Benchmarking the energy use of historic dwellings in Bath and the role for retrofit and LZC technologies to reduce CO2 emissions

Student thesis: Doctoral ThesisPhD


Historic dwellings in the UK make up 20% of all homes and are amongst the most poorly performing part of the English housing stock in energy use terms, with the lowest SAP rating and highest average annual CO2 emissions. The degree to which proposals to retrofit the UK housing stock can reduce emissions depends on current energy use and CO2 emissions. Current methodology relies on national aggregated statistics to provide average energy use data; historic buildings as a subset cannot be segregated.In order to assess realistic carbon reduction potential it is vital that performance of historic dwellings is established from disaggregated data sources or with validated and stakeholder accepted models that can accurately prescribe energy use in an affordable, easy to use and transparent manner. This research attempts to begin such orthodoxy.The benchmark derived in this study suggests that historic buildings in Bath use less energy than predicted by national, regional, and local average energy use, but they are not low energy dwellings. They therefore require retrofit adaptations to reduce CO2 emissions. Procedures to assess the potential for such measures are of primary importance as some adaptations impact on both fabric and aesthetics. It is therefore imperative that the contribution such alterations make towards reducing CO2 emissions can be weighed against the change they may make to our built heritage.Using the Passive House Planning Package modelling tool, predictions of energy use were provided and validated against actual energy use. The model demonstrated accuracy in predicting energy used when incorporating a reduction factor to reflect intermittent heating patterns. The model was then used to assess the retrofit adaptation measures with a suite of measures incorporating renewable energy technology, delivering CO2 emission reductions approaching 80%. This approach can be applied beyond the UK as the model permits the use of local weather data sets.In establishing a benchmark of energy use in domestic historic dwellings, this work assists in developing suitable and effective solutions that are replicable and durable, permitting built heritage to meet UK emissions targets through the provision of empirical data to evaluate any alteration to fabric or aesthetics against the benefit of carbon savings.
Date of Award1 Aug 2013
Original languageEnglish
Awarding Institution
  • University of Bath
SupervisorSukumar Natarajan (Supervisor), Maria-Heleni Nikolopoulou (Supervisor) & Dina D'Ayala (Supervisor)


  • energy
  • carbon emissions
  • historic buildings

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