Agents of Change in the Domestic Built Environment

As our cities age, a large number of spatial structures experience physical change. A better understanding of what this process may entail and the agents involved in it can extend the knowledge of practitioners, activists, and policy experts regarding the resilience of our domestic building stock and cities. Awan et al. (2013) explain that agents are not entirely free from societal and spatial constraints; instead, they are characterised by intent, shaped by their own visions and actions, and context, the spatial and social structures of which they are part and which they negotiate. This article discusses the intent and context of the agents involved in the construction and transformation of the Cité Ouvrière in Mulhouse in Eastern France from the mid-19th century to date. With 1,253 houses built for the workers of the Dollfus-Mieg et Compagnie (DMC) textile factory between 1853 and 1897, Cité Ouvrière was the largest and most successful employer-constructed housing scheme of its time, setting an example for many other European company towns. Through this exceptional case study, the article identifies the levels at which spatial agents operate, the means they use to instigate change, their dynamic relations, and the ways these are influenced by the wider historical context while influencing the making and evolution of the built form. Using historical and archival documents, it amounts to recognise an interplay of individuals and public and private groups, who have been responsible for taking decisions at different scales—the city, the neighbourhood, and the houses—and have instigated changes of different effect—from more localised to more aggregate.

Radiant Conditioning Retrofitting for Residential Buildings

In order to achieve Australia’s greenhouse gas emissions reduction targets, a majority of the existing residential building stock in Australia will require retrofitting in favour of energy-efficient solutions. This paper considers retrofitting for conditioning to be one of the most straightforward and offers the greatest potential to deliver significant comfort and energy-saving results. Radiant conditioning systems are not new, yet some game-changing innovations have taken place over the last decade that may require an entire paradigm shift in the manner we condition our buildings. The reiteration of the principle ‘thermally active systems’ suggests that our buildings need to accommodate these systems into the fabric of building components. However, extremely few products and/or innovative solutions for doing such seem to be provided by the industry. We seem incompetent with solutions that are not costing the Earth, insulating, lightweight, and offering an instant response time to conditioning. We still have the concept embedded in our minds that radiative systems consist of heavy ‘combat’ construction with time lags of a day or two and that they are very costly to implement, especially if we are to retrofit a project. The purpose of this paper is to rectify and change our understanding of radiant systems, namely through a review of the existing technology and its recent advancements. It intends to introduce the fact that radiant systems can become highly reactive, responsive, and thermally dynamic conditioning systems. Lightweight radiant systems can be 40% more energy-efficient than common air conditioners and can respond in less than 15 min rather than in the hours required of heavy radiant systems. Thus, an insulated, lightweight radiant system is ideal for retrofitting residential buildings. Furthermore, this paper supports and introduces various systems suited to retrofitting a residential building with hydronic radiant systems.

Long-Term Techno-Economic Performance Monitoring to Promote Built Environment Decarbonisation and Digital Transformation—A Case Study

Buildings’ long-term techno-economic performance monitoring is critical for benchmarking in order to reduce costs and environmental impact while providing adequate services. Reliable building stock performance data provide a fundamental knowledge foundation for evidence-based energy efficiency interventions and decarbonisation strategies. Simply put, an adequate understanding of building performance is required to reduce energy consumption, as well as associated costs and emissions. In this framework, Variable-base degree-days-based methods have been widely used for weather normalisation of energy statistics and energy monitoring for Measurement and Verification (M & V) purposes. The base temperature used to calculate degree-days is determined by building thermal characteristics, operation strategies, and occupant behaviour, and thus varies from building to building. In this paper, we develop a variable-base degrees days regression model, typically used for energy monitoring and M & V, using a “proxy” variable, the cost of energy services. The study’s goal is to assess the applicability of this type of model as a screening tool to analyse the impact of efficiency measures, as well as to understand the evolution of performance over time, and we test it on nine public schools in the Northern Italian city of Seregno. While not as accurate as M & V techniques, this regression-based approach can be a low-cost tool for tracking performance over time using cost data typically available in digital format and can work reasonably well with limited resolution, such as monthly data. The modelling methodology is simple, scalable and can be automated further, contributing to long-term techno-economic performance monitoring of building stock in the context of incremental built environment digitalization.

Reed as a Thermal Insulation Material: Experimental Characterisation of the Physical and Thermal Properties

The building sector plays a significant role in reducing global energy use and carbon emissions. In the European Union (EU), the building stock represents 40% of total energy use and in which cooling and heating systems represent over 50%. Portugal is one of the EU countries where the consequences of energy poverty are most evident due to the families' financial inability to adequately climate their homes. The reasons are several, but they are mainly linked to buildings' poor passive thermal performance, resulting from inadequate adaptation to the climatic context and reduced thermal insulation. Thus, it is necessary to develop solutions to increase buildings’ thermal performance and reduce their potential environmental impact, which arises mainly from the significant use of active systems. In this sense, natural building materials are a promising solution, reducing energy use and carbon emissions related to buildings. This research studies the potential use of reed found in Portugal (Arundo donax) as a thermal insulation material. Its physical characterisation and the influence of geometry configuration on its thermal performance are evaluated. Its durability was studied too. Reed stalks were used to carry out the physical and durability tests. A reed board (150 x 150 mm) was built, and its thermal performance was tested in a hotbox. According to the results, the characteristics of reeds found in Portugal make it suitable to be used as a building material. Furthermore, regardless of the configuration studied, the reeds have a satisfactory thermal performance to be used as thermal insulation, under the requirements defined by Portuguese thermal regulation, Re ≥ 0.30 (m2.oC)/W. There is a trend to the mould growth in the reed, but only under favourable conditions. Additionally, considering the abundance of reed throughout the Portuguese territory, this is an eco-friendly and low-cost option that gathers all requirements to be more used in the construction market.

Empirical and Numerical Analysis of an Opaque Ventilated Facade with Windows Openings under Mediterranean Climate Conditions

In recent years, there has been growing concern regarding energy efficiency in the building sector with energy requirements increasing worldwide and now responsible for about 40% of final energy consumption in Europe. Previous research has shown that ventilated façades help to reduce energy use when cooling buildings in hot and temperate climates. Of the different ventilated façade configurations reported in the literature, the configuration of ventilated façade with window rarely has been studied, and its 3D thermodynamic behavior is deserving of further analysis and modeling. This paper examines the thermal behavior of an opaque ventilated façade with a window, in experimentally and numerical terms and its impact in energy savings to get indoor comfort. Field measurements were conducted during the winter, spring and summer seasons of 2021 using outdoor full scale test cells located in Seville (southern Spain). The modeling of the ventilated façade was carried out using a three-dimensional approach taking into account the 3D behavior of the air flow in the air cavity due to the presence of the window. The validation and comparison process using experimental data showed that the proposed model provided good results from quantitative and qualitative point of view. The reduction of the heat flux was assessed by comparing the energy performance of a ventilated façade with that of an unventilated façade. Both experimental and numerical results showed that the ventilated façade provided a reduction in annual total energy consumption when compared to the unventilated façade, being compensated the winter energy penalization by the summer energy savings. This reduction is about 21% for the whole typical climatic year showing the ability of the opaque ventilated façade studied to reduce energy consumption to insure indoor comfort, making its suitable for use in retrofitting the energy-obsolete building stock built in Spain in the middle decades of the 20 century.

Linking Energy Poverty with Thermal Building Regulations and Energy Efficiency Policies in Portugal

Energy-poverty (EP) must be considered an energy-related issue since buildings are a central part of people’s daily lives. Thus, it has an important role in energy-related policy implementation. Even though the European Union (EU) has endorsed general energy efficiency through the Energy Efficiency Directive and Energy Performance of Buildings Directive recast, it was the Clean Energy Package for all Europeans that clearly highlighted EP. The growing concerns with EP have also been emphasised in subsequent directives and initiatives. Despite some regulatory framework and the milder climate situation, the proportion of the population experiencing thermal discomfort in southern and eastern European countries, namely in the winter season, is relatively high, reflecting the poor thermal performance of building stock, low family incomes and high energy prices, among others. The current work analysed the EP evolution in Portugal in the EU context, and the Thermal Building Regulations and Energy Efficiency Policies developed, aiming to add insight into the effectiveness of those policies concerning EP mitigation in Portugal as an EU Member state. Moreover, a critical debate on the potential to lower the EP Portuguese situation was also an objective to pursue. It is plausible to admit that reducing EP by acting on residential building stock, namely through the increase of energy efficiency and comfort, plays a key role in improving the living conditions, namely of vulnerable households and deprived areas. This will also decrease energy consumption and dependence while further promoting a smarter, sustainable and inclusive society, contributing to economic growth.