Retrofitting Of Buildings Research Articles

Inclusiveness of Public Space: Experimental Approaches for the Revitalisation of Smaller Historic Urban Centres

In recent decades, many small Italian historic centers—particularly those situated inland—have witnessed a population decline due to inadequate access to public services and facilities. However, this depopulation has also allowed many centers to retain their distinctive features, now conferring upon them great cultural–historical and landscape value. New quality-of-life-centered economic models present the development of accessible public services as a necessity. Such a process could catalyze the recovery and growth of these centers, which continue to be deserted, regardless of their value. This paper considers combined solutions, including sustainable mobility, digital accessibility, networked services, and technological devices by applying them to trans-scalar studies with the goal of achieving sustainable outcomes. Some of the proposed solutions are the resolution of irregular ground levels, the use of electric vehicles, the creation of sharing models, the physical overhaul of routes, and the retrofitting of minor buildings for inclusive use in a comprehensive human-centered approach toward regeneration. This study is in line with the European guidelines for sustainable and intelligent mobility, whose goal is for at least one hundred European cities to become accessible to all and shifted to zero-emission mobility. Here, sustainable and smart mobility is understood not only as an improvement of environmental and social conditions, but also as a catalyst for environmental and social improvements and as an opportunity to enhance the livability of smaller, geographically isolated historic centers, moving toward a new economy of urban reclamation.

Nonlinear 3D Finite Element Analysis of a Coupled Soil–Structure System by a Deterministic Approach

Fully coupled soil–structure analyses were performed for a building of strategic importance located in the city of Messina (Sicily, Italy). The structure was built after the destructive 1908 earthquake, also known as the ‘Messina and Reggio Calabria earthquake’, which caused severe ground shaking. A parametric study considering three seismograms of this earthquake was performed. Deep in situ and laboratory investigations allowed the definition of the geometric and geotechnical model of the subsoil. Numerical analyses were performed with PLAXIS3D finite element software (Version 21.01.00.479). The Hardening Soil model with small-strain stiffness was accurately calibrated using laboratory and field data. The dynamic response was investigated in terms of accelerations, response spectra, amplification functions, displacements and stress–strain hysteretic loops. The findings show that many aspects must be investigated for the retrofitting of buildings with shallow foundation in areas characterized by a medium to high level of seismic risk: (i) a key role is played by an accurate investigation of the soil; taking into account the specific conditions of the soil, it was possible to investigate its filtering effects; (ii) the dynamic response of the fully-coupled soil–structure system deviates from the free field-site response analysis; (iii) the results reveal the importance of considering the soil nonlinearity in seismic soil–structure interaction problems.

Investigating Energy Renovation of Multi-Owner Buildings and Real Estate Market Issues in a Degraded Greek Urban Area

States establish ambitious policies and important measures to achieve targets for the energy upgrade of buildings but although some important barriers prevent their implementation in space, they are rather overlooked by research. In this paper, it is argued that extensive multi-ownership (MO) and weak performance of the real estate market in degraded urban areas impede the mass energy retrofitting of multi-owner buildings (MOBs), which are an important part of the urban building stock A deprived area of central Athens (Greece) that serves as a case study. With a pluridisciplinary approach based on extensive field surveys, cadastral data analysis and cases of energy renovation of buildings through a public–private partnership financing scheme as well as ways to overcome the MO issue were explored, according to the provisions of the Greek legal framework. The integrated urban regeneration approach is promoted as a means to encounter the MO issue and enhance the functioning of the real estate market by the generation of surplus values that will render the energy retrofitting of buildings more attractive to investors and thus achieve the deep renovation of MOBs towards the sustainability of the urban environment. This paper ultimately advocates the integration of energy planning with spatial planning.

A distributed collaborative platform for multi-stakeholder multi-level management of renovation projects

To meet European energy-saving and decarbonisation goals, the annual renovation rate of buildings requires to be at least twice its current level; an aspiration to which the use of innovative and automated solutions can contribute. This paper presents such a solution, the RINNO Retrofitting Manager (RRM) which is part of a large, ambitious research and development project (RINNO) that aims to provide an augmented intelligence-enabled framework for deep, energy-focused retrofitting of buildings. The RRM uses web-service technologies to rationalise the retrofitting process and optimise the delivery of renovation works, while making data readily accessible through an integrated set of role-based user interfaces. The RRM is designed and developed as an open distributed system, that is extensible and portable, by implementing a collaborative research and development approach. The RRM platform implements a multi-level, multi-stakeholder planning approach. It addresses the dearth, insufficiency, and isolation of existing renovation tools by enhancing collaboration, interoperability, and data security, and avoiding information loss and misunderstanding. Employing the Unified Theory of Acceptance and Use of Technology (UTAUT) model, tests conducted with users from independent construction organisations confirmed the RRM's satisfactory performance, ease of deployment, and overall suitability for the management of renovation projects. While this research provides a free collaborative platform for managing renovation projects that can be used by all building retrofit stakeholders in Europe, it also introduces a set of web-services that can be easily reused by third-party developers and integrated into their software tools.

Cost performance analysis of green chemical industrial buildings using blockchain-BIM

ABSTRACT Blockchain technologies have recently garnered substantial attention in research and industry sectors due to their potential advantages across various industries. Blockchain provides an effective solution to address challenges by offering distributed, secure, and permissioned transactional ledgers. This paper introduces an innovative conceptual framework that integrates blockchain technology with building information modeling, specifically designed for digital transactions and smart contracts in the retrofitting of green buildings within the chemical industry. The core objectives include enhancing cost efficiency, fortifying cybersecurity measures, improving information management and sharing, simplifying payment transactions, and promoting sustainability in this specific context. The research, conducted at a chemical facility in Cilegon, Banten, Indonesia, utilizes Structural Equation Modeling-Partial Least Squares (SEM-PLS) to analyze questionnaire data and identify influential factors. Results indicate that incorporating Blockchain-BIM leads to cost savings of 4.42%, 4.45%, and 4.40% for low-level, medium-level, and high-level retrofitting categories, respectively, highlighting the significant role of Blockchain-BIM in enhancing cost efficiency throughout the retrofitting process.

Displacement-based design procedure for the seismic retrofit of existing buildings with self-centering dissipative braces

Existing framed buildings, especially those designed according to outdated seismic codes, often offer inadequate seismic protection levels due to material degradation, low amount of reinforcement and poor construction details. Among the possible retrofit strategies, elasto-plastic dissipative braces (EPDBs) can be installed to provide supplemental stiffness and energy dissipation in the main resisting frame. Since they are based on the plastic deformation of sacrificial steel components, EPDBs are inherently affected by scarce recentering capability, i.e., presence of residual deformation at the end of the mainshock that could impair their effectiveness for aftershock events. As demonstrated in recent seismic sequences, there might be not enough time to restore (e.g., though hydraulic actuators and a reaction frame) the undeformed configuration of the structure before a subsequent shock. This issue can be overcome through self-centering dissipative braces (SCDBs), i.e., braces equipped with dampers characterized by a “flag-shaped” hysteretic behavior, which inherently facilitates the immediate re-centering of the frame. Despite this evident benefit, there is still lack of practical design procedures for the seismic retrofit of buildings through SCDBs. To fill this gap, a direct displacement-based design procedure for SCDBs tailored to building frames is here conceived and illustrated. The proposed method aims at achieving simultaneously two performance requirements: (i) a target maximum roof displacement under the ultimate-limit-state seismic event; (ii) the absence of significant residual inter-storey drifts at the end of the shaking. The implementation of the procedure is described by two applications to a steel and to a reinforced concrete case-study building. Nonlinear time-history analyses are carried out to prove the effectiveness of the proposed method, along with a comparison of the seismic performance offered by SCDBs versus traditional EPDBs implemented in the same case-study buildings.

Energy performance analysis of alternative building retrofit interventions for the four climatic zones of Greece

Climatic conditions determine which retrofit strategy can result in a satisfactory improvement of a building's thermal performance. This study systematically investigates alternative retrofit actions, as standalone and in combination, and assesses their energy performance. The retrofit actions include i) insulation on the external walls, ii) the incorporation of phase change material (PCM) on the roof and the increase of the building thermal inertia, iii) a mechanical ventilation system with a summer period operation, and iv) a cool roof coating. The energy analysis concerns a typical two-story family building and the four climatic categories of Greece and is conducted with the INTEMA.building tool, a dynamic energy analysis software developed in Modelica language. The importance of the present study is that it serves as a guideline for the selection of the energetically optimum single retrofit or multiple-retrofit strategy regarding a building's location climatic data, and provides calculations concerning the annual heating and cooling loads, and the corresponding heat pump electricity consumption. The retrofit actions of external wall insulation and PCM roof addition are characterized as more effective in reducing a building's heating energy loads, while the mechanical ventilation system and cool roof coating are more effective in reducing a building's cooling loads. The quadruple retrofit strategy results in the maximum electricity savings for Heraklion (28.01%), Athens (21.15%), and Thessaloniki (16.54%), while the triple retrofit strategy which does not include the cool roof coating, results in the maximum electricity savings for Kastoria (10.79%). Lastly, an economic analysis of the energetically optimum renovation strategies is conducted.

Assessing the Energy Performance and Retrofit Potential of the 1980–1990s’ Residential Building Stock in China’s Jiangsu Province: A Simulation-Based Study

The building operation sector in China represents 22% of the national energy consumption and 22% of the carbon emission, of which urban residential buildings accounted for 24% in 2019. Such figures for the housing sector are projected to increase sharply in the near future, while China aims to peak CO2 emissions by 2030 and reach neutrality before 2060. To reduce the impacts of the urban housing sector and address the energy use and waste generated by large-scale demolition and reconstruction, the central government started promoting the energy retrofit of urban residential buildings, raising such policies to the national strategic level. Jiangsu Province is one of the most urbanised, with a rapid growth in the energy consumption of residential buildings. The Multi-Danyuan and Single-Danyuan Apartment built in 1980–1999 are the most representative residential types in its urban areas. While still adequate functionally, they were designed and built to low energy standards and show significant potential for energy retrofit. Nonetheless, their current performance and energy-saving potential are under-researched, while more detailed and reliable data would be critical to support retrofit design and policy making. This study investigates and characterises the typical use and energy performance of the two building types. Additionally, seven measures and six retrofit scenarios were identified based on the optimal energy reductions and regulations from selected countries. The simulations indicate that, without intervention, the energy consumption of the typical urban residential buildings can reach 122 kWh/m2 under the typical high-energy user scenario. By selecting a set of effective energy-saving measures, the operational energy use for heating and cooling can be reduced by up to 52.4%. Current local standards prove cost-efficient, although less effective in reducing energy use compared to international best practices, indicating potential improvements to the contribution of building retrofit towards achieving the national carbon reduction goals.

Transfer of building retrofitting evaluations for data-scarce conditions: An empirical study for Sweden to China

Evaluating and comparing the performances of different strategies is critical for energy-efficient building retrofitting. Data-driven modelling based on large building performance datasets is an effective method for such evaluations. However, it could be challenging to apply this approach to buildings from data-scarce areas where local building performance datasets have not been well-established, which means the data falls short of the high demand for building retrofitting on a global level. To address this, a transfer learning approach is proposed in this study that can evaluate the performance of buildings without local well-established building performance datasets. The proposed approach is applied in the Swedish-Chinese empirical study that relies on the Swedish dataset to transfer and predict the building performance in China without well-established datasets. It was achieved by applying fuzzy C-means clustering and a neural network (FCM-BRBNN) to pre-train the evaluation model based on the Swedish dataset. Then, the proposed approach collects a small sample of Chinese buildings in the data-scarce area and transfers the model to local building performance prediction. The results show that the transfer learning approach can reliably predict the performance of building retrofitting in data-scarce areas with only hundreds of local building samples. As such, this study provides a novel methodology that can support the evaluation and comparison of retrofitting strategies in data-scarce regions and countries with only limited local data. It could efficiently assist designers in optimizing energy-efficient designs in the pre-retrofit stage. Crucially, the methodology enables the transfer of knowledge regarding building performance across different countries and regions, being pivotal for the international collaboration required to stimulate the global energy-efficiency transformation.

Seismic design and performance assessment of a retrofitted building with tuned viscous mass dampers (TVMD)

Vibration control technologies have been widely implemented for the seismic retrofitting of buildings in high seismic regions. Among various vibration control devices, the tuned viscous mass damper (TVMD) has proven effective in mitigating both lateral inter-story drifts and floor accelerations. This paper presents the seismic design and performance assessment of a retrofitted structure located in a highly seismic area. The existing masonry building is being retrofitted into a steel frame-jacketed masonry wall interacting structural system installed with TVMDs. A simplified iterative design process is proposed for the tuning design of TVMDs used in the retrofitted structure, which is based on the fixed-point method. The seismic responses of the buildings are calculated using non-linear dynamic analysis in OpenSees. Applying the FEMA P-58 approach, the seismic performance of the buildings as measured by the repair cost and repair time is evaluated. The findings reveal that the majority of the structural damage is focused within the masonry walls, coupling beams, and non-structural components. Use of TVMDs results in reduced maximum inter-story drifts that when subjected to very rare earthquake (VRE) shaking are up to approximately 40% lower in both transverse and longitudinal directions compared with the uncontrolled structure. Owing to the effective control of seismic damage to both structural and non-structural components, the TVMD-equipped structure achieves a 42% reduction in median repair cost and a 46% reduction in median repair time at VRE compared with the uncontrolled building. The seismic performance assessment results also illustrate the advantages of TVMD control compared with conventional viscous dampers.

An effective decision-making method for building retrofit measures strategy

The energy efficiency and sustainability of existing buildings have become a critical concern in Algeria’s efforts to reduce energy consumption and mitigate environmental and economic impacts. To address this challenge, a systematic and effective decision-making method is required to select optimal building retrofit measures in alignment with Algeria’s 2030 energy strategy. In this study, we propose an innovative approach based on the Fuzzy Analytical Hierarchy Process (FAHP), a widely used multi-criteria decision-making method, to evaluate and prioritize different retrofit measures. The FAHP allows decision-makers to have a comprehensive framework for making informed choices by incorporating independently proposed economic, environmental and technical criteria. The results demonstrate the high significance of retrofit measures that enhance thermal insulation, with double glazing and roof insulation emerging as top priorities. Sensitivity analyses confirm the stability and robustness of the decision-making process. This approach offers valuable insights for policymakers and building professionals seeking to implement sustainable and energy-efficient retrofitting strategies in Algeria’s construction sector. By aligning with the country’s energy goals, this decision-making method contributes to achieving a more sustainable and environmentally responsible built environment.

Evaluating the Implementation of Energy Retrofits in Historic Buildings: A Demonstration of the Energy Conservation Potential and Lessons Learned for Upscaling

This study presents an in-depth analysis of 69 case studies focusing on the energy retrofit of historic buildings, uncovering challenges, best practices, and lessons learned to balance energy efficiency improvements with heritage preservation. The findings highlight several challenges encountered during renovations, such as complex heritage evaluations, restrictions on alterations, coordination issues with authorities, technical limitations, higher investment costs, and knowledge gaps. On the other hand, identifying factors promoting renovation, including demonstrating energy savings while respecting heritage, early collaboration between planners and authorities, and quantifying investments, could incentivize owners and authorities. The limitations of a still-limited sample size, occasional incomplete data, and potential sample bias call for cautious interpretation of the presented analysis. Despite these, the study provides valuable insights into successful projects, emphasizing the need for scalability, knowledge transfer from innovative policies, and targeted policy-making for successful replication. The study concludes with a call for further development of the HiBERatlas (Historic Building Energy Retrofit atlas), an extensive resource for historic building renovation, expanding its database, collaborating with agencies, and tailoring guidance for stakeholders to foster energy retrofits in heritage buildings.

Social acceptance of district heating: evidence from the Netherlands

AbstractThe Netherlands Climate Change Agreement aims to reduce CO2 emissions and seismic events by halting natural gas usage by 2050. This will require widespread societal acceptance by 90% of households. The study investigates the social acceptance of a district heating network (DHN) among social housing tenants in Haarlem, Netherlands. The findings of a survey administered to ninety-five tenants revealed a substantial level of support for the DHN project. A significant portion of respondents, 75%, expressed their approval for the DHN, surpassing the legally required threshold of 70% for implementing building retrofits. Findings imply that although the participants possess an adequate comprehension of the rationale for energy transition, their familiarity with the precise particulars and practical information pertaining to the proposed transition to DHN is inadequate. The level of trust in housing corporations, energy providers, and the municipality is uniformly low, indicating a lack of institutional trust. Generally, the interpersonal trust among tenants tends to be lower than their trust in the broader public, which in turn restricts their capacity for self-organization and exercising influence over energy institutions. Although DHNs are typically regarded as environmentally friendly and secure, there are several challenges that need to be addressed, including the uncertainty about who will cover the costs of transitioning and the doubts surrounding DHN feasibility (warmth and reliability). We suggest implementing interventions to improve tenants' comprehension of the DHN project's particulars (capability), provide practical information regarding costs and feasibility (motivation), and foster trust at both interpersonal and institutional levels (opportunity).

Optimizing sustainable building retrofits with Emperor Penguin Optimization: a machine-learning approach for energy consumption prediction

Optimizing sustainable building retrofits with Emperor Penguin Optimization: a machine-learning approach for energy consumption prediction

A modular framework for a dynamic residential building stock model with energy retrofit forecasts

Building retrofits are strongly dependent on the individual refurbishment/rehabilitation cycles of buildings. In order to achieve the targeted climate goals for the building sector, it is necessary to make the best possible use of refurbishment opportunities for energy retrofits. Furthermore, it must be considered that the younger the building, the lower the potential for energy savings. The most challenging, yet required, energy retrofits are all yet to come. Given the importance of the refurbishment cycle, the question arises as to what the theoretical refurbishment rate is, what the actual energy retrofit rate is, and what it needs to be in order to meet the climate targets for the residential building stock. The aim of this paper is to model the evolution of the size and retrofit status of national building stocks. This is to be done against the background of the deviation from the actual and theoretical refurbishment cycle. Using current statistics and the past development of the German residential building stock, central parameters like living space, new construction, deconstruction, and the retrofit rate are modeled endogenously. For the latter, influences of economic conditions are implemented through an exogenously set black box variable. The retrofit rate represents a deep energy retrofit and thus allows an easy connection of the model with energy parameters for building classes defined in the web database TABULA for 20 European countries. The results are of relevance for modeling the energy efficiency status of the building stock and deriving suitable conditions for increasing retrofit rates also in other countries. The results show that increasing the energy retrofit rates to 2%/a or more is largely unrealistic. Instead, the focus should be on weak points, especially where short-term savings are concerned. This applies in particular to facades, basement ceilings, and heating systems as well as the efficient use of energy in buildings.

Green Retrofitting of Building using BIM-based Sustainability Optimization

The construction industry consumes around 55 percent of Pakistan’s annual energy and is the country’s most energy-intensive sector. It is, therefore, significant to devise a novel and effective model of green retrofitting of current buildings based on Building Information Modelling (BIM) which aims to reduce building energy consumption to effectively meet diversified climatic concerns and to promote sustainable structures. This research aims to reform the existing building by modifying the design parameters for an inefficient building envelope based on BIM simulation and data optimization results to optimize the overall energy consumption. BIM tools, such as Autodesk Revit and DesignBuilder have been used for the evaluation of the optimized energy-efficient design by comparing different design alternatives. After a detailed analysis, this research has concluded that the existing building is consuming a high amount of annual energy. With the help of BIM tools, which possess advanced algorithms for an effective optimization process, a list of ‘green’ solutions i.e., optimal designs has been generated, out of which the optimal and cost-effective design saved 46% of energy in total. In this study, the design variables selection has been fulfilled according to the local environmental sustainability.

Influence of urban density on energy retrofit of building stock: case study of Spain

ABSTRACT Energy retrofitting of existing buildings plays a key role in the European targets of Green House Gas reduction. The addition or substitution of construction materials is needed to improve energy performance of buildings and its environmental impact must be considered. This paper proposes a model for the assessment of the environmental impact of neighborhood retrofit in relation with urban density. The model is based on the decomposition of buildings into functional elements and the quantification of construction materials used in building energy retrofitting. As a novelty, the need of road rehabilitation was also considered. The environmental impact was assessed in terms of Embodied Energy (EE) and Embodied Carbon (EC). The operational energy after retrofit was also calculated. The results bring the evidence of the relation between the urban density and the EE and EC derived from building retrofit, which can be up to 60% higher in low density areas. The sensitivity analysis carried out demonstrates the influence of the urban compactness on the environmental assessment results. The model proposed can assist in the design of retrofit plans at urban level by highlighting those retrofit measures with most significant environmental impact depending on the urban density.

Retrofit building energy performance evaluation using an energy signature-based symbolic hierarchical clustering method

Retrofitting existing buildings is crucial for significantly reducing energy consumption in the building sector. The continuous monitoring and evaluation of retrofit building energy efficiency is necessary to maintain optimal energy performance. This study proposes a novel method for evaluating building energy performance that combines energy signature analysis and hierarchical clustering. Symbolic data were defined by k-means using differences in gradients and y-intercepts before and after retrofitting extracted from energy signatures. Hierarchical clustering was then performed using the symbolic datasets. This symbolic hierarchical clustering method enhances the utility of open data and facilitates rapid decision-making. Additionally, it allows for a simple assessment of energy performance at the city scale. Through implementing this approach in 49 retrofitted buildings in Gangwon-do, South Korea, five types of symbolic data were identified (Types 0–4). Using hierarchical clustering, these buildings were clustered into six groups (Clusters 1–6). Type 3, representing ideal retrofitting outcomes, was observed in Clusters 2, 3, and 4 (73.47 % of all buildings). Conversely, Type 4 symbols, indicating a rebound effect, were observed in Cluster 1 and 2 (6.12 %). These findings provide meaningful information after retrofitting at the regional level, contributing to effective building management during retrofitting.

Carbon emission measurement of the envelope of a university teaching building in Hefei City

Abstract In response to the challenges posed by global warming, China has formulated dual carbon goals. In this context, the construction industry, a key carbon emitter, is vital for implementing energy-saving and emission-reducing strategies. This study zeroes in on the pivotal role of building envelope structures in carbon emissions, with a focus on a university building in Hefei. Commencing with onsite measurements to gather initial data, the study leverages simulation software to conduct an in-depth analysis. Employing orthogonal experimental design and variance analysis, it meticulously assesses the carbon emissions associated with different materials used in exterior walls, roofs and windows, considering both the material production and building operation phases. The research scrutinizes the impact of these materials on carbon emissions, with a special focus on the performance of seven distinct building retrofit schemes. Key findings of the study underscore that the type and thickness of exterior wall materials substantially influence carbon emissions during the production phase. Conversely, the choice of window materials emerges as more critical in reducing emissions during the building operation phase. The implementation of the various retrofit schemes demonstrates a tangible reduction in overall building carbon emissions. Specifically, these schemes yield a yearly reduction in carbon emissions of 2.96–3.62 tons during operation and a substantial decrease of 30.36–165.97 tons in the production phase, compared to the original structure of the case study building. These insights not only offer practical and viable strategies for the construction industry’s low-carbon development but also provide theoretical underpinnings and references for future building designs and retrofits.

Glowing and piloted flaming ignition of vertical wood exposed to power-law thermal radiation

Fire hazards are dangerous to human life and property safety. Fire accidents occur frequently in wood-frame villages all over the world. In this paper, glowing and flaming ignition of vertical wood heated by five power-law heat fluxes (HF) is experimentally studied using a self-built apparatus. Comparative ignition tests with and without piloted ignitor were performed, and some crucial variables were collected, encompassing surface and in-depth temperatures, mass loss rate, and ignition time. A 1D numerical model was developed to simulate experimental results and determine temperature-dependent thermodynamics of wood by inverse modelling. The results showed that ignitor induced flaming ignition, whereas absence of ignitor enabled only glowing ignition. Flaming ignition was preceded by flash ignition. Surface temperatures of flaming ignition were well predicted by numerical model. However, the predictive accuracy declined when modelling in-depth temperatures due to cracks in char layer. Three stages were identified in both ignition modes: a preheating stage, a water evaporation stage, and a pyrolysis stage. The numerical model underestimated mass loss rates due to additional heating contributed by flash ignition and char cracks. Critical temperature and critical mass flux were comparatively analyzed, and the former was used in assessing ignition time. Measured ignition times were well estimated by an analytical correlation. The numerical model accurately predicted flaming ignition times but overpredicted glowing ignition times due to char cracks. The proposed model can contribute to the fire safety retrofitting of historic buildings and minimize human casualties and property damage.