Papers by Stavroula Thravalou
I n te r n a ti o n a l C o n f e r e n ce o f B i o -B a se d E c o no m y f o r A p p l i ca t ... more I n te r n a ti o n a l C o n f e r e n ce o f B i o -B a se d E c o no m y f o r A p p l i ca t i o n a n d U t i li z a ti o n b i t . l y/ i c b e a u 2 0 2 0 2 n d I C B E A U 2 0 2 0 A s si s t a n t
Delivering Education on the Sustainable Aspects of Heritage
Communications in computer and information science, Dec 31, 2023
In response to the need for educational practices and approaches to be updated within the area of... more In response to the need for educational practices and approaches to be updated within the area of sustainable heritage, this paper presents the lessons and good practices derived from two European Erasmus Plus projects (HERSUS and Smart Rehabilitation 3.0). These projects strive to create an innovative new framework that integrates vital educational challenges in the field of sustainability in heritage. Among the prime concerns of these research projects are to challenge different problems related to heritage conservation, generate sustainable-based approaches, and finally, create a homogeneous curriculum for experts in rehabilitation and sustainability. The major research outcomes presented for the purpose of this paper are the creation of, a) an innovative integrated Master’s course on heritage and sustainability, with new developed courses offered from five different European Universities; b) a series of remote-access Massive Online Courses (MOOCs); and c) a number of digital tools promoting open access in education, such as a sharing platform and an online database for technological innovations and best practices for sustainable conservation through case studies. The conclusions highlight the benefits of adopting innovative, integrated approaches and digital tools for teaching, contributing to the delivery of lifelong learning opportunities, while bridging the gap between sustainability and built heritage awareness.
Technical Annals, 2023
In response to today’s contemporary challenge regarding how to tackle the effects of climate chan... more In response to today’s contemporary challenge regarding how to tackle the effects of climate change in heritage environments, natural ventilation arises as a compatible, low-cost and environmentally friendly passive cooling strategy for the Mediterranean climate. However, an identified research gap concerns the lack of studies addressing data from both the urban and building scales. An innovative, multi-scale approach is introduced in this research, through the study of airflow on the neighbourhood, street canyon and building scales, which is then evaluated using field measurements. The effect of urban density and street-canyon geometry on indoor thermal comfort is discussed in the case of adobe buildings with pass-through spaces (portico), and timber projections with multiple openings (sahnisi). The originality of the presented research lies in the adopted multi-scale methodology. On the district level of study, analytical tools and urban-scale considerations in the development of ...
IOP Conference Series: Earth and Environmental Science, 2023
Dynamic simulation tools are widely used in the workflow of energy retrofitting historic building... more Dynamic simulation tools are widely used in the workflow of energy retrofitting historic buildings as they contribute to the development of an optimised, cost-effective renovation strategy. Additionally, Building Information Modelling (BIM) applied in heritage buildings can provide a holistic platform that improves collaboration between different stakeholders involved in the management, restoration and energy-retrofit of heritage buildings, by facilitating data sharing and project coordination. However, the use of BIM for energy simulation is rarely implemented due to emerging technical complexities regarding data interoperability. In response to the above shortcomings, the paper addresses the challenges of integrating a) dynamic energy performance analysis and b) financial feasibility analysis, using Heritage-BIM (H-BIM) tools. Insights and knowledge acquired through the case of a deep renovation of a historic building in ruin condition is presented. Specifically, an integrated H-BIM approach was developed by the authors in order to propose cost-effective energy efficiency upgrade measures. The energy improvement measures concern the upgrade of the thermal transmission of the building envelope, the incorporation of efficient heating, cooling and mechanical ventilation systems, as well as the incorporation of renewable energy systems. The economic feasibility study is based on widely used financial indicators, including life cycle cost analysis (LCCA). The proposed workflow aims to become a useful methodological tool for public authorities, assisting the attraction of financing mechanisms for the restoration and energy-upgrade of the historic building stock.
IOP Conference Series: Earth and Environmental Science, 2023
Vernacular architecture employs numerous elements for enhancing natural ventilation, especially i... more Vernacular architecture employs numerous elements for enhancing natural ventilation, especially in the Mediterranean climate. However, the cooling effectiveness of natural ventilation also relies on occupant behaviour and is highly determined by urban scale attributes. Still, airflow in real, inhomogeneous historic urban settings is rarely integrated in the thermal comfort studies of historic buildings. In this study, a multi-scale approach is adopted in order to assess the role of ventilation in establishing thermal comfort in earthen buildings, in real field conditions. This is achieved by addressing field monitoring of air velocity, temperature and relative humidity in: a) a dense (packing density λp=0.60) and inhomogeneous historic neighbourhood in Nicosia, Cyprus (measurement at a reference height); b) the street-canyon (measured at the mid-height of a narrow canyon with aspect ratio 2); and c) the interior of a typical adobe building with semi-open, pass-through spaces (portico) and closed timber projections with multiple openings, called sachnisi. Building ventilation was addressed as a function of in-street and rooftop airflow. Indoor thermal comfort was assessed in the case of specific ventilation patterns, comparing three adaptive comfort models. The results highlight the complexity of airflow in real inhomogeneous urban canopies and demonstrate that air velocity level in the street canyon is approximately one third of the reference free-stream wind velocity, while indoor air velocity remains at minimum levels. The study also reveals the contribution of night-time ventilation in cooling. Finally, spatial differentials of indoor environmental conditions in the portico were recorded for the first time, demonstrating the role of the sachnisi as a wind-capture element.
The Energy Performance of Hospital Buildings in the South Balkan Region: The Prospects for Zero-Energy Hospitals
Innovative Renewable Energy, 2022
Energy and environmental improvement of built heritage: HBIM simulation-based approach applied to nine Mediterranean case-studies
Building Research & Information , 2023
The architectural engineering and construction sector accounts for about 30-40% of global energy ... more The architectural engineering and construction sector accounts for about 30-40% of global energy consumption. The European goal of reducing this consumption and the linked greenhouse gas emissions calls for an increased capacity to implement building renovations. Building Information Modelling (BIM) and Building Performance Simulations (BPS) are among the most promising tools for fostering interdisciplinary, efficient processes and feasible analysis and design solutions to support this goal. Of the whole building stock, heritage buildings represent the most challenging part, although their potential as a driver for mitigating climate change and supporting sustainable development is being increasingly recognized. This paper presents a Heritage BIM and BPS-based workflow to support the energy and environmental improvement of publicly-owned historical buildings, that was applied to 9 case studies of 7 different Mediterranean countries. The overall aim of this research is to enhance the capacity of public local administrations and professionals to upgrade the historical building stock and demonstrate the scalability of the proposed workflow to the entire building stock of the Mediterranean area.
Lessons Learned from the Development of Massive Open Online Courses on Innovative Strategies for the Rehabilitation of Built Heritage
ICERI proceedings, Nov 1, 2022
Heritage-BIM for energy simulation: a data exchange method for improved interoperability
Building Research & Information, 2024
The use of Building Information Modelling (BIM) for Building Energy Simulation (BES) is challenge... more The use of Building Information Modelling (BIM) for Building Energy Simulation (BES) is challenged by inadequate data integration and unreliable data and geometry conversion. Despite recent efforts to address critical interoperability issues, the effective exchange of data between the two digital environments remains a non-truly fulfilled promise of the digital transformation agenda for the industry. To contribute to the broader community effort in mitigating this deficiency, the present article proposes an alternative method for securing an improved BIM to BES workflow for existing and heritage buildings. The proposed method suggests an alternative way for integrating environmental analysis data to the Heritage BIM model, as well as an easy to develop visual programming process for missing data recovery, through auxiliary exchange operations. The article also presents lessons learned for the geometrical conversion of BIM elements with non-standard and irregular attributes, evaluated through the energy retrofit application of a colonial heritage building. The proposed method demonstrates how visual programming tools and common data exchange formats can supplementary assist existing practises to deal with major interoperability obstacles. The overall findings contribute to current efforts in the field, for the establishment of good practices of using Heritage BIM for energy retrofit architectural interventions.
The Role of the Thermal Mass of Adobe Walls in the Thermal Performance of Vernacular Dwellings
Proc. of the XIIth World Congress of Eastern Architectures, 2018
Renewable Energy and Environmental Sustainability
Safeguarding affordable and energy-efficient medical services has emerged as a crucial necessity ... more Safeguarding affordable and energy-efficient medical services has emerged as a crucial necessity to sustain national healthcare systems, especially in view of the current pandemic. While a set of national standards and guidelines aim to set minimum energy requirements for the building facilities, more insight into the healthcare sector’s energy consumption in Cyprus is deemed necessary, since it is the 4th most energy-demanding sector per square meter in this country. This is the first extended research on energy consumption in healthcare facilities across the different climatic zones of Cyprus and the types of fuel favoured in each zone, which marks the novelty of this work. The findings of the study highlight that the coastal and inland climatic zones are the most energy-challenging regions, with more than 60% of the final energy needs covered by electricity. On the contrary, in the mountainous region, approximately 80% of the final energy needs are covered by oil and attributed m...
Frontiers of Architectural Research, 2021
In this study, the environmental responsiveness of built heritage is closely connected with the a... more In this study, the environmental responsiveness of built heritage is closely connected with the aspects of building typology and urban canyon geometry. The focus of this study is on two-story adobe buildings with lightweight timber projections, locally called sachnisi, which are located on the first floor, above the pass-through space on the ground floor, locally known as portico. The field study reveals and maps a total of 246 sachnisi projections across the walled city of Nicosia, Cyprus, a typical Mediterranean area. This research is the first systematic attempt to integrate cultural, historical, and environmental factors and the urban- and building-scale environmental characteristics of vernacular heritage. The findings highlight thermal adaptive opportunities and passive cooling strategies, i.e., natural ventilation, enhanced by aligning the portico axis with the prime wind direction and operating various openings of the sachnisis. The research also demonstrates that the building orientation and the proportions of sachnisis and porticos are insensitive to the street geometry. Thus, functional and morphological parameters (in addition to climatic parameters) are also significant in the configuration of these architectural elements. The originality and academic contribution of this study lie within the systematic and comprehensive methodology followed, which can be applied to other urban heritage sites. The use of innovative, multidisciplinary methods and tools in heritage studies is also recommended.
Cultural and environmental layers of the urban form: The case of the historic center of Nicosia.
BRAU 04 Conference, Mar 25, 2018
In today’s rapidly changing world, it is crucial to properly document all interrelated values of ... more In today’s rapidly changing world, it is crucial to properly document all interrelated values of cultural heritage expressed through the built environment. In this framework, this study attempts to interpret and relate tangible and intangible expressions of cultural heritage, encrypted in the urban tissue and the building stock of the historic centre of Nicosia. The principal methodological approach is a multi-scale and multi-dimensional reading of the environmental design characteristics on a building, urban and territorial level through the lens of social, economic and historical factors. For this purpose, cross-cultural data are used from travellers’ descriptions, topographical maps, as well as time-lapse air-photographs. In situ observations and climatic indicators are also used. The socio-economic and historical process of defining the urban tissue, the appearance of particular building typologies and the assimilation of morphological elements and particular building techniques, are linked with environmental design parameters. The conclusions acknowledge the inextricable relationship between the social/physical/environmental and climatic factors, and the need for proper documentation so that all interrelated values are considered and preserved through conservation.
The impact of window control on thermal performance. Investigating adaptable interventions in vernacular Mediterranean heritage.
Journal of Architectural Conservation, 2018
The present paper correlates aspects of built heritage conservation, occupant’s behaviour and the... more The present paper correlates aspects of built heritage conservation, occupant’s behaviour and thermal comfort. The research focuses on the contemporary architectural intervention of converting original semi-open spaces, that have been acting as such during all periods of the year, into indoor spaces by adding movable glass dividers. A representative building that reflects the typical arrangement of rural vernacular earth architecture in Cyprus is selected for detailed investigation. In situ measurements and simulation tools are used to investigate the adjustment of airflow through the operation of windows when the dividers are open (heating period) and closed (cooling period). Computational Fluid Dynamics are employed in order to illustrate the temperature distribution of various window operation patterns that are evaluated according to the adaptive thermal comfort. The results argue on the climatic adaptability of vernacular buildings and indicate that the examined window control patterns have a more prominent impact during the heating period. Conclusions confirm the cooling potential of night ventilation and highlight the benefit of having energy-aware and engaged occupants. Key directions regarding conservation practices and occupant’s behaviour are brought forth, bringing energy efficiency and comfort into the discussion about cultural heritage.
The impact of architectural design interventions and occupant interactions on thermal comfort in built vernacular heritage.
The present paper discusses the relationship between built heritage conservation and comfort esta... more The present paper discusses the relationship between built heritage conservation and comfort establishment. The research focuses on the contemporary architectural intervention of converting a semi-open space into an indoor space by adding extended glazed surfaces. A representative building that reflects the typical arrangement of rural vernacular dwellings in Cyprus was selected for detailed investigation. Simulation tools are used in order to investigate the impact of the specific architectural intervention in the semi-open space. Computational fluid dynamics are employed in order to present graphically the temperature distribution of various window-operation patterns that are evaluated according to the adaptive thermal comfort for both the cooling and heating period. The results indicate that occupant behaviour, concerning window operation, affects the overall thermal performance of the building and has a more prominent impact during the heating period. Conclusions highlight key directions regarding conservation practices, taking into consideration the energy efficiency and thermal comfort of the built vernacular heritage.
Thermal performance assessment of vernacular residential semi-open spaces in Mediterranean climate
Indoor and Built Environment, 2017
This paper investigates the overall thermal performance of vernacular buildings in Nicosia, Cypru... more This paper investigates the overall thermal performance of vernacular buildings in Nicosia, Cyprus and highlights the role of semi-open spaces in improving the thermal comfort of the aforementioned structures. The novelty of the study lies in the fact that it presents, in a comparative way, field measurements carried out in five traditional buildings, discussing at the same time the impact of authentic architectural features, as well as of contemporary interventions, on the bioclimatic function of the original building envelope, taking into account the daily use of the premises under investigation. The research outcomes highlight the positive contribution of semi-open spaces to the thermal comfort of vernacular buildings, especially during the cooling period (summer). Contemporary architectural interventions, such as the conversion of semi-open spaces into closed indoor spaces, as well as the behaviour of occupants, are also found to affect the thermal performance of the traditional building envelope.
Adobe walls are considered to be high thermal mass structures, as they have the ability to store ... more Adobe walls are considered to be high thermal mass structures, as they have the ability to store thermal energy. In order to evaluate the thermal inertia of adobes, the delay of the thermal heat wave propagation and the ratio of the reduced temperature of the external to the internal surface are normally investigated; these are expressed by the dynamic indicators of time lag and decrement factor respectively. The present study employs in situ temperature monitoring of a 50 cm thick adobe wall with probes installed at various locations along its thickness. The results are analysed in terms of existing standards and numerical equations. The measured time lag for a period of 24 hours is thus estimated at approximately 5 hours. However, the discussion brings light to the discrepancy between calculated and measured time lag data and raises the issue of evaluating the time lag for massive adobe walls in a longer time range.
Indoor and Built Environment, Dec 10, 2015
This study aims to investigate the natural lighting performance in indoor and semi-open spaces of... more This study aims to investigate the natural lighting performance in indoor and semi-open spaces of urban vernacular architecture in the Mediterranean region. In vernacular architecture, natural lighting was the main source of light available and was largely achieved through the central courtyard. In this framework, an in-depth lighting performance analysis was carried out in a typical and representative traditional urban complex in the walled city of Nicosia, Cyprus. In-situ lighting measurements, as well as software simulations, were employed in order to assess the lighting performance of the building complex. The study has shown that lighting levels of semi-open and indoor spaces on the first floor are sufficient; whereas, the dense urban fabric, and the introverted character of vernacular architecture, create certain limitations to the lighting levels in indoor spaces of the ground floor. On the other hand, the positive impact of the inner courtyard to the lighting levels of semi-open and indoor spaces has been verified.
The Mediterranean climate offers ideal conditions for the exploitation of natural ventilation as ... more The Mediterranean climate offers ideal conditions for the exploitation of natural ventilation as a cooling strategy. However, its effectiveness is highly dependent upon various parameters concerning architectural layout and occupant behaviour. This study provides insight on the way occupants interact with the buildings' elements in order to achieve comfort, focusing on the occupants' behaviour towards vernacular heritage buildings in Nicosia, Cyprus. A questionnaire based survey confirms that ventilation is a major cooling strategy. Further investigation is conducted on window operation patterns through simulation tools. After a thorough analysis of a large number of urban vernacular dwellings, a representative vernacular dwelling located in the urban core of Nicosia was selected as a case study. Its architectural layout reflects the typical arrangement of a two‐storey dwelling with a three‐bay interior arrangement and thus ensures a number of passive design strategies related to natural ventilation. The study explores two types of natural airflow; namely, wind effect, in single‐sided and cross ventilation mode, and stack effect. The impact of daytime, night‐time and all day ventilation is also assessed comparatively. The results indicate that occupant behaviour concerning window operation has significant impact on the overall thermal performance of the building. Finally, the comparative analysis confirms and quantifies the effectiveness of night ventilation as a cooling strategy.
Semi-open spaces are widely used in vernacular architecture across the world. In the Mediterranea... more Semi-open spaces are widely used in vernacular architecture across the world. In the Mediterranean area, they are usually developed along the south side of the building, permitting direct solar gains during the heating period, while providing shading during the cooling period. Thus, semi-open spaces create a protected microclimatic environment that hosts various activities throughout the year. Semi-open spaces constitute one of the main bioclimatic elements of vernacular architecture and, as such, they are worth protecting. However, the built heritage is subject to adaptive interventions in response to social needs. The conversion of semi-open spaces into indoor spaces, with the use of extended glass surfaces, is one of the most commonly applied interventions in rehabilitation and conservation projects in Cyprus, due to the different social needs that they have to meet. However, such actions affect the overall energy performance of the premises substantially. This study provides insight and documentation on the role of south orientated semi-open spaces, as thermal environment modifiers, and highlights the impact of their conversion into indoor spaces. Experimental and simulation tools are used in order to investigate south oriented semi-open spaces encountered in the Mediterranean, focusing on a representative case study that reflects the typical arrangement of rural vernacular dwellings in Cyprus. The results of this research indicate the positive environmental contribution of the semi-open spaces in traditional dwellings as they provide acceptable thermal comfort for a considerable period of time. As far as the conversion of semi-open spaces into indoor spaces is concerned, excessive temperature levels are noticed during the cooling period, in the absence of any shading and natural ventilation, due to the greenhouse effect. On the contrary, during the heating period a positive contribution to the thermal environment of the main building is observed. This can be attributed to the creation of the greenhouse effect and the function of the semi-open space as a thermal buffer zone, reducing heat losses. Conclusions are drawn concerning the proper use and seasonal manipulation by the occupants of the glass openings framed in these spaces, so as to adapt to varying environmental conditions.
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Papers by Stavroula Thravalou