Table of contents

Foreword

From small medieval towns to nineteenth-century boulevards or post-modern concrete structures, buildings reflect our culture and should be preserved for our future generations. In Europe, historic buildings account for a quarter of the existing building stock. Renovating these constructions presents many opportunities for reducing carbon emissions and for improving the comfort of the people living and working inside. However, this can be particularly challenging. Each building is unique and needs specific measures to enhance energy efficiency while preserving historic and aesthetic traits. In this sector, the "one-fits-all" approach hardly applies.

From the 14^th to the 16^th April 2021, the SBE21 Heritage Conference brought together experts working in the fields of energy efficiency and historic building conservation. The conference aimed at fostering multidisciplinary dialogues and finding new affordable and efficient retrofit approaches to save our common heritage and guarantee a sustainable future. Scholars and practitioners worldwide were invited to send their contributions and participate in the debate.

List of Organising committee, Advisory committee, Scientific committee are available in this pdf.

In the framework of the international conference SBE21 Sustainable Built Heritage, a round table was organised to discuss the role of historic buildings in the light of the new European policies recently launched. The European Commission highlighted in a communication related to the European Green Deal that the current renovation rate will need to at least double in order to achieve the EU's energy efficiency and climate objectives. In order to address the enormous energy and resource consumption in the building sector, the Renovation Wave was also launched. When Ursula van der Leyen explained the idea of a New European Bauhaus (NEB), she clearly pointed out the need for a climate-neutral building sector not only as an environmental or economic project, but as a new cultural project for Europe. It is therefore all the more surprising that in all these initiatives the built cultural heritage has not been given any special attention. Reason enough to discuss possible strategies for anchoring the architectural heritage in the EU climate initiatives with the invited panellists of the SBE21 Heritage Round Table. All of them know the current policy making in the framework of the Green Deal from a different perspective – from EU-Level to the local implementation, from research to practice. The invitation to the round table was accepted by:

All papers published in this volume of IOP Conference Series: Earth and Environmental Science have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

• Type of peer review: Double-blind

• Conference submission management system: Ungerboeck

• Number of submissions received:

○Abstracts: 86

○Full paper: 61

• Number of submissions sent for review:

○Abstracts: 86 o Full paper: 61

• Number of submissions accepted:

○Abstracts: 84

○Full paper: 57

• Acceptance Rate (Number of Submissions Accepted / Number of Submissions Received X 100):

○Abstracts: 97,7%

○Full paper: 93,4%

• Average number of reviews per paper: 2

• Total number of reviewers involved: 42

• Contact person for queries:

• Alexandra Troi

Alexandra.troi@eurac.edu

Vice Head of Institute

Institute for Renewable Energy

Eurac Research, Bolzano (Italy)

• Daniel Herrera

Daniel.herrera@eurac.edu

Senior researcher

Institute for Renewable Energy

Eurac Research, Bolzano (Italy)

The renovation of historic buildings (regardless of their preservation status) has an overarching socioeconomic impact that goes beyond the environmental or economic benefits. These benefits can be seen as public goods. Within the ATLAS project, a survey covering over 35 rural alpine municipalities was launched to gather information about the municipalities' motivation and interest in renovating their heritage building stock based on its contribution to local economy, social and environmental aspects. Moreover, the research inquired on how the municipalities define their role in the renovation process and the obstacles they face. This paper provides a summary of survey results with the aim to contribute to the understanding of the underlying considerations of rural municipalities in the Alpine region when renovating their historic building stock.

Renovations, especially of historical buildings worthy of preservation, often present the clients with seemingly unsolvable tasks, be it conceptual, organizational or financial. However, historical buildings built before 1919 account for between 20-30% of the existing stock in the rural regions of Vorarlberg, which means that there is considerable potential [1]. In our experience, it makes sense to differentiate between technical and creative renovation consulting when providing assistance in the run-up to a renovation. In the reorganization BEFORE consultation above all the question is urgent, which possibilities are in the building and which financial loads with which reorganization variant come to the owners, because the owners of house often lack the creativity and experience, in order to come even on a suitable variant. In a pilot project, the Energy Institute Vorarlberg in cooperation with 12 external architects, the so-called renovation pilots, has now completed over 30 such consultation cases since January 2019, and more are in the works. The refurbishment PRE-consultations of the first one and a half years have shown that about one third of all consulting cases revolve around houses that are in some way worthy of historical preservation. In order to take into account the special features of these buildings, especially with regard to their energy efficiency, this topic is taught in greater depth to renovation pilots in a training module and a brochure within the framework of the Interreg Alpine Space Project ATLAS¹ [2].

The implementation of RES technologies in preserved areas encounters specific challenges and barriers due to the pre-existence of valuable heritage and natural values. This research aims at identifying a clear methodology to evaluate the potential application of Building Integrated Photovoltaics systems (BIPV) in heritage buildings and protected land areas. The study, realized in the framework of the Interreg V-A Italy-Switzerland project "BIPV meets history", presents the methodology for analyzing the best BIPV exploitation possibilities to validate their applicability in a preserved land area in the province of Como (Italy). This methodology considered several characteristics such as the predisposition, limits, suitable BIPV technologies and so forth. After the identification of the most recurrent building types and the related relevant characteristics for the solar potential exploitation have been identified, the analysis focused on the historical buildings that despite the high energy retrofitting potential encounter the major technical and heritage constraints for BIPV. The study resulted into a building classification database, which lists a series of parameters and identifies the main architectural elements and compatible criteria with the BIPV application. This study creates the base for the evaluation of effective energy savings related to the use of BIPV technology on heritage buildings and landscapes and demonstrate their potential for improving the energy efficiency of historic buildings and sites, safeguarding their heritage values.

The recovery of building heritage through the containment of carbon emissions is one of the strategies pursued by the city of Palermo. This design approach becomes more paradigmatic when it's referred to sensitive and historic buildings or urban areas, having an international interest or involved in participatory projects for the Mediterranean city, well beyond the attention that citizens attest to them. We would analyse the Volta electrical Power Station, inside the harbour area and near the Castello a mare, interested by the overall rehabilitation of Palermo waterfront. This building qualify itself, through a retrofit hypothesis proposed by the authors of this essay, as a significant example of rehabilitation design, capable to respect memory but also to propose an improvement of energy performance, through a compatible and technological implementation that use information technology in order to verify passive strategies for internal environmental comfort, an improvement of healthiness and quality of confined environments through high-tech plant engineering choices. The results of this study is a design proposal of a system of openings and an evaporative cooling, contributing to lower the internal temperature during summer.

Venice is known for its history and beauty and its fragility and potential demise. The city is experiencing an increase in yearly average temperatures affecting outdoor - indoor comfort and average energy expenditure. Owing to existing literature demonstrating how local microclimate depends on urban density, shape, and orientation of buildings and materials, the work studies the influence of changing Venice temperatures by targeting such issues, focusing on an urban fabric typical form, known as Campi. Based on IPCC's future weather predictions for 2050 scenario A1B, the work highlights how the urban fabric configuration affects the local microclimate and outdoor conditions to define how buildings will mitigate and adapt to environmental transitions. The method couples microclimate and outdoor comfort users' perception of Physiological Equivalent Temperature (PET), via ENVI-met. Preliminary results show that the compactness of the urban fabric in Venetian Campi significantly reduces outdoor temperatures due to the increased density of shadow areas in the courtyard or in narrow Venice streets. The role of water is also simulated via ENVI-met, as buildings' materials and indoor energy consumption are assumed as invariant to evaluate the historic urban fabric climate resilience. The results constitute a first step towards understanding to what extent a particular urban fabric type is thermally resilient.

Nowadays the proper use of energy towards ever major energy efficiency is a topical issue also for heritage buildings (hereinafter HB) which have special value both as a material testimony of our past and as a cultural asset. Greater open-mindedness to find compatible integrated solutions to improve the sustainable use of our built heritage is growing which consider, not only revamping the structural integrity, the indoor air quality and user comfort, even appraise benefits on using innovative materials or construction techniques to increase energy efficiency and exploit renewable and solar energies. Technological advances in Building-Integrated Photovoltaics (BIPV), hybrid photovoltaic thermal systems in combination with other renewable resources can be used as support for other smart measures applied to the historic building envelop, windows or the HVAC and ventilation systems. Main findings based on documented examples of best practices clearly demonstrate the maturity of these solutions and will be presented. This study in Switzerland in the framework of two Interreg projects allowed to collect documentation on case-studies with a high standard energy concept, from net zero energy (NZEB) to positive energy buildings (PEB), which demonstrate how solar BIPV technologies can be well-integrated to enhance energy efficiency in historic buildings

Within the framework of ATLAS research project (Interreg Alpine Space Programme 2014-2020. ID: ASP644) experts of different countries of the Alpine arc studied and compared the measures implemented in the various countries to strengthen and further promote the implementation of renewable energies at the local level. This study highlights those strategies and existing tools for potential assessment of renewables taking into account the applicability for historic buildings, pointing out similarities and differences as model reference between the different territorial areas. The work aims to disseminate and capitalize on the best practical experiences on the topic, and to engage as many stakeholders as possible for a wider implementation of renewable energies in the territory of the Alpine arc. Direct examples of implementation at regional and local level to exploit RES while preserving the authenticity of historic buildings and settlements to be protected in the different countries and regional areas of Alpine Region are shown exploiting their full potential with practical advice for model regions.

Detailed construction analysis is essential to the compatible energy improvement of historic buildings. In-situ measurements are crucial for energy diagnosis but their use is limited, especially in vernacular architecture. This paper exposes the development of a hygrothermal and mechanical database for Sicilian historic walls. The proposed method, applied to eleven historic centres, is based on the investigation of those masonry construction features, which recur in local contexts. Preliminary results concern the case study of Petralia Sottana, where a first set of laboratory measurements of stone compressive strength and thermal conductivity was conducted, together with in-situ tests of masonry thermal conductance. Focused on stone walls, these results are used to discuss potentialities and limits of the proposed categorisation of traditional masonry as a support to the energy diagnosis of historic buildings.

The study examines the sustainability of a restored historical building – Baron Empain Palace in Heliopolis, Cairo in terms of its environmental, social, and economic aspects as well as cultural impacts. It assesses how the restoration of a deserted palace brings about a sustainable and cultural node, yet transforms the landscape use and sustains the district's heritage. Two approaches were exploited to assess the historical building: the first approach is inductive (review of the case study before and after restoration, its impacts on livability); and second is a field approach based on site visits to collect data on the environmental and energy consumption (energy audit); social sustainability (visitors' patterns); and economic sustainability (jobs opportunity). Results revealed that the social and cultural values prioritized and the youth represents 71% of the visitors/hr during COVID-19. The environmental and energy audit assessment shows that the restoration met RIBA's energy efficiency benchmark (50kWh/m² (good) and 70kWh/m² (typical)). For the economic sustainability, tickets are affordable and the palace creates 38 jobs. The social media analysis indicates a high interaction. The restored palace is a unique example of adhering to the city's cultural values. Finally, it shows the significance for historical palace transformation on the community.

Today, it seems that talking about the existing traditional buildings is a somewhat elegiac vision in the face of the magnitude of the global changes that are currently taking place, yet it is a truism to repeat that without this, the city would lose its anchorage and its identity; as a result, and so that it can move at the same rhythm of the changes that are continually reshaping its physiology, it seems urgent today to reconcile energy performance with the architectural qualities of its built environment. The present work aims at reducing the pressure on the environment by intervening on a heritage hotel building located in Central Algiers through a comparative LCA with a low consumption hotel building in France, in order to reduce its generation of environmental impacts, particularly carbon dioxide, while identifying the contribution of the main sources to the overall balance and thus know which elements of this building require special attention in the effort to reduce the impacts generated for a possible renovation. This objective was achieved by a double evaluation, one energetic and the other environmental by LCA which enabled us to develop a new variant emitting 60% less CO2 while preserving the heritage qualities of our building.

The European built heritage is strongly characterized by "historic buildings". This built heritage represents an important cultural resource, constitutes a public good and testifies the community identity. The current challenge to reduce the consumption of energy resources is aimed at the requalification of this built heritage. To meet this challenge, energy analysis is increasingly being used also for historic buildings through complex building energy simulation program. Although their application to modern buildings leads to significant results, in the modelling of historic buildings there are numerous approximations and uncertainties relating to materials, thermal bridge, geometry and construction techniques which can lead to inaccurate results. Furthermore, the lack of input data and the complex geometries make even more difficult to determine the correct energy performance of the simulated built heritage. To the aim of investigates the validity, accuracy and reliability of Open BIM software, widely used by Architects and Engineers, based on the simple hourly method (EN ISO 52016-1), an energy analysis of historic building was performed. The work is intended to provide a calculation method to evaluate energy performance (heating, cooling, lighting, etc) of historic buildings (load bearing masonry structure with vaults) with the use of simple dynamic models, which comply with Italian energy laws and regulations, and to predict the energy saving potentials related to building retrofit actions.

POCITYF - a H2020 smart-city project - supports cities with historical and cultural heritage districts, by developing innovative solutions and technologies to be applicable in cities with an architecture characterized by historic and/or cultural protected buildings and districts. To harmonise the innovative solutions with cultural heritage, the inclusion of relevant stakeholders' opinions in decision-making and implementation of the project is crucial, as stakeholders are not only affected by the solutions, but also influence their successful implementation. To identify their needs and interests in relation with the list of innovations proposed, three (3) types of surveys were carried out among different stakeholder groups: Impact & Readiness of the solutions; Power & Interest of the local Stakeholders; Citizens' Knowledge & Acceptance of the solutions. These surveys facilitate the selection, deployment and replication of the smart city solutions as well as strategies for social engagement, ensuring they are appropriate for the cultural heritage of cities and its citizens' requirements.

Balancing conservation of historic buildings and improvement of their energy performance is a challenging task that involves multiple factors. Prescriptive standards for interventions of internal insulation in modern materials are not compatible with conservation of historic plasters and thus a more detailed and sympathetic approach must be used. Knowing the hygric behaviour of historic plasters is a prerequisite in the assessment of any intervention of internal insulation. In this paper, four different methods for the quantification of the water absorption coefficient, laboratory and onsite based, are presented and applied to an outstanding case study in Tyrol (AT). The variability observed, between methods but also between the different layers of plasters found onsite and even between measurements, highlighted the need for robust guidelines for the application and interpretation of the results. This study summarises the numerous factors influencing the result of the water absorption measurement and shows a first investigation into one of these aspects (heterogeneity of the wall). Numerical simulation has proven to be an effective tool to use in combination with experimental results in testing the effect of the different parameters affecting the water absorption characterisation of historic plasters.

This study presents a conceptual vision of an innovative approach to refurbishing the vacant urban spaces and abandoned buildings of the former SIAPA area in Galliera – Bologna, Italy, transforming it into a liveable, productive, and sustainable park through applying the recent technologies in urban farming. The methodology depends on two approaches: an assessment of the current site and an applied study incorporating technologies that are based on soilless solutions to reduce the consumption of irrigation water, wastes, and increase production. The upgraded park named "Galliera Kitchen Park" (GKP) integrates urban farming technologies for the outdoor farms, whereas, the vertical zip-grow technologies are exploited in indoor farms, generating fresh kitchen crops. GKP works on linking the industrial area with the residential area as well as connecting citizens to vibrant places where food and memories are derived from. A business plan includes marketing strategy, operation management, SWOT, financial analysis, and a business model study to predict the worst-case and best-case scenarios for the project running. Finally, requalifying the area would benefit back the entire town; it could be once again an economic centre for Galliera. The results highlight the potential of the proposed intervention to attain SDG 4, 7, 8, 11, 12, 13 and 17.

Many of the recovery and renovation interventions of the existing heritage conducted today in Europe are the result of urban policies careful to reduce land consumption and improve safety, comfort, and quality according to the needs of users. A substantial historical building heritage characterizes the Italian territory. Historical centres' regeneration is one of the constant and recurring themes of extreme complexity and importance due to the extension, the peculiarities, and the conformation in some cities. The contribution presented deals with the redevelopment and reactivation of a historic district of Genoa, which has one of the largest historical centres in Europe. Innovation, together with the three pillars of sustainability (environmental, social, and economic), are the engines of this pilot project to trigger virtuous processes for the district's reactivation. It is an area of the historic centre with high potential in its proximity to essential activities of the city, the port, and infrastructure. The proposed plan for the regeneration of the area resulted from an in-depth analysis of the territory's state and existing practices and was carried out in close collaboration with the reference bodies and actors involved. This preliminary analysis made it possible to identify the strengths and weaknesses that were the starting point for the pilot project. The article then focuses on two specific aspects. Some of the university's buildings are in the district, and this is the starting strength for creating a "diffuse" university campus with areas to serve students. On the other hand, the open spaces are the point of weakness on which we have worked with outdoor lighting to increase the degree of security of the neighbourhood and enhance the peculiarities and value of existing spaces.

Energy retrofit of historic buildings often represents a challenge for owners and practitioners due to the lack of knowledge and access to suitable solutions. The growth of awareness and interest in sustainability has caused an increase in the number of solutions available for improvement of historic buildings' energy performance. What it is still missing is their dissemination across the involved stakeholders. This will improve practitioners' trust on these solutions and the adoption by owners in the building renovation. In the framework of IEA SHC Task 59 and the Interreg project ATLAS, experts have collected well established and innovative solutions for historic building renovation presented in an online decision guidance tool. The set of solutions is structured in four groups: wall insulation, window solutions, solar systems and HVAC systems. For each group a decision tree was developed to guide the end-user with questions to the appropriate solutions for their building. The tool aims to inspire and motivate technicians and owners with a large number of possible solutions, which serve as a basis for further investigation and planning. With more than 130 documented solutions it is already a comprehensive tool that can be used as basis and extended in future.

The energy refurbishment of historic buildings is necessary for many reasons, for the preservation and continued use of the buildings themselves, but also to achieve a very much needed reduction of GHG emissions. Good examples of such refurbishments show that the conflicting demands between respecting and protecting the heritage significance and achieving high levels of energy efficiency can be met. The case studies documented in the Historic Building Atlas HiBERatlas are used to examine which influencing factors are responsible for the success. This database is one of the main outcomes of the research projects Interreg AS ATLAS and IEA SHC Task 59 to provide a solid knowledge base on deep renovation of historic buildings and includes so far a broad range of about 50 different case studies published. The case studies presented here as examples were carried out under different framework conditions: as part of a research project, with public financial support or with a committed and experienced planning team operating in an integrated design process. It will be assessed how professional preliminary research, ambitious objectives, and the access to technical solutions can affect the results. Finally, the paper will highlight findings of post occupancy evaluations and lessons learned.

The widespread of photovoltaic (PV) technology has led to high-performance products and systems during recent years. This allowed an expansion of PV application scope enormously, especially in listed buildings and natural landscapes subject to different forms of protection. Despite that, there are still many doubts and supposed limitations regarding their applicability by stakeholders involved in the construction process. Best practices and applications help to spread the applicability of the PV technology in historic buildings, conservation areas and cultural landscapes. For this purpose, the "Special Award for Solar Architecture in Heritage Contexts" developed within the framework of the Interreg project "BIPV meets history" aims at awarding the more significant Italian-Swiss BIPV case studies in historical buildings and heritage landscapes. This research work offers an overview of the 85 projects nominated for the award. The best projects are described and analysed to define the state of the art and criteria and technologies used for PV integration in architecturally sensitive areas to raise awareness to all stakeholders involved. The trade-off between cutting-edge technology and design expertise can lead to the perfect balance between historic buildings or high-value contexts preservation and contemporary needs and lifestyles.

Research into building-physics in the UK over the last 15 years has demonstrated the significant constraints to the extent to which the energy efficiency of historic buildings can sensibly be improved. While some of these include risk to character and heritage significance, others are linked to moisture movement, mould growth and the comfort of building fabric and users. In parallel with this research and project work, the UK has signed the Paris Accord and committed to delivering zero-carbon by 2050. Although there may be alternative sources of energy, such as hydrogen, to deliver the decarbonisation of industry and transport it seems unlikely that these will make a significant contribution to the decarbonisation of building energy use. In these circumstances electricity will be the sole zero-carbon energy supply for the heating, ventilation and lighting of all existing and new buildings. This dependence suggests that any supply-side limitations on the energy available will inform or impose a requirement for improved performance and thus on the scale and nature of retrofit measures required to each building. This paper establishes potential energy allowances for existing residential buildings from the published future energy supply scenarios and cross references these with the existing metrics for retrofit and with the available post-occupancy performance data on completed retrofit projects for historic residential buildings. This analysis provides an indication of the nature and extent of the level of retrofit that will be required to existing buildings in order for the UK to deliver on its zero-carbon commitment and suggests the kind of approach and methodology that should be adopted for retrofit in order to avoid the fabric risks identified above.

This study examines compatibility of monument conservation and modernization of historic windows of old buildings on the example of the Alte Schäfflerei (Old Cooperage) housing the Fraunhofer Centre for Conservation and Energy Performance of Historic Buildings at Benediktbeuern monastery. Several historic windows are extended to box-type windows and examined in detail. The calculation of the thermal bridges and the resulting U-values of the windows as well as the linear thermal bridge heat loss coefficients result in a reliable estimation of the thermal behaviour of the box-type windows. Via measurements of the surface temperature and heat fluxes on a box-type window the thermal resistance and heat transfer coefficient are estimated. The heat transfer coefficient is calculated in accordance to DIN 10077 with simple and detailed calculation and compared to the estimated calculation of simplified measurements. The energy efficiency of the whole building of the Old Cooperage is calculated in accordance to DIN V 18599 and shows the rate of heat losses of the windows compared to the overall energy demand of the building. For this purpose, the Old Cooperage is implemented with a hypothetical historic usage in DIN V 18599.

Natural and cultural heritage are important resources for engaging local communities in the promotion of a sustainable future, both for achieving energy targets and repopulating rural areas. Public engagement is an important factor particularly to preserve historic rural buildings and its landscapes in Alpine communities, where people build up an emotional relationship with cultural and natural heritage. The study, realised in the framework of the Interreg ITA-AUT SHELTER project, aims at defining a new use for an abandoned historical building by the engagement of the local community and, according to the new use, at defining insights for elaborating the energy retrofit balancing preservation and sustainability issues. The study also identifies the relevant elements to be available within a local community to ensure a long-lasting use and management of a public retrofitted historical building. Among these elements and using the sociological lens, we investigate: the materiality of the historic building and its landscape; the community and social meanings attributed to the building and the landscape; and the heritage management competences of the local community to manage and maintain the building in the next future. All these elements can be translated into a social practice of building and land management that avoids a second abandonment. Social science-based interviews are conducted in Valbrenta (IT), using content analysis.

Historic libraries preserve cultural heritage values while housing rare manuscripts and paper-based collections. The collections in the libraries are deteriorated chemically, biologically and mechanically due to inappropriate indoor environment conditions such as temperature and relative humidity fluctuations and microbiological conditions. Apart from preserving vulnerable paper-based collections, accommodating of a considerable thermal comfort level for visitors is essential in historic libraries. The aim of this study is to analyse indoor environment of a historic library in terms of thermal comfort and preventive conservation of paper-based collections. Izmir National Library, built in 1933, is selected as a case study. Indoor air temperature, relative humidity and air velocity in the library were monitored with a one-year measurement campaign. Meanwhile, thermal comfort of the visitors was assessed with PMV/PPD indices and thermal sensation surveys. The results show that high chemical degradation risk is detected in the library while biological and mechanical degradations are in the low risk zone. On the other hand, 87% and 93% of the visitors feel thermally satisfied in heating and cooling seasons, respectively.

The text briefly traces the educational objectives and methodologies adopted in a highly specialized course (post-Master programme) which for years has trained specialists in the field of conservation and restoration of the architectural monumental heritage, with particular attention to the improvement of energy efficiency and to the inclusion of devices powered by renewable energy sources, while preserving the main role of education in architectural and material conservation. It is quite a 'pioneering' experience, compared to its frame of reference, based on the mutual consideration of different specialisms and on an interdisciplinary concept of the work (by sharing objectives and languages by experts in scientific sciences and human sciences implement their own methodologies to achieve a common purpose). Further increased with research opportunities at national and international level, these experiences have led to an awareness of the key players in the process of conservation, a high-level training of technical specialists and to some valuable experiences, currently underway.

The paper will show a real case project that has been retrofitted in a sustainable and energy efficient way to promote sustainable development in rural areas. The historical farm house "H14" (built up in 1858 and located in North Bavaria) is a typical Franconian three-sided building. The building has been vacant for over 30 years and the renovation was founded by the Bavarian Federal Office for the Preservation of Monuments and Historical Buildings. The paper will give an overview about the retrofit of the historical farm house into a two-family house with event and seminar rooms and its integration into the rural environment. The renovation concept pursued the following goals: low carbon retrofit and renewable energy solutions, resource efficiency, use of existing, historic and renewable building materials, life-cycle costs, buildings physics as well as integrating regional flora and fauna.

Energy retrofitting standards and guidelines, together with benefitting from best existing experiences, are effective in retrofitting heritage buildings towards low-carbon emissions. In Downtown Cairo, many heritage buildings are exposed to adaptive reuse practices, after moving to the 'New Administrative Capital'. Integrating energy saving in said practices has become a crucial aspect. Therefore, the aim of this study is to evaluate a recent retrofitted heritage building called 'La Viennoise' as an example of best practice for retrofitting processes in Downtown Cairo. The study carried out a field survey for data gathering. A monitoring-based simulation model was created and calibrated, and the building envelope and energy use were evaluated. The simulation results are presented into two cases. The first includes the original state as a base case, showing a very low building envelope thermal performance. The second includes the current state as an improved case. A comparison of both cases shows that the implemented retrofitting scenarios in the case study effectively improved its building envelope and reduced annual energy consumption, and CO₂ emissions. This paper allows further benefit from such example by setting a retrofitting guideline to expand this concept in other buildings with similar conditions to achieve a low carbon-built heritage.

The housing and service sector account for nearly 40 percent of the total energy usage in the European Union (EU). Improving energy efficiency in the building stock is therefore of vital importance to ensure climate goals. However, increasing the energy efficiency of existing buildings can lead to conflicts with other sustainability goals, such as the preservation of cultural heritage values of the built environment. How this conflict is handled in practice will depend on the design of the legislation and ultimately, the legal system. Not only is legislation on the protection of cultural values necessary, the legal system as a whole must be coherent and without deficits, loop-holes and conflicts contradicting goal fulfilment. Moreover, the norms must be effectively applied and complied with. Results of an interdisciplinary research project assessing the effectiveness of the Swedish legal system in reaching energy goals while preserving heritage values, show that meeting sustainability goals are jeopardized by not applying the law in accordance with the intent of the legislator. This paper elaborates on the deficits identified and how they can be improved in order to handle sustainability conflicts.

This paper investigates how societal goals of heritage conservation and energy efficiency are handled in the management of Swedish multi-residential buildings. Interviews were made with larger owners of multi-residential stocks, and their perspectives are compared to officials at the City Planning Offices in two Swedish municipalities: Göteborg and Gotland. The questions posed are: How is heritage prioritised in relation to increased energy efficiency, climate impact and other objectives such as cost-efficiency? How important are their internal policies in comparison with external policies imposed by society? The companies express that they are proud of the heritage of their building stock, but they have not integrated heritage values in their management plans and strategies. Social issues such as safety and well-being are included, but not heritage. A consequence of this lack of systematic consideration of heritage is that measures for increased energy efficiency may conflict with conservation needs. In order for heritage values to be taken more seriously in relation to energy efficiency they would need to be integrated into such plans. The benefit from integrating heritage values in sustainable housing management is a question that should be further studied. The paper refers to SDGs 3, 11 and 13.

This paper presents a novel heating system for churches based on a combination of an air-to-air heat pump for conservation and bench heating and overhead radiators for comfort heating. The heating system was implemented in a church in southern Sweden. Initial assessments showed that this type of heating system could provide an acceptable comfort for visitors with a significantly reduced energy and power demand. At the same time preservation conditions improved. A second assessment, ten years after the installation, showed that the performance was not as good expected. This was partly due to leaving the intended mode of operation, partly due to a need for technical adjustments. To meet future challenges the rural churches in Sweden need affordable heating solutions both for conservation and comfort. The proposed heating system is a step in that direction but further technical refinement as needed as well better user support to manage a new and more complex type of heating system.

The European project Adapt Northern Heritage (2017-2020) was supporting northern communities to adapt historic places to the environmental impacts of climate change through community engagement and informed conservation planning. A risk management toolkit was developed to help stakeholders, caring for historic buildings and other places of the historic environment, to better understand climate hazards, impacts and risks and utilise this knowledge to commence the process of strategic adaptation planning. This paper focuses on the project's stakeholder engagement to develop and disseminate the toolkit: Firstly, workshops were held at the project's nine case study sites in Iceland, Ireland, Norway, Russia, Scotland and Sweden. Secondly, the structure of the workshops was compressed and simplified into training seminars, held in Greenland, Ireland, Northern Ireland and Scotland. Finally, digital modules for continued learning were created. The toolkit and digital modules remain freely available online. This paper discusses the workshop's engagement concept, structure and techniques and how they were developed and utilised for the seminars and modules. The paper draws conclusions from this process and reflects on its transferability to related fields of activities, such as using stakeholder engagement to improve the carbon / energy performance or sustainability of historic buildings.

Improving the energy efficiency of traditional buildings, which represent a large proportion of the building stock in the UK, is necessary to meet national targets on greenhouse gas emissions and alleviate fuel poverty. Traditional dwellings in the UK are defined as hard-to-treat homes because insulating them is not cost-effective or might lead to moisture-related issues. This has led to efforts from policy-makers and organisations towards minimizing moisture risk in the energy-efficient retrofit of traditional buildings. This paper presents an overview of the work done towards a moisture-safe retrofit in the UK in the past ten years, focusing on the Government's policies and the work and legacy of the late Neil May, one of the pioneers in sustainable traditional buildings in the UK.

Historic buildings have been gradually considered within energy efficiency practices and renewable energy systems, but the implementation of such measures is more complex for historic buildings. It is fundamental to understand the importance of users in the heritage-energy sector. Thus, energy conservation practices of historic buildings that involve less invasive interventions that could lead to loss of value must be promoted. The paper illustrates how residents of historic buildings in the Historic Centre of Mexico City (World Heritage) make decisions on energy efficiency with the ultimate goal of improving thermal comfort and reducing energy consumption. This study consists of five in-depth semi-structured interviews complemented by monitoring internal environmental conditions such as temperature and relative humidity. The thematic analysis of the interviews was followed by a system dynamics analysis to better understand the changes in decision making over time. The dynamic hypothesis is that heritage values assigned to historic buildings change over time and they drive or prohibit changes in energy efficiency. Moreover, a tension arises over time between the limitations on listed buildings in which making many changes in use and energy efficiency interventions is prevented. Our results show that participants take passive thermal-comfort actions (e.g., wearing more clothes and closing windows) when internal temperatures are low. They oppose major interventions or invasive retrofitting to the building, given the high cost and potential loss of value assigned to their buildings. The changes the users would consider while dealing with uncomfortable internal conditions are small interventions in floors and ceilings; however, they avoid making changes to aspects they consider are important and must be preserved and protected (social and cultural values). Integrating the understanding of users' behaviours toward energy efficiency and heritage values can enhance retrofitting policies and guidelines that help protect and maintain the heritage-built stock.

Having tomorrow's architects energized at retrofitting historic buildings might be decisive for bringing towards zero our building stock's carbon emissions while maintaining the values of historic buildings and city centres. To reach this aim, the authors worked with the recently developed Historic Building Energy Retrofit Atlas (www.hiberatlas.com) in an elective course at the faculty of design in Coburg/Germany for architecture and interior design bachelor students as well as students of the master Heritage Design. The HiBERatlas presents best practice examples starting from a description of the building's architecture and heritage values, presenting the overall aim and concept of the retrofit project, only after that explaining the single retrofit solutions and closing with some key figures on the performance. All this supported by photos and drawings which illustrate the single aspects. Since this structure reflects also the good practice in retrofit design, it seemed suitable also for teaching students how to handle the energy retrofit of a historic building: By documenting good case studies, which had been awarded for their ambitious energetic renovation, students gain deep insight into the architectural design and technical implementation. An excursion to the buildings with contact to the architects and building owners was an important part of the course, since the face-to-face meetings with the – often very engaged and enthusiastic – building owners helped understand the reasons behind decisions. The wish of students to however get at the beginning a clear guidance on "what should be done" when retrofitting historic buildings, was addressed in the second editions of the course with a bit more theoretic input in the early classes, but at the same time the clear message, that there are no "one fits all" solutions for the retrofit of historic buildings.

This paper describes the work undertaken within the international project IEA SHC Task 59 Renovating Historic Buildings Towards Zero Energy to produce a handbook for the planning of energy retrofits in historic buildings. The handbook is an attempt to increase use and usability of the European standard EN 16883:2017 - Conservation of cultural heritage -Guidelines for improving the energy performance of historic buildings. The standard provides a decision roadmap for how energy efficiency measures can be identified that both respect the heritage values of the building and improves the energy performance. It also provides general information about energy efficiency in historic buildings. There has been a lot of interest in this standard from researchers in the field of energy efficiency in historic buildings, but it has not been widely used in practice. The first part of the paper summarises an assessment of the use, or lack thereof, of the standard. The assessment is based on nine European case studies that identify how the European standard can be complemented with additional resources, examples and guidance. In the second part the work with a handbook complementing the standard is outlined, and recommendations to future revisions of the standard are suggested.

The 145 year old rural case building presented in this paper has undergone a deep renovation including internal insulation of the external walls to reduce the heat loss and improve the indoor thermal comfort. The internal insulation was a PUR-based insulation with channels of calcium silicate, experiencing to some extent capillary active behaviour. Sensors were installed between the existing wall and the internal insulation to monitor the development of hygrothermal conditions. The external façade was later hydrophobized with a water repellent agent to minimize the wind driven rain load. Measurements show that it takes time to get rid of the built-in moisture due to the application of internal insulation, however the moisture content expressed in relative humidity is slowly decreasing, although still high about two years after hydrophobizing the wall. Simulations show that the order of hydrophobizing the wall and applying internal insulation is important to promote drying of the wall.

This paper will focus on three topics regarding sustainability and heritage. It reflects on the effects on the long-term maintenance and improvement of heritage buildings through energy-efficient interventions. It also addresses how the mindful use of resources and energy in the refurbishment of historic buildings can contribute towards the preservation of finite resources and the environment for future generations. Furthermore, the current state-of-the-art in long-term preservation, aided by new data collected through digital technologies in heritage conservation is discussed. The paper concludes with the presentation of a new Masters' programme in Digital Technologies in Heritage Conservation and its development, and poses the question can an efficient knowledge transfer to future stakeholders by higher education be achieved in order to further the development in sustainability and gain new impulses in the responsibility for cultural heritage.

This paper gives an introduction into the research and measures of monument conservation and energy performance improvement of the Alte Schäfflerei (Old Cooperage) in the monastery of Benediktbeuern in upper Bavaria, Germany. The works started in 2010 when a contract was made between the Monastery and the Fraunhofer Gesellschaft to establish the "Fraunhofer Centre for Conservation and Energy Performance of Historic Buildings". Both, resource and energy efficiency are approaches that are in the focus of the research. Moreover, all measures should comply with monument preservation rules and respect the original substance. The calculation of the impact of different energy saving measures like the improvement of the historic windows, internal and external wall insulation, attic and floor insulation as well as the use of renewable energies from the central power station of the monastery on the overall energy demand is presented.

Mercado del Val is an iron market located within the old town of Valladolid, Spain, whose construction was completed in 1882, being currently the oldest preserved market in the city. During the period 2013 – 2017, the market was part of a FP7 European demonstration project, called CommONEnergy (Re-conceptualize shopping malls from consumerism to energy conservation) under grant agreement n° 608678, focused on the rehabilitation and energy efficiency improvement of shopping centres. The CommONEnergy project focused on improving the energy efficiency of the market was part of a new integral refurbishment project already planned for the market in 2013. Before the rehabilitation project of 2013, the market presented a decaying appearance. From 2013, the market was fully renovated by recovering a building representative of the architectural and commercial activity of the late 19^th century, being respectful of its essence, but transforming it into an innovative building that responds to the commercial needs and potential of the 21^st century. The inclusion of the market in the European project made possible to improve the building's energy performance and indoor environmental conditions together with the satisfaction of vendors and customers.

This paper presents a reproducible framework for the energy refurbishment of existing buildings. It is constituted by the CasaClima R protocol, a certification procedure described by the "Technical Directive CasaClima R" and aimed at exploiting the energy potential of buildings on a case-by-case basis. Some verification tools support the protocol in order to avoid errors occurring during the planning and construction phase, that could lead to damages of the building´s substance and could cause problems to the health and well-being of the occupants. The implementation and application methods of all framework components and possible future developments will be described, considering the great wealth of historical buildings in Italy and Europe and the great potential for energy savings that can be achieved.

Historic and heritage buildings present a significant challenge when it comes to reducing energy consumption to mitigate climate change. These buildings need careful renovation and increasing their energy efficiency is often associated with a high level of complexity, since consideration for heritage values can often reduce and impede possibilities and sometimes even rule out certain improvements completely. Despite these issues, many such renovation projects have already been carried out, and therefore the IEA SHC Task 59 project (Renovating Historic Buildings Towards Zero Energy) in cooperation with Interreg Alpine Space ATLAS has developed a tool for sharing these best-practice examples – the HiBERatlas (Historical Building Energy Retrofit Atlas). The Internet platform serves as a best-practice database of both individual energy efficiency measures and whole-building renovation projects. This paper presents two of the Danish projects featured in HiBERatlas. The first project, Ryesgade 30, is a Copenhagen apartment building with a preservation worthy period brick façade. The second project is the Osram Building, a listed Copenhagen office building from 1959 with a protected façade, which today acts as a culture centre. Both renovation projects achieved significant energy savings and consequently CO₂-emission reductions, and the indoor climate in both buildings have also improved significantly.

Balancing the needs of building conservation and carbon reduction, whilst often considered a challenge, it can also be an opportunity. This paper will start by outlining some refurbishment principles that have been followed by Historic Environment Scotland in a conservation-based approach to the refurbishment of traditional buildings. The principles develop themes in building conservation and retrofit discussed by Historic Environment Scotland and other heritage organisations and add in more recent thinking on resources, embodied carbon, the circular economy and climate change to give what might be called a 'multifactored approach'. These factors or considerations are not new in heritage work but are not often considered in mainstream, less conservation focussed refurbishment projects. These factors go beyond issues of heritage conservation alone and allow the experience and findings of conservation sector to be part of a wider sustainability movement in the built environment, where the retrofit of existing older buildings of all types, protected or otherwise, are seen as part of the solution, not the problem. By adopting a conservation approach in all buildings more carbon can be saved, and more buildings retrofitted appropriately.

This study proposes a digitalization framework for historic buildings. In this framework, advanced techniques, like Internet of Things (IoT), cloud computing, and artificial intelligence (AI), are utilized to create digital twins for historic buildings. A digital twin is a software representation of a physical object. This study uses digital twins to protect, predict, and optimize through analytics of real-time and historical data of selected features. Heterogeneous data of historic buildings, such as indoor environment, energy consumption metering, and outdoor climate, are collected with proper sensors or retrieved from other data sources. Then, these data are periodically uploaded and stored in the database of the cloud platform. Based on these data, AI models are trained through appropriate machine learning algorithms to monitor historic buildings, predict energy consumption, and control energy-consuming equipment autonomously to reach the balance of energy efficiency, building conservation, and human comfort. The cloud-based characteristic of our digitalization framework makes the digital twins developed in this study easy to be transplanted to many other historic buildings in Sweden and other countries.

The overall energy goals mean that more and more extensive measures need to be applied on buildings with varying degrees of heritage value. Previous studies show that there are a number of measures that have a beneficial impact on different parts of the energy system in historic buildings. What is now needed is a holistic approach that provides an opportunity to prioritize which measures are most important and should be combined. An ongoing research project is working on a method that will enable the reduction of energy and power needs for historic buildings on a larger scale by allowing different actors to choose optimal combinations of measures out of a number of important parameters. This paper identifies such parameters, as well as five cases for a future case study on combined measures. The effect of the implementation of various measures regarding both energy and power will be reviewed and interviews will be conducted with owners and managers of buildings to gather their quantitative and qualitative experiences regarding such measures. Finally, the most relevant energy measures are listed for further analysis in future simulation studies.

Implementing energy efficiency measures in historic buildings is a challenging task and require knowledge in a number of different disciplines. The measures to reduce energy use must create a good indoor environment without jeopardizing the loss of important cultural historical values or entailing damages to building materials or load-bearing structures. Building antiquarian-, building biological- and building physical aspects are central, and must be taken into account in the entire process, from planning to implementation of energy update measures in historic buildings. This paper presents a methodology for status determination and risk assessment of energy measures in historic buildings. The method (KuReRA) has been developed in collaboration between curators, building biologists and building physicists.

The aim of the paper is to outline the state-of-the-art in the field of historic buildings' energy retrofit through high-performance materials or innovative solutions. The research question is to understand if the latter can be positively applied to historic building in terms of compatibility and can contribute to create tailor-made solutions, avoiding or mitigating critical issues from the preservation point of view. This required the evaluation of many publications including papers, handbooks, booklets, and guidance as well as research reports. The literature review was then summarized in two research fields for each building element: retrofit solutions and high-performance materials and solutions applied to historic buildings. The technical properties of these highly efficient materials and their possible uses in heritage buildings are shown through the comparison and the data analysis of some case studies. Starting from a general reasoning on retrofit solutions and the interactions between the various building components within a whole building energy retrofit project, the paper assesses how high-performance materials are or are not widespread, which kind of data is available and what is still missing.

The objective of this work is to quantify the effects of the short-term climate change with a multiyear (MY) approach on the results of the heat and moisture transfer simulations of an historic building located in Udine (Italy) and to evaluate if a single year simulation could be representative of the results obtained with the MY. The hygrothermal performance and the moisture related risk are evaluated for a brick wall with and without insulation, with a MY of 25 years and with three single years selected form the MY. The software DELPHIN is used for the simulations and the damage indicators are calculated using simplified methods (number of days with unfavourable conditions). Depending on the damage considered, the years have different effects on the studied wall. The simulations that use the MY weather file allow to obtain more accurate results than using one-year simulations, but the effort and time required for the interpretation of the simulation results could be not acceptable. It is then shown that the choice of a representative weather file is crucial to the results of the risk analysis and that considering more than one weather file is necessary to obtain representative results for different damages mechanisms.

In the past decades several researches have been related to energy saving and emissions reduction. The technologies that exploit passive natural ventilation, like ventilated roofs and façades, have been recognized as the effective methods to provide energy saving and comfort. Ventilated façades represent dry assembled coating systems for buildings, traditionally made of panels in different materials. Very few ventilated façade systems with plaster finishes are already present on the building market. The potentiality of their design solution can be considered, e.g., when an historic building has to be recovered, since they can enhance the energy efficiency of building without changing its appearance. CFD simulations have been carried out by the authors in order to analyze the thermal energy behavior of a ventilated façade system with a plaster finishing and for comparing the benefits derived from its use to the corresponding unvented insulated façade. The ventilated façade shows a relevant energy saving thanks to the effect of ventilation: a reduction of 70% of heat flux was achieved, furthermore, a reverse conductance calculation showed relevant differences with the same calculated by thermo-physical material properties, since in this last calculation the heat and mass transport effect are not considered.

For the Otto Wagner area which is situated in the west of Vienna, one pavilion is selected to be refurbished for sustainable and energy-efficient construction to simulate the thermal and energy performance of the building. The selected pavilion has been redesigned to be used as a student residence while preserving the cultural heritage. A dynamic building simulation model is used to improve the energy efficiency and livelihood of Otto Wagner area with the main focus on heritage conservation. The pavilion of four levels is re-designed according to the proposed regulations of plus energy university building to become a student residence. The energy demand can be decreased while preserving the buildings' heritage requirements. Various changes are made through Sefaira tool in SketchUp model: optimization of the U-values of roof, walls and floor, addition of different layers of sustainable energy efficient insulation materials to decrease the overall energy demand, vacuum insulated panels and rigid cellulose board used to maintain existing roofline and calcium silicate boards to allow for vapor permeability in the brick walls, all working towards achieving the standards of zero energy buildings in Austria. The specific energy demands for heating, cooling and lighting are decreased in the proposed model to reduce the overall energy demand. The main goal of this study is achieving a plus energy district for the entire Otto Wagner area by improving the building envelope and integrating renewable energies using Polysun simulation tool. The selected building achieved the standards of zero energy buildings in Austria by optimizing the energy performance and to assess the thermal comfort in the building, both natural ventilation and mechanical ventilation are used to reduce the summer loads.

Materials' drying behaviour plays an important role in the renovation of historic buildings since internal insulation is frequently used to avoid intervening on the outer finish. However, the use of internal insulation in many cases requires the verification of the insulated wall system by means of hygrothermal dynamic simulations. As simulation models are a mathematical simplification of the physical reality, there is no guarantee that the model describes the hygrothermal performance accurately. A qualitative comparison of simulations with a drying coefficient that is based purely on experimental data provides additional security and clarity in the adoption of capillary active insulation materials. New approaches for the laboratory tests developed in parallel in two different research projects, Interreg AS ATLAS and HyLAB, are presented in this paper. An analysis of the drying apparatus designed by Scheffler revealed a series of limitations that could be further improved. The results of the material calcium silicate of two different experimental set ups, with considerations to the usability and accuracy of the apparatus, are presented, compared and discussed in the following paper. Further simulations resulted in comparable drying coefficients for the two experimental set-ups and were able to identify possible discrepancies in the results of the measurements.

In recent years the Building Energy Modelling (BEM) has emerged. It is based on BIM technology, that uses pre-designed BIM models to create an input for BEM tools, providing an opportunity to make BEM a time-saving, practical and accurate process. This format works quite efficiently for geometric information, while it presents interoperability issues due technical data loss. This study aims at creating a tool that collects and imports information in the BIM model in order to be exported by the IFC standard and read by the energy analysis software, crossing from BIM to BEM model. Considering the complexity of historic buildings' energy retrofit design, it is crucial to find and develop a fluid method that can automatically transfer the needed information, reducing considerably the time spent on preparing the BEM model. To achieve this goal, an open source Visual Programming Language tool and a specific Property Set for IFC exportation have been used. It was possible to transfer the needed parameters, while restricting as much as possible the human's transcription mistakes. This approach has been applied to the energy preliminary analyses of an historic farmstead near Milan, proving the decrease in time spent on transcribing, exporting and checking parameters. Due to the possibility of saving and reproducing VPL scripts in different BIM projects, the results of this study will be easily replicable and could be a usable tool for designers.

A dramatic improvement of the efficiency of existing dwellings is essential to tackle the climate emergency. About 30% of the European domestic building stock is classified as heritage, with generally poor thermal performance. While retrofitting of historic buildings is therefore essential, it presents increased challenges and risks compared to more modern ones. This is due to preservation requirements, the wider range of pre-retrofit conditions, the limited availability of reliable information on the building fabric and its complex hygrothermal behaviour. These challenges are reflected in the limited ability of current simulation tools to provide representative energy performance estimations for historic buildings, where large discrepancies with in-situ measurements are often unacceptable. This research compared three common dynamic simulation tools (EnergyPlus, IESVE, and WUFI Plus) to explore their relative strengths and weaknesses within the context of historic buildings. A 18th century barn was used as case study. Energy demand, indoor temperature and relative humidity outputs were assessed and compared using descriptive and inferential statistics. Results showed the importance of tool selection depending on the aim of the analysis. While IESVE and EnergyPlus showed similar results for energy performance and heating loads; WUFI Plus and IESVE were more consistent for indoor conditions and thermal comfort evaluation.

This paper deals with the consideration of driving rain penetration in exposed half-timbered walls within hygrothermal simulations. On the basis of a real damage pattern, a model is created which forms the basis for a parameter study. The aim of this study is to find out how the penetration of driving rain can be represented in such a way that the damage can be explained by it. For this purpose, (i) a moisture source that depends on the wind-driven rain is increased in intensity according to the standard, (ii) pulses of increasing intensity as well as (iii) constant moisture sources again increased by a factor are implemented. The results show that with the assumptions made, a local moisture source has little effect on the overall water content of the structure. However, depending on the moisture source intensity, a local damage risk for the wood near the joint could be observed. The damage of the case study can be derived, at least in part, from these results. The approach of assuming 1% of the driving rain as the moisture source does not seem to be sufficiently dimensioned. Quantifying the moisture sources for an exposed truss wall is a task for further investigation.

Void Insulation Panels (VIP) or Vacuum Insulation Panels are a technology that allows a sufficient thermal resistance for walls, floor or roof with a small thickness. The solution is more expensive than traditional ones but in historic centres of large cities with high value apartments, it could be an innovative solution for improving thermal comfort and reducing energy consumption. Different configurations of insulation with VIP in historical buildings in Bordeaux and Paris, two of the most expensive cities in France, are studied. The results show a great interest but moisture risk, especially in Bordeaux where the climate is wet due to the Atlantic coast. Special care for the thermal bridges and for the plaster hourdis between the beams of the floor are needed and the vapour barrier has to be continuous on top of the VIP complex plus insulation filler.

Hygrothermal simulations are expected to provide powerful support to the design process in the context of energy retrofit of historic buildings and prevent the moisture-related damages. They can be used to predict the hygrothermal behaviour of the building in detail and exclude the occurrence of moisture related damages, such as mould formation or material degradation. However, these simulations require various input data related to materials and boundary conditions, which are often difficult to find during the design phase. In this article we analyse the potential of hygrothermal simulations in predicting the hygrothermal behaviour of an internally insulated wall, even with limited information on the hygrothermal properties of the materials composing the historical wall. The quality of the simulation's results is evaluated through a comparison with monitored data. The numerical model is calibrated to maximise the agreement with the monitored data. The considered case study is a historical building located nearby Bolzano (Northern Italy). The monitoring system is installed with the aim of analysing temperature and relative humidity profiles within the construction. In addition, the climatic boundary conditions are measured both inside and outside the building, including temperature, relative humidity, driving rain and solar radiation. The numerical simulation of the wall under analysis is performed with the software DELPHIN.

Within the framework of a project funded by the Federal Ministry of Economics and Energy (BMWi) in Germany, it is being examined how, with different approaches, even historic buildings can contribute to an energy-efficient heritage district. Five partners are investigating the legal, structural and technical conditions for improving the building envelope in line with the preservation order, modernizing the buildings and providing a future-oriented energy supply. The inclusion of renewable energies and the digital networking of all components is of particular importance. For this all suitable measures will be adapted in five buildings for demonstration. Then, on basis of an extensive monitoring, the theoretically elaborated model approaches and the results obtained by means of numerical simulations can be validated. The joint project started in 2016. The IWB of University of Stuttgart as coordinator, the Margarethe Krupp Foundation as owner, the Gas and Heat Institute Essen e.V. and two institutes of the RWTH Aachen University, the Institute for Integrated Analog Circuits and the Institute for Building and Climate Technology, are partners in the research network.

Interior insulation is a crucial retrofit measure to improve the energy performance of historical building while preserving their exterior appearance. However, it affects the hygrothermal behaviour of the wall and for this reason it must be planned with a very detailed and careful approach. This becomes even more important when dealing with buildings that are subject to extreme climate conditions such as mountain huts. They are typically exposed to very cold temperatures for all year and to an elevated driving rain load. This paper presents the methodology followed to design the interior insulation intervention of a mountain hut located in Trentino-Alto Adige (Italy). The methodology is centred around the use of hygrothermal dynamical simulations at component level, but several other tools are used to identify the right input for these simulations: the analysis of monitoring data of nearby weather stations to define the exterior climate, simulations at the building level to calculate the interior climate and laboratory measurements to identify the correct material properties.

Children spend a large part of their growing years in schools, so it is essential to monitor and maximize the indoor air quality (IAQ) of the classrooms. In South Tyrol (northern Italy) many schools are characterised as historic and heritage buildings and improving IAQ poses a great challenge because of the need to maintain the integrity of the architectural characteristics of the structure. The aim of this paper is to provide insights into the effectiveness of a commercial low-cost smart CO₂-based visual alerting system used to improve IAQ in an urban kindergarten located in a historic building. Air temperature, relative humidity, along with indoor and outdoor air pollutants, were monitored in a classroom of 22 occupants before and after installation of the passive system. Based on high indoor CO₂ concentration and other parameters, the device alerts when to open the windows to facilitate air exchange. This research focuses on the measurements during the first few weeks after installation of the smart device. It did not show a considerable decrease in the CO₂ levels, but an improvement is desirable as the occupants become more familiar with the device. This will allow heritage buildings to guarantee a healthier environment in a simple and low-cost way.