Multi-subject and multi-objective integrated optimization system and implementation strategy for energy-saving renovation of the existing residential buildings

The core of the healthy and orderly operation of the existing residential building energy-saving renovation market lies in the exploration of the implementation mechanism of multi-subject and multi-objective integrated optimization.The multi-agent and multi-objective integrated optimization system framework is a powerful tool to guide the scientific decision-making of the market core structural entities in the future market practice. This paper analyzes the practical dilemma of energy-saving renovation of theexisting residential buildings in China, summarizes the practical experience of multi-subject and multi-objective integrated optimization of energy-saving renovation of the existing residential buildings in foreign countries, and puts forward beneficial practical enlightenment on the basis of comparison at home and abroad;The design principles of the target integrated optimization system have established a multi-subject and multi-objective integrated optimization system framework for the energy-saving renovation of the existing residential buildings, from six aspects: government guidance, trust consensus, value co-creation, risk sharing, revenue sharing, and social responsibility sharing. This paper proposes a multi-subject and multi-objective integrated practice strategy, in order to promote the efficient and orderly development of China's existing residential building energy-saving renovation market.

Research on the Spatial Characteristics of Traditional Residential Buildings in Ningxia Region

This article takes traditional residential buildings in Ningxia region as the starting point,and through field research and data analysis,demonstrates the specific elements of the spatial composition of traditional residential buildings and the common forms of courtyard space.The study summarizes the regional cultural characteristics of traditional residential buildings in the region,laying a foundation for subsequent research and providing some reference basis.

Demand Flexibility of Residential Buildings:Definitions,Flexible Loads,and Quantification Methods

This paper reviews recent research on the demand flexibility of residential buildings in regard to definitions,flexible loads,and quantification methods.A systematic distinction of the terminology is made,including the demand flexibility,operation flexibility,and energy flexibility of buildings.A comprehensive definition of building demand flexibility is proposed based on an analysis of the existing definitions.Moreover,the flexibility capabilities and operation characteristics of the main residential flexible loads are summarized and compared.Models and evaluation indicators to quantify the flexibility of these flexible loads are reviewed and summarized.Current research gaps and challenges are identified and analyzed as well.The results indicate that previous studies have focused on the flexibility of central air conditioning,electric water heaters,wet appliances,refrigerators,and lighting,where the proportion of studies focusing on each of these subjects is 36.7%,25.7%,14.7%,9.2%,and 8.3%,respectively.These flexible loads are different in running modes,usage frequencies,seasons,and capabilities for shedding,shifting,and modulation,while their response characteristics are not yet clear.Furthermore,recommendations are given for the application of white-,black-,and grey-box models for modeling flexible loads in different situations.Numerous static flexibility evaluation indicators that are based on the aspects of power,temporality,energy,efficiency,economics,and the environment have been proposed in previous publications,but a consensus and standardized evaluation framework is lacking.This review can help readers better understand building demand flexibility and learn about the characteristics of different residential flexible loads,while also providing suggestions for future research on the modeling techniques and evaluation metrics of residential building demand flexibility.

Study on Dominant Expression of Regional Culture of the Qinling Mountains in Local Residential Buildings

Regional culture of the Qinling Mountains shows distinct features since it was born in the local outstanding ecological environment, study on local architecture is significant for the dominant expression of regional culture, protection of local environment, and echoing with the theme of ecological civilization construction. This paper, on the basis of the mutual infl uence and evolution of regional culture and style of local residential buildings, explored the reasons for the weakening of local architectural style, and specified the signifi cance of promoting local style of the living environment. By studying the infl uence of local natural environment and humanistic environment on architectural style along the northern foot of the Qinling Mountains, the paper explored the expression of regional culture in residential buildings, with Xian Garden(Xi'an Yuanzi) as an example, and aimed at giving useful help to the dominant expression of regional culture in modern residential buildings.

Test and Analysis of Indoor Thermal Environment of Urban Heating Residential Building in Hanzhong Area

By testing indoor and outdoor thermal environment of residential buildings that apply 4 mostused heating ways in Hantai District,Hanzhong City,this paper explored the indoor thermal environment conditions of different heating ways,to provide references for choosing a suitable heating way in the local area.

What decarbonized the residential building operation worldwide since the 2000s

Decarbonization in operational residential buildings worldwide has become critical in achieving the carbon neutral target due to the growing household energy demand.To accelerate the pace of global carbon neutrality,this study explores the operational carbon change in global residential buildings through the generalized Divisia index method and decoupling analysis,considering the decarbonization levels of residential buildings at different scales.The results show that(1)most of the samples showed a decrease in the total emissions from 2000 to 2019.Except for China and the United States(US),the carbon emissions in global residential building operations decreased by 7.95 million tons of carbon dioxide(MtCO_(2))per year over the study period.Emissions per gross domestic product(GDP)was the most positive driver causing the decarbonization of residential buildings,while GDP was the most negative driver.(2)Carbon intensity was essential to achieving a strong decoupling of economic development and carbon emissions.The US almost consistently presented strong decoupling,while China showed weak decoupling over the last two decades.(3)The pace of decarbonization in global residential building operations is gradually slowing down.From 2000 to 2019,decarbonization from residential buildings across 30 countries was 2094.3 MtCO_(2),with a decarbonization efficiency of 3.4%.Overall,this study addresses gaps in evaluating global decarbonization from operational residential buildings and provides a reference for evaluating building decarbonization by other emitters.

Indicator system of energy efficient technologies evaluation of residential buildings in hot summer and cold winter regions of China

The related existing energy saving index system of buildings is deficient in direction, index coverage, depth, and technological and economic considerations. Aiming at the deficient existing research and with the advancement of energy saving of buildings in China from northern heating regions to southern hot summer and cold winter regions, selecting residential buildings in hot summer and cold winter regions as the research object, and through much evaluation index reference and repeated demonstrations and the borrowing of literature research home and abroad and relevant energy saving standards, filters and eliminates energy efficient technologies evaluation indexes according to the design principle of index system, the factors influencing the energy saving of residential buildings are evaluated, index system weight is established by adopting analytic hierarchy process, and finally the evaluation index system of energy saving technologies of residential buildings in hot summer and cold winter area of China is established. Each target layer includes five standard layer indexes and sixteen index layer indexes. The standard layer of evaluation index, namely primary indexes, includes the technological, energy saving effect, economic, environmental, and social indexes. The secondary indexes are selected based on the principles of concision, comprehensiveness, representativeness and operability.

Energy-saving Planning and Design of Urban Residential Buildings in Hanzhong Area

Energy-saving design of residential building is an important part of energy-saving architectural design. Planning and design of residential buildings in Hanzhong area should pay more attention to the building orientation, sunshine, summer ventilation and wind resistance in winter and so on, so as to create favorable conditions for energy-saving design of single buildings. The geographical location, climatic characteristics, residents living habits and indoor and outdoor thermal environment situation were analyzed in this paper, and combined with the existing problems of energy conservation in the planning and layout of residential buildings in Hanzhong area. Based on the investigation, this paper drew some conclusions to provide references for the energy-saving planning and design of urban residential buildings in the local area.

Research on Evaluation System of Green Residential Buildings in Cold Areas of Sichuan

With regard to the rapid growth of China’s building area and the increasing energy consumption of buildings, green buildings have become an important issue for balancing economic development and environmental impact. However, the current evaluation systems for various types of green buildings are often unable to achieve a set of standards in practice due to the distinct regional characteristics of each region. Therefore, in view of the regional characteristics of the climate, terrain, ecology, and economic development in the cold regions of Sichuan, it is important to study the evaluation system of green residential buildings suitable for the cold regions of Sichuan. This article focuses on the regional characteristics of climate, topography, ecology, and economic development in the cold regions of Sichuan, and discusses the limitations of the current standards on the practice of green building in cold regions of Sichuan through a sociological questionnaire survey on the comfort of living in the local population. Then from the two dimensions of the advantages of traditional houses and the particularity of national culture, the strategies for the optimization and improvement of the evaluation index system for green residential buildings in the cold regions of Sichuan were proposed. After comprehensively considering the factors that affect the green residential buildings, including the regional characteristics of the cold regions of Sichuan, and the green performance of buildings, local characteristics and ethnic features were included in the evaluation system. The evaluation index system of green residential buildings in the cold regions of Sichuan, consists of 92 three-level indicators. A professional hierarchical analysis software yaahp was used to establish a multi-level hierarchical model between the indicators, and the indicators were compared with each other layer by layer to clarify the importance of the indicators. Based on this, a judgment matrix for each layer was constructed and obtained. The weight of each indicator is accurate, and the scoring mechanism and grading standards are constructed according to it. Through the calculation, the consistency test of the entire model was passed, thereby confirming the scientificity and rationality of the entire evaluation system.

Assessing the adequacy and sustainability performance of multi-family residential buildings in Anambra State,Nigeria

The proliferation of multi-family residential building in Anambra State of Nigeria due to increasing demand without recourse to performance has broughtconcerns about the adequacy and sustainability of this housing type.This study therefore,assessed the adequacy and sustainability performance of multi-family residential buildings in urban areas of Anambra State.The study sampled the opinions of 384 households living in multi-family residential buildings through a questionnaire survey.We conducted data analysis based on 214 responses that were useful for analysis.The study found that internal and building component variables and supporting neigh-borhood variables were adequate,but the surrounding environment variables were inadequate based on Mean Score Index.However,based on Sustainability Performance Index,the occupant sperceived social sustainability performance of the buildings as satisfactory,while environmental and economic sustainability performance were perceived as fairly satisfactory.The Pearson correlation coefficient result further established that adequacy of internal and building component variables was significantly and positively related to the residents'perceived social sustainability performance.Adequacy of the surrounding environmental variables was also found to be positively and significantly related to the residents'perceived environmental sustainability performance,whereas adequacy of supporting neighborhood facilities was found to be negatively and significantly related to the residents’perceived economic sustainability performance.This sug-gested that investors and owners of multi-family residential buildings should direct more efforts towards improving the surrounding environment to supplements other facilities and increase the economic benefit of the renters or occupiers with increasing economic sustainability performance in terms of value for money.

Defects in Concrete Elements: A Study of Residential Buildings of 30 Years and above in Onitsha Metropolis, Anambra State, Nigeria

Building defect is an issue in existing buildings that needs urgent tackling to prevent further problems. This study assessed the defects in concrete elements in residential buildings of 30 years and above in the Onitsha metropolis of Anambra State, Nigeria. Data collection instruments in the study include structured questionnaire, interviews, visual inspection/observations, archival records, recordings, photographs;and non-destructive testing of the concrete elements in an existing building in the study area. The population of this study constituted of the construction registered professionals and the existing buildings in study area. The sample for the study was based on the calculated sample size using Taro Yamani Formula. A total of 158 registered professionals were sampled from the population of 260. The questionnaires were purposively distributed to the registered professionals up to the required sample sizes of 158 and 129 questionnaires were properly filled and returned. The study used the SPSS and Microsoft Excel to analyze the data. The results were analyzed in percentages and figures using descriptive statistics and presented in the form of pie charts and tables. The finding of the study revealed that the causes and effects of structural defects on the concrete elements in existing buildings in the study area according to the rating are;exposed/corrosion of the embedded metals, faulty workmanship, overload and impacts, chemical attack, freeze-thaw deterioration, fire/heat, restraint to volume change. The visual observation revealed that the structural elements are characterized by heavy defects such as deep vertical, horizontal and diagonal cracks, exposed/ corrosion of the embedded metals, spalling of the concrete slabs. The existence of defects in the concrete members led to the low compressive strength of the concrete elements and the structural instability of the existing buildings as revealed by the non-destructive test. The non-destructive test result revealed that most of the tested concrete elements have low compressive strength value and such were remarked poor as they did not satisfy the assumed value. Essentially, the study concluded by recommending that regular monitoring, inspections and non-destructive testing of concrete elements should be conducted on existing aged and defected buildings to detect the structural stability of the buildings;and it is imperative to evacuate occupants from heavy structurally deteriorated and defected buildings since most of them have lost their residual design life span and ability to sustain imposed loads.

The Impacts of Building Regulations on the Thermal Performance and Energy Consumption of Residential Buildings in Riyadh City-Saudi Arabia

Riyadh city is the fastest growing city in Saudi Arabia. The rapid urban growth that happened recently in Riyadh was not based on the traditional urban planning principles, which have been established and applied for the city development process. The imported building regulations have created a new urban structures and street patterns. The contemporary urban form in Riyadh city is based mainly on traffic and economic consideration with the neglect of environmental dimensions. This research aims to examine the impacts of building regulations on the thermal performance of residential buildings in Riyadh city, with the ultimate goal of establishing planning guidelines that consider the environmental conditions of the city. The methodology adopted for achieving the aim of this study consists of two phases. First, the literature related to building regulations development in Riyadh, as of 2018, was reviewed. Second, buildings energy simulation was conducted to examine the thermal performance of the typical current status of residential building blocks in Riyadh city, and then several changes to building regulations were made to investigate their impacts on the thermal performance of buildings. The results showed that the impacts of Riyadh building regulations on the thermal performance of residential buildings differ across the evaluated cases. The ratio of building height to street width, urban block street orientation, and building orientation are the main factors affecting thermal performance of buildings within urban block. The study also concludes that adjusting the ratio of building height to the distance between buildings could have a significant impact in reducing cooling loads. This study will help policy makers, planners and designers to investigate the shortcoming in the current building regulations.

Intelligent System Application to Monitor the Smart City Building Lighting

A smart city incorporates infrastructure methods that are environmentally responsible,such as smart communications,smart grids,smart energy,and smart buildings.The city administration has prioritized the use of cutting-edge technology and informatics as the primary strategy for enhancing service quality,with energy resources taking precedence.To achieve optimal energy management in themultidimensional system of a city tribe,it is necessary not only to identify and study the vast majority of energy elements,but also to define their implicit interdependencies.This is because optimal energy management is required to reach this objective.The lighting index is an essential consideration when evaluating the comfort indicators.In order to realize the concept of a smart city,the primary objective of this research is to create a system for managing and monitoring the lighting index.It is possible to identify two distinct phaseswithin the intelligent system.Once data collection concludes,the monitoring system will be activated.In the second step,the operation of the control system is analyzed and its effect on the performance of the numerical model is determined.This evaluation is based on the proposed methodology.The optimized resultswere deemed satisfactory because they maintained the brightness index value(79%)while consuming less energy.The intelligent implementation system generated satisfactory outcomes,which were observed 1.75 times on average.

Investigating the Problems and Proposing Solutions for Rural Residential Buildings in Northwest China

With the increasing income of the rural population in Northwest China,people’s sense of happiness and gain is also increasing.However,the improvement of housing conditions is lagging behind the increasing income levels.In recent years,the government and owners have paid much attention to this issue.The local government has successively issued relevant guidelines and policies to encourage owners to reconstruct their houses and improve their housing conditions.Before improving housing conditions,the existing housing problems must be identified.In order to have a comprehensive and in-depth understanding of the problems of rural residential buildings in Northwest China and to propose corresponding solutions,90 representative rural residential buildings of three provinces in Northwest China have been selected for investigation,and mass data have been obtained.Upon analyzing these data,it has been found that there are problems in five aspects of rural residential buildings in Northwest China:architectural style and functional space layout,energy utilization and dissipation,design,construction,as well as structural safety and seismic measures.Valid solutions are proposed to address these problems,which can also provide a reference for the government and enterprises engaged in the architecture,engineering,and construction(AEC)industry in rural areas.

Application of Green Building Design in Residential Buildings

In recent years,with the rapid development of the world economy,the environment and resources have been seriously damaged,and the global climate is changing quietly.People began to pay more and more attention to the protection of environment and resources.In the process of building residential buildings,the construction industry also needs to strengthen the application of green building design,so as to achieve the purpose of green environmental protection.The author makes an in-depth research and analysis on the characteristics of green building design,and puts forward the effective strategies for the application of green building design in residential buildings,hoping to help improve the green environmental protection of residential buildings.

Potential application of radiant floor cooling systems for residential buildings in different climate zones

A radiant floor cooling system(RFCS)is a high-comfort and low energy consumption system suitable for residential buildings.Radiant floor systems usually work with fresh air,and their operating performance is affected by climatic conditions.Indoor and outdoor environmental disturbances and the system’s control strategy affect the indoor thermal comfort and energy efficiency of the system.Firstly,a multi-story residential building model was established in this study.Transient system simulation program was used to study the operation dynamics of three control strategies of the RFCS based on the calibrated model.Then,the performance of the control strategies in five climate zones in China were compared using multi-criteria decision-making in combination.The results show that control strategy has a negligible effect on condensation risk,but the thermal comfort and economic performance differ for different control strategies.The adaptability of different control strategies varies in different climate zones based on the consideration of multiple factors.The performance of the direct-ground cooling source system is better in Hot summer and warm winter zone.The variable air volume control strategy scores higher in Serve cold and Temperate zones,and the hours exceeding thermal comfort account for less than 3%of the total simulation period.Therefore,it is suggested to choose the RFCS control strategy for residential buildings according to the climate zone characteristics,to increase the energy savings.Our results provide a reliable reference for implementing RFCSs in residential buildings.

A study on carbon emission calculation in operation stage of residential buildings based on micro electricity usage behavior:Three case studies in China

Along with the improvement of social productivity and living standard,residential buildings generate a growing portion of carbon emissions,especially during the operation stage.However,energy use behaviors are usually ignored in carbon emission calculation.This study focuses on calculating carbon emissions during the operation stage for residential buildings based on the characteristics of energy use behaviors in different regions.Firstly,we investigated energy use behaviors in dwellings across three cities in China:Xi'an,Shanghai and Fuzhou.Then,we established calibrated carbon emission models and optimization models with different green building measures for residential buildings.The results of this research reveal a significant disparity between the energy usage habits of residents in different climate regions.The carbon emissions of residential electricity bills in Xi'an,Shanghai and Fuzhou are 13.6 kgCO_(2)/(m^(2)·a)(excluding central heating),29.3 kgCO_(2)/(m^(2)·a)and 17.2 kgCO_(2)/(m^(2)·a),respectively.Equipment carbon emissions account for 32.2%-64.1% of the total.In comparison to the model based on internal standard setting,the accuracy of the models using actual internal has improved by 25.9%-37.4%.The three-star green building methods have the highest carbon reduction rate among different star buildings,the emission reduction rates are around 30%.This study's findings are useful for carbon emission calculation and green building design of residential buildings in the future.

Eco-sustainability Assessment of Building Projects Based on Eco-footprint

The life-cycle eco-footprint computing model of building projects was established in the study. It contained the eco-footprint in 4 aspects during the lifecycle: consumed energy, consumed resource, emitted carbon dioxide and produced solid waste. Space efficiency of life-cycle eco-footprint index was proposed and used to assess the eco-sustainability of building projects. Then, the eco-footprint and ecosustainability of 4 different structure types(brick-concrete bungalow, multi-storey brick-concrete, multistorey steel-concrete, high-rise steel-concrete) for residential building in severely cold areas were investigated. The results indicated that: 1) Compared with bungalow, high-rise building with relatively smaller shape coefficient and window-wall ratio had higher eco-sustainability; 2) For the buildings with the same storey, shape coefficient and window-wall ratio, steel-concrete building had higher eco-sustainability than brickconcrete building; 3) High-rise steel-concrete structure had the greatest eco-sustainability during the 4 different bui lding structures, so it was more suitable to promote.

Occupancy of rooms in urban residential buildings by users in cold areas of China

Occupancy is used to represent the movements and locations of users among various zones of buildings,and it is the basis of all other daily energy consumption behaviors.This study investigated eight families in cold areas of China based on occupancy measurements obtained in four main rooms,i.e.,living room,bedroom,kitchen,and bathroom.In particular,we analyzed the duration of user occupancy and hourly mean occupancy,and characterized their regular and random features.According to the results,we developed an event-based occupancy model using an inhomogeneous Markov chain,where the rooms were modeled and daily events were divided into three categories according to their randomness.We established a new method for conversion between event characteristic parameters and a transition probability matrix,as well as an overlap avoidance method for active events.The model was then validated using real data.The results showed that the model performed well in terms of two evaluation criteria.The model should improve the accuracy of simulations of occupancy.

Chinese Unit Neighborhood Planning Strategies: A Case Study of Beijing

Chinese unit residential buildings can be understood as a flexible urban element, and theintroduction of its concept changed the urban structure of China. In this study, starting from the constraintsof contemporary planning contexts by Chinese historical units, the categories of historical Chinese unitresidential buildings were analyzed, and how spatial order and social ties has made Chinese units becomea common framework within which collective living takes place, how does the political strategy of theChinese government creates and constructs a particular form of spatial order in each example of Chineseunit residential buildings, and the impact on the daily life of the urban population were studied. Finally,how social relations, politics, and economic strategies confront and interact within Chinese unit residentialbuildings was explored.