•A two-stage analysis method is proposed for analyzing the issue of local crack expansion in buildings under the influence of pit construction.•A three-dimensional fluid–solid coupling model of pit ...construction was established, along with a local structural crack expansion model based on XFEM.•The numerical model takes into account the initial cracks in the building and analyzes the impact of the size of these initial cracks.•Crack expansion control measures for damaged buildings are proposed.
In response to safety concerns arising from pit construction near existing damaged buildings, this paper introduces a two-stage analysis method. Initially, the finite element method is utilized to construct a comprehensive model of pit excavation, enabling the analysis of building settlement and internal forces induced by the construction activity. Subsequently, the resulting building settlement vectors are employed as displacement loads in a localized structural model established via the extended finite element method. This facilitates the examination of crack propagation within the damaged building under settlement influence. Application of the proposed method to a new pit construction scenario reveals a maximum differential settlement of the building at 5.35 mm. As building settlement increases, crack propagation within the building follows a slow-fast-slow trend, with an approximate crack propagation length of 9.6 m and an average depth of 0.13 m. Notably, deeper and longer initial cracks exacerbate wall crack propagation, leading to cracks penetrating the wall when initial crack depths exceed 100 mm. Furthermore, crack propagation extends to the slab, resulting in a 10.2 m long of crack when initial crack depth is 66 mm. A case study demonstrates the effectiveness of the proposed two-stage analysis method in addressing crack propagation issues in existing buildings during pit construction.
Older buildings often exhibit multiple problems, such as high energy consumption, high carbon emissions, and outdated performance. To achieve optimal decision-making for the energy efficiency ...retrofitting of existing buildings, a data fusion-based hybrid multicriteria decision-making method based on an extension-based trapezoidal cloud model (TCM), and a multidimensional renovation program evaluation index system including technical, safety, economic, and environmental applicability is proposed. The validity and applicability of the model is verified using an old building renovation as an example. The results indicate that (1) incorporating technical, safety, economic, and environmental suitability factors will enable future of building retrofitting to focus on sustainability. None of the current retrofit programs can economically cover the costs they incur through their energy saving benefits, which will not motivate owners to complete retrofitting and requires joint efforts between the government and the building industry to improve the sustainability of existing buildings. (2) Building retrofitting programs should primarily prioritize technical and economic applicability, which exhibit importance values of 0.2930 and 0.2496, respectively. (3) The stability of the retrofit effect is the primary reason for variations in the effectiveness of selected programs. A program with a greater degree of affiliation with levels I, II, and III of the index is more stable and less prone to deterioration than other programs. The proposed method provides an efficient decision-making tool for the selection of retrofit programs for existing buildings and is suitable for popularization and application, thus promoting building energy conservation, emission reduction and sustainable development.
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•An index system for existing building energy-saving retrofitting is constructed.•A multicriteria decision-making method based on an extension-based TCM is proposed.•The G1 and entropy weight method are combined to determine interaction relationships.•The proposed method is conducive to numerical transformation of qualitative indicators.
One of the largest threats to future development is climate change. Apparently, the building sector has been the largest source of greenhouse gas production. One prospective solution to this is ...“green building” that aims to provide environmentally sustainable building in terms of design, construction and maintenance. However, green buildings symbolize the next stage of buildings, and the recent growth of new green building constructions is inadequate to overcome the negative impact of existing buildings. One logical solution to reduce the environmental impact of the existing buildings is through green retrofitting. Yet there is lack of systematic review on the existing body of knowledge on green retrofitting which is critical for future research. This paper aims to critically review the existing literature on green retrofitting and to identify contemporary research trends. Additionally, with the view to the current challenges, barriers, obstacles or problems to green retrofitting, this study highlights the needs to identify the Critical Success Factors (CSFs) for successful implementation of green retrofit projects.
Green retrofit is an effective way of improving the performance of existing buildings to achieve low energy consumption and low carbon emission. To realize a successful building green retrofit, it is ...important to understand the barriers and to develop relevant policies for retrofitting existing buildings, especially in developing countries. As a typical developing country, China has a large number of aged buildings with high green retrofit potential. In terms of its government structure, economic development, and building stocks, China is unique in that it poses a unique set of barriers and policy strategies on the promotion of building green retrofit. Based on a critical review, existing retrofit policies in China were reviewed. Then, the barriers to building green retrofit within the context of China were identified. Based on the study of existing policies and barriers, relevant policies for addressing these barriers are recommended. The findings provide a valuable reference for policy makers in China to review current building green retrofit policies or to develop new policies that address the barriers. This study also provides a useful reference for other countries aiming to review their building green retrofit policies.
•The relationships between building retrofit policies were examined.•A series of building retrofit policies have been implemented in China.•The barriers to building green retrofit in China were identified.•Six recommendations were proposed for China to overcome the barriers.
The current European building stock is ageing and requires significant renovation efforts to improve its energy performance and ensure structsural safety. As part of the key actions of the European ...Green Deal, increased building renovations, a `renovation wave', is needed to ensure that the ambitious EU energy saving and decarbonisation goals can be reached by 2030 and 2050, accordingly. To incentivise renovation further, integrating energy retrofitting with seismic strengthening is explored in this study. A combined energy and seismic retrofitting is investigated across twenty European cities with varied seismic hazard levels and different climatic conditions. Typical building types are defined both in terms of their energy and structural characteristics and are associated to the building population of each city. A monetary metric for combined assessments based on expected annual losses from energy costs and seismic losses is used and an optimum retrofitting scenario is identified. By means of the proposed renovation rate of 3%, a reduction of approximately 30% of primary energy use and CO2 emissions may be achieved within a decade. Taking into account energy costs and costs related to structural damage it is found that a combined retrofitting scheme will reduce substantially the payback periods in moderate to high seismicity regions. In such locations the combined energy and seismic retrofitting is justified and proposed instead of the sole energy retrofitting typically applied today in existing buildings.
•A comprehensive review of optimizing energy performance of existing buildings is presented.•Studies are discussed according to their decision-making model, measures and variables, software tools, ...etc.•A table of reviewed studies is presented that provides an overview of previous works at a glance.•Gaps for future works in this research area are outlined.
Energy retrofit and renovation of existing buildings have an effective role in reducing carbon dioxide emissions and ultimately global warming. Therefore, there is an increasing interest in this field of research. The aim of this paper is to offer a complete, precise, up-to-date literature review on energy performance optimization of existing buildings.
The literature is analyzed and discussed towards decision-making model, measures and variables, objectives and criteria, software tools, optimization methods, case studies geographical locations and case studies building types. Finally, trends and future research opportunities are presented. The results of the review show that in spite of numerous conducted studies, some optimization objectives such as aspects of comfort conditions, except thermal comfort, and some types of weather conditions have been neglected. Additionally, there is a need for creating a novel decision-making tool reducing computational time of optimization and increasing reliability on the optimal packages. This article provides an extensive overview for researchers to define their outlines in this area.
This research investigated the first zero energy building (ZEB) in Southeast Asia which was retrofitted from an existing building and incorporated diverse passive and active design strategies for the ...tropical climate. The study disclosed the efficiency improvement through each individual design strategy and also compared the cost-effectiveness of active and passive categories. The most cost effective active strategy was efficient lighting; and the second was efficient air conditioning systems. The most cost effective passive strategy was lighting pies; and the second was lighting controls. Generally, passive strategies might have longer period of payback. It should be noted that the ZEB was a test-bedding project; therefore, the finding on passive design cost-effectiveness should be cautiously interpreted considering the scale of applications. The research suggests that active and passive strategies should be integrated into building design to optimize the energy performance. Particularly, passive design shall be applied in a large scale to have significant energy improvements.
Optimizing energy consumption in the cities might present a significant impact on decarbonization strategies approaching carbon neutral future in 2050. Positive Energy Block initiative is targeted ...particularly to densely build environments promoting shared on-site renewable energy production and storage, using smart grids, internet and communication technologies, Internet of Things and other highly advanced energy efficiency technologies within the neighborhoods. Research presented focuses on transition from traditional urban block to Positive Energy Block in valuable environment of historic city center exploring possibilities of waste heat regeneration and on-site renewable energy technologies. Energy consumption data is analyzed and the conception for possibilities of on – site renewable energy generation and waste heat recovery from data centers and cooling units in selected urban block is drawn. The results indicate that very ambitious targets for energy efficiency improvement are needed to achieve positive energy block – 65% and 60% for electricity and heating consumption, respectively. Possible savings of CO2 emissions are 45–50 kg/m2 per year.
•Overall methodology for transition from traditional historic urban block to Positive Energy Block is developed.•Waste heat recovery from data center located within the block is incorporated in decarbonisation strategy.•Preliminary calculation of decarbonisation potential of selected urban block is performed.•After deep renovation 100% of thermal energy and 70% of electricity needed for selected can be covered with on – site RES.•To cover heating and electricity demand, 65% cut of electricity and 60% cut in heating demand is needed in selected block.
The Chairul Saleh Building or the Secretariat General Office Building has implemented the Energy Management Program since 2016. In this study, an assessment was carried out based on the GBCI ...environmental assessment tool, especially for aspects of land use, energy efficiency and conservation, water conservation, and building environmental management aspects. The requirement analysis to get a green predicate is provided by points assessment which fullfillment the standard. Chairul Saleh building has implemented 10 of the 16 points in Appropriate Site Development category. Energy efficiency and conservation, Chairul Saleh building has implemented 29 of the 36 maximum points. Water Conservation category managed to get 5 out of 20 maximum points, while Building Environmental Management managed to get 11 out of 13 points, Material Resource and Cycle get 8 out of 12 points, Indoor Health and Comfort, get 9 out of 20 points, which was determined in the GBCI greenship rating tools for existing building. The result revealed that in the total value of Chairul Saleh Building was 72 points, it meants achived the Gold certification. Based on the rating set by the GBCI greenship, the Chairul Saleh building is currently awarded a Gold rating for its ability to apply the green building standard.
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