high voltage overhead power lines (HVOTLs) and a number of adverse health effects. A review of the literature revealed that no previous studies had been undertaken within the UK to establish the impact of HVOTLs on house prices and as such, identified a gap in knowledge within the UK and provided a focus for this thesis. Due to a lack of available transaction data in England, investigating the impact on house price relies entirely on the use of qualitative research methods. Therefore to test the accuracy of the results from the perceptual study, a benchmark was developed using transaction data obtained from a residential housing estate in Blackwood, Scotland where a HYOTL was present. The thesis begins with an overview of the current planning and development controls relating to the siting of electricity distribution equipment and the subsequent development of land near HYOTLs. A critical review of the literature is presented which, due to the perceived relationship between living near HVOTLs and a health risk, includes literature on other related areas, for instance, property stigma, risk analysis and scientific and epidemiological studies on the possible health effects. ' A multimethod approach is adopted towards data gathering, using both qualitative and quantitative research paradigms. Buyers' and valuers' perceptions of the impact of a HYOTL on value are obtained using postal surveys and interviews. Additional information is gathered from the electricity utilities, residential developers and government planning departments. Using a case study approach and a hedonic pricing methodology (to enable the relationship between a HYOTL and house price to be explored), selling price data and asking price data from three locations were gathered and analysed. Regression analysis established that a INOTL near a residential unit does have an impact on house price, although this impact is not always negative. The results from three case studies, the opinion surveys and the interviews are compared, indicating that opinion surveys may result in an underestimation of the impact of a HYOTL on selling price and, by contrast, appraisers may overestimate the negative impact of HVOTLs on asking price when marketing a house. The results suggest reliance on one method may prove misleading and therefore the use of a multimethod approach towards data collection may improve the reliability of findings.