AbstractMitigating the environmental impacts of the built environment is at the centre of attention for researchers, international commissions, legislative bodies, and policy makers. The UK has set an ambitious national target for a 100% reduction in GHG emissions by 2050 (against 1990 levels). Current operational energy consumption by the residential sector constitutes 15% of these emissions. Energy performance improvements of existing homes play a substantial role in the achievement of this target. The UK is however facing a major challenge to introduce retrofit measures as it inherits one of the oldest, most culturally rich housing stocks in Europe. Traditional dwellings make up a large part of the UK housing stock; they are generally poorly performing but also of high architectural and/or historic value. However, their contribution to decarbonisation has not yet been fully realised because of a range of difficulties surrounding the application of energy retrofit interventions to this part of the stock. The main hurdles are due to the risks imposed to their heritage value and to the thermo-hygrometric balance of their constructions.
The aim of this research is to propose a systemic approach to intervene in Traditional Listed Dwellings (TLDs) to improve their energy performance and shape a more future-proof heritage. A mixed methodology has been developed that utilises C19th TLD case studies in the South-East of England, to investigate their current energy performance and the possible improvements using responsible, safe, and effective energy retrofit scenarios. A critical comprehensive review of literature was followed by collection of data through secondary sources. Primary data has been collected through visual and measured surveys, questionnaires, interviews, utility bills, meter-readings, data-logging and thermal-imaging. The output of this stage was used to feed into the next data generation stage via energy simulation applications. Passive retrofit solutions were devised and simulated, individually and combined, to investigate their impact on the energy efficiency of the selected case studies, alongside the potential risks to their heritage value and the thermo-hygrometric balance of their constructions. The use of mixed methods, multiple case studies and multiple units of analysis facilitated the triangulation of findings, which enhanced the validity and reliability of the results of the energy simulation. Finally, the parametric analysis of the proposed solutions permitted the development of packages of responsible, safe and effective retrofit interventions and a sensitivity analysis of the simulation results highlighted the areas of the envelope where appropriate interventions were more likely to generate the highest energy and carbon savings.
The results of this study highlight the major importance of draught-proofing (amongst the low-risk measures) and of interventions in wall constructions (amongst the medium- and/or high-risk measures). However, the triangulation of findings challenged the actual effectiveness of retrofit measures for walls when it was shown that savings made in heating energy can be counteracted by high level of risk imposed to the heritage value and to the thermo-hygrometric balance of the envelope. This contrasts with the level of interventions applicable to windows, which can result in higher reductions in energy consumption. The findings of this study show that the range of baseline conditions and limitations imposed by heritage value and condensation risk are the main determinants of the amount of energy and carbon savings obtainable by means of suitable retrofit interventions.
This study demonstrated that, although individual assessment of TLDs remains essential to devise a safe, responsible, and effective retrofit package, which not only improves energy performance and decrease carbon emissions but also respects heritage characteristics of the building, it is possible to devise a comprehensive, systemic methodology for intervention in this particular part of the stock with an aim to create more generalisable solutions applicable to a wider population of buildings of heritage value. The major contribution of this study, which is a holistic and tiered methodology, is unprecedented. This in-depth analysis methodology was applied to a number of representative TLD CSs, and can be replicated in a wider, similar or different context. The results can be generalised to be directly used for a series of suitable interventions in other parts of this stock and demonstrate the largely unexplored potentialities for energy consumption and carbon emissions reduction inherent in a responsible and safe retrofit of TLDs.
|Date of Award||Jul 2022|
|Supervisor||Noel Painting (Supervisor) & Poorang Piroozfar (Supervisor)|