• Energy Research

Earthen heritage is one of the oldest and universal forms of heritage but its conservation poses many challenges. Establishing international collaborations could provide an efficient, sustainable mechanism to increase knowledge exchange, aiding the development of earthen heritage conservation strategies around the world. However, perceived differences in how Eastern and Western countries value earthen heritage and develop conservation strategies can pose challenges for establishing collaborations. To understand these perceived differences and whether they hinder collaborations, this paper compares British and Chinese heritage conservation policy and practice and then reports the results from an innovative workshop examining the approaches of 13 Chinese and 13 UK based heritage experts and researchers towards earthen heritage conservation. Workshop participants undertook bilingual discussions and completed a co-created questionnaire available in English and Mandarin. Both groups identified historic value as the most important value and maintenance of authenticity and integrity, need for scientific research and site scale conservation as vital considerations for conservation strategies. This study found that to understand the potential for collaboration, individual perspectives need consideration as well as policies and practices. This innovative bilingual, discussion-based approach has potential to aid collaborations for diverse international issues from wildlife conservation to cross-boundary pollution and climate change.

Earthen heritage is one of the oldest and universal forms of heritage but its conservation poses many challenges. Establishing international collaborations could provide an efficient, sustainable mechanism to increase knowledge exchange, aiding the development of earthen heritage conservation strategies around the world. However, perceived differences in how Eastern and Western countries value earthen heritage and develop conservation strategies can pose challenges for establishing collaborations. To understand these perceived differences and whether they hinder collaborations, this paper compares British and Chinese heritage conservation policy and practice and then reports the results from an innovative workshop examining the approaches of 13 Chinese and 13 UK based heritage experts and researchers towards earthen heritage conservation. Workshop participants undertook bilingual discussions and completed a co-created questionnaire available in English and Mandarin. Both groups identified historic value as the most important value and maintenance of authenticity and integrity, need for scientific research and site scale conservation as vital considerations for conservation strategies. This study found that to understand the potential for collaboration, individual perspectives need consideration as well as policies and practices. This innovative bilingual, discussion-based approach has potential to aid collaborations for diverse international issues from wildlife conservation to cross-boundary pollution and climate change.

With approximately 40% of the London building stock built before 1919, internal wall insulation (IWI) is one of the likely measures for deep retrofit to meet carbon emissions targets. However, IWI can lead to moisture accumulation and associated unintended consequences, especially in walls highly exposed to wind-driven rain (WDR). Climate change is predicted to exacerbate WDR exposure. This paper presents a comparative analysis between the hygrothermal performance of IWI under current and far future (2080) climates. Historic weather station data and UKCP18 climate projections were used to develop weather files for simulating current and future climate, respectively. Hygrothermal simulations were performed using DELPHIN. Assemblies include calcium silicate, phenolic foam, and wood fibre systems. Future climate predictions are associated with a rise of interstitial relative humidity, leading to patterns more favourable to mould growth.

With approximately 40% of the London building stock built before 1919, internal wall insulation (IWI) is one of the likely measures for deep retrofit to meet carbon emissions targets. However, IWI can lead to moisture accumulation and associated unintended consequences, especially in walls highly exposed to wind-driven rain (WDR). Climate change is predicted to exacerbate WDR exposure. This paper presents a comparative analysis between the hygrothermal performance of IWI under current and far future (2080) climates. Historic weather station data and UKCP18 climate projections were used to develop weather files for simulating current and future climate, respectively. Hygrothermal simulations were performed using DELPHIN. Assemblies include calcium silicate, phenolic foam, and wood fibre systems. Future climate predictions are associated with a rise of interstitial relative humidity, leading to patterns more favourable to mould growth.

ISO standard 15927-3 characterise episodic exposures of wind-driven rain (WDR) on building façades by identifying wetting intervals, referred to as spells. Spells separated by 96 h or more without WDR are considered, assuming that this interval is sufficient for evaporative losses to exceed prior rainwater gains. This approach ignores variations in evaporation due to the façade orientation and local environmental factors, which cause diverse drying intervals even for the same material. This study proposes an estimation of potential evaporation losses in façades, considering their orientation and local climate. Representative drying intervals and enhanced façade-specific WDR spells are identified by combining potential evaporation losses with the directional WDR exposure. The results at locations in The Netherlands and Spain demonstrates that the drying intervals can vary significantly depending on these factors (regardless of the surface materials), which suggests reconsidering the current 96-h ISO model to minimise uncertainties when characterising episodic WDR exposures.

ISO standard 15927-3 characterise episodic exposures of wind-driven rain (WDR) on building façades by identifying wetting intervals, referred to as spells. Spells separated by 96 h or more without WDR are considered, assuming that this interval is sufficient for evaporative losses to exceed prior rainwater gains. This approach ignores variations in evaporation due to the façade orientation and local environmental factors, which cause diverse drying intervals even for the same material. This study proposes an estimation of potential evaporation losses in façades, considering their orientation and local climate. Representative drying intervals and enhanced façade-specific WDR spells are identified by combining potential evaporation losses with the directional WDR exposure. The results at locations in The Netherlands and Spain demonstrates that the drying intervals can vary significantly depending on these factors (regardless of the surface materials), which suggests reconsidering the current 96-h ISO model to minimise uncertainties when characterising episodic WDR exposures.

The conservation of cultural heritage built of historical brick masonry alongside meeting targets in energy reduction will most likely require widespread installation of internal wall insulation (IWI). In London, traditional buildings (pre-1919) make up 40% of the existing stock and insulating from the interior is a likely retrofit solution for solid brick walls. Adding insulation may introduce a higher risk to moisture accumulation and consequences such as mould growth and material decay. To investigate resilience to future moisture loads, three interior insulation assemblies (conforming to two U-value guidelines) were simulated in DELPHIN under reference, near-future (2040), and far-future climate (2080) scenarios. Calcium silicate, phenolic foam, and wood fibre assemblies were simulated. The reference year climate file was compiled from observed data and future files developed using the UK Climate Projections 2018 (UKCP18). Assemblies were evaluated for moisture accumulation, mould growth risk, and freeze-thaw (FT) risk. Results show low-to-medium risks in 2040 and high risks in 2080, assemblies of higher absorptivity and thinner insulation comparatively performing best. The calcium silicate assembly fared best for moisture performance; however, all assemblies will be subject to high moisture risk levels in the far future and responsible retrofits must take this and alternative design solutions into account.