The role of aesthetics in energy-retrofit strategies: the case of solid wall houses in the UK

Seifhashemi, SM 2021, The role of aesthetics in energy-retrofit strategies: the case of solid wall houses in the UK , PhD thesis, University of Salford.

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Solid wall dwellings are responsible for 36% of the carbon emission from the domestic sector in the UK. Among energy retrofit measures, Solid Wall Insulation (SWI) is the most effective in reducing energy demand. However, the current rate for insulation of solid walls is lower than desired in the UK, and only 9% of solid wall houses are insulated. To meet the 2050 net-zero emissions target, a higher rate of insulation is required to improve the energy efficiency of old stock. Innovative and encouraging retrofit plans are urgently required to unlock the demand for SWI, which will improve the energy performance of old dwellings. This study aims to contribute toward an innovative solution for the uptake of Internal Solid Wall Insulation (ISWI) demand in the energy technology industry. Two interconnected gaps in the literature were identified. One gap is the lack of clear information on the performance benefits of SWI as a single retrofit measure in solid wall homes, which is a cause of uncertainty for householders. This uncertainty about potential energy savings arising from the U-values of walls in solid wall properties has led to under- or over-estimation of SWI performance. The second gap is the need for innovative solutions to unlock the demand for slow progressed SWI in the UK. In home improvement, the aesthetic factor is seen as a trigger for renovation to start. Aesthetic renovation is more of an issue for internal spaces and is happening routinely as a voluntary approach by residents. Hence, the idea of integrating the aesthetic factor in ISWI is recommended in this study for the first time, and its importance in renovation for householders and in the uptake of ISWI is evaluated. To address the knowledge gap about ISWI energy-saving benefits, an energy assessment phase is designed in this research to contribute to providing clear information about the benefits of ISWI itself for a variety of identified U-values for solid brick walls using the developed validated model of the Salford Energy House testing facility with a negligible model performance error. For the second gap, aesthetic inclusion in ISWI and its impact on householders’ views towards the uptake of ISWI is evaluated using an online survey. The results from both phases of this research are then used to provide recommendations for policy makers, the retrofit industry, and designers, in support of the acceleration of ISWI in the uninsulated UK stock. The focus of the energy assessment phase (Phase 1) was on U-value variation as the key parameter for energy-saving evaluations. The energy performance of pre-and post-IWI in the Salford Energy House (SEH) is investigated; this is a replica of a pre-1919 Victorian solid wall terraced house. The modelling software IES-VE was used to develop a model for the SEH, and this model was validated against collected experimental data. The baseline solid wall Uvalue for SEH changed between 0.64-2.48 W/m²K to model different solid walls before insulation and the benefits of insulation assessed. The result of this phase contributes towards a better understanding of the energy saving potential of IWI within the UK and provides a more realistic picture of its benefits for policymakers and relevant stakeholders. Based on the results, the annual heating energy saving varies significantly depending on the baseline wall U-values, ranging from 19% to 46.2%. The difference of cost saving potentials between the cases with the lowest and highest baseline wall Uvalues is also high, with variance per year being £228. Thermal comfort (18°C<T<=23°C) was also evaluated for the selected case study with different baseline wall U-values. It was found that the thermal comfort improved with wall insulation while at the same time overheating is not significant for the case study using Manchester weather data. In the aesthetic evaluation phase, the second phase of this research, people’s preferences for aesthetics in renovation and its potential in promoting SWI was explored using an online survey. The data from the collected validated 273 responses was analysed using SPSS software. The results show that aesthetics is a very important factor for most of the participants, since the aesthetic is found to be rated more than 90% important to participants, which is in line with cost and energy saving factors in internal renovations. This result also confirms that including the aesthetics of wall insulation can challenge the negative view of participants on losing internal space, where the disagreement level is only 10%. Additionally, the preferences of participants towards aesthetics can surpass the concerns of cost since 88.6% of participants are willing to pay more to achieve an aesthetically appealing insulation product. Furthermore, the views of participants were explored with respect to insulating the walls with internal aesthetic panels, which offer aesthetic and energy saving in a single package, and more than 50% of participants stated their willingness. From the results, more than 2/3rd of participants also agreed with delivering both aesthetic and energy improvement in combined retrofit plans by established organisations. The significance of the aesthetic factor in renovation and its inclusion in planning the SWI strategies, especially for IWI, are proven by the results of this study. In conclusion, it is necessary to boost the SWI intake with the highest potential energy saving compared to other retrofit measures in treating the uninsulated properties. It is recommended that policy makers include the aesthetic in planning the SWI strategies to trigger its uptake. It is beneficial when interior designers and product designers contribute to the engagement of householders to raise awareness of the benefits from Internal Aesthetic Wall Insulation (IAWI). This will unlock the demand for IWI by increasing the number of potential customers and lowering the financial concerns of households. It is also recommended that financial support be extended to cover the redecorating cost after installation of IWI. Home improvement and energy retrofit companies should come together to work closely in an integrated approach to encourage IAWI for retrofitting old houses. IAWI does not only provide energy saving but also the aesthetic improvement of internal spaces can be achieved. Furthermore, establishment of organisations to centralise the retrofit measures of old housing stock is recommended to offer both energy saving and aesthetic incentives to householders at the same time. This is to ensure that householders are supported during the entire retrofit process in the design, supervision, after care process, professional-quality delivery of the project, subsidies application, cost and time frame of the retrofit project while receiving the aesthetic and energy saving benefits at the same time.

Item Type: Thesis (PhD)
Contributors: Elkadi, HA (Supervisor)
Schools: Schools > School of the Built Environment
Depositing User: SM Seifhashemi
Date Deposited: 13 Oct 2022 08:30
Last Modified: 13 Oct 2022 08:30

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