Urban Blocks Research Articles

Exploring the Impact of Urban Morphology on Building Energy Consumption and Outdoor Comfort: A Comparative Study in Hot-Humid Climates

Research simultaneously examining building energy consumption and outdoor thermal comfort within urban environments remains limited. Few studies have delved into the sensitivity of design parameters based on building energy consumption and outdoor thermal comfort. The purpose of this study is to investigate the correlations between urban morphological design parameters and performance indicators, focusing on building energy consumption and outdoor thermal comfort (UTCI), across different urban block layouts in hot-humid regions, like Guangzhou. By establishing six fundamental morphological models—three individual unit layouts and three group layouts—the research explores both control and descriptive parameters through extensive simulation studies. Scatter plot visualizations provide insights into the impacts of various design parameters on energy consumption and UTCI, facilitating a comprehensive analysis of trends and quantitative relationships. Additionally, the study conducts sensitivity analyses on design parameters under different layout conditions to highlight their influences on target performance indicators. The findings reveal common trends, such as the significant impacts of plan dimensions and the Floor Area Ratio (FAR) on energy efficiency and outdoor comfort, as well as differential patterns, such as the varying sensitivities of the Shape Factor (S/V) and the Sky View Factor (SVF), across individual and collective layouts. Ultimately, this study offers a nuanced understanding of urban block morphology’s role in creating sustainable, comfortable, and energy-efficient urban environments, providing valuable guidelines for urban form design in hot-humid climates.

Synergistic Impacts of Built-Up Characteristics and Background Climate on Urban Vegetation Phenology: Evidence from Beijing, China

Vegetation is an important strategy for mitigating heat island effects, owed to its shading and evaporative cooling functions. However, urbanization has significantly affected regional vegetation phenology and can potentially weaken the cooling potential of vegetation. Previous studies have mainly focused on national and regional vegetation phenology, but local-scale vegetation phenology and dynamic variations in built-up areas remain unclear. Therefore, this study characterized the vegetation phenology in the densely built-up area of Beijing, China over the period of 2000–2020 based on high-resolution NDVI data using Savitzky–Golay filtering and explored its spatiotemporal characteristics and drivers. The results indicate that the vegetation phenology exhibits significant spatial heterogeneity and clustering characteristics. Compared with vegetation in peripheral blocks, vegetation in central urban blocks generally has an earlier start in the growing season (SOS), later end in the growing season (EOS), and a longer growing season length (GSL). However, the overall distribution of these parameters has experienced a process of decentralization along with urbanization. In terms of drivers, vegetation phenology indicators are mainly influenced by background climate. Specifically, SOS and GSL are mainly affected by temperature (TEP), whereas EOS is mainly influenced by annual precipitation (PRE). Additionally, local environmental factors, particularly the percentage of water body (WAP), also have an impact. Notably, the local environment and background climate have a synergistic effect on vegetation phenology, which is greater than their individual effects. Overall, this study extends the current knowledge on the response of vegetation phenology to urbanization by investigating long-term vegetation phenology dynamics in dense urban areas and provides new insights into the complex interactions between vegetation phenology and built environments.

Discovering urban block typologies in Seoul: Combining planning knowledge and unsupervised machine learning

Urban blocks are fundamental elements of urban form and play an important role in urban development. Identification of their typologies has been a long-standing challenge in urban planning and design. Traditionally, expert-based classification has been used, but recent studies have shifted towards data-driven clustering to achieve better results. However, most studies tend to use only one of these approaches and few integrate both. To address this gap, this study proposes a framework that combines planning knowledge and machine learning to identify urban block typologies in complex urban environments. The framework first classifies blocks based on their size types according to planning regulations and development types. Then, a combined hierarchical and Gaussian mixture model is used to discover clusters with complex feature data distributions. These clusters are translated into block typologies using a semantic naming system and illustrated with representative blocks. Finally, the validity of the results is tested by comparing them with other building features, such as building age. The proposed integrated framework was applied to Seoul, resulting in the discovery of 27 residential block typologies across the entire city. These typologies show significant correlations with the average building age in the blocks. The application of expert knowledge in the clustering method demonstrates higher accuracy compared to conventional clustering approaches. Overall, this framework holds significant potential for discovering urban block typologies that are consistent with planning domain knowledge and provide urban planners and designers with valuable insights into the characteristics of urban block typologies, thereby helping decision-making regarding zoning regulations, urban design, and urban development strategies.

Physics-inspired and data-driven two-stage deep learning approach for wind field reconstruction with experimental validation

Accurate and reliable wind forecasts for urban blocks play a pivotal role in the construction of zero-energy communities by guiding the selection and placement of wind turbines and the aerodynamic design optimization of ducted openings. While relatively accurate wind fields are available based on numerical methods, their heavy computational cost and discontinuity make it necessary to explore an interactive and end-to-end method. In this study, we develop a physics-inspired and data-driven two-stage deep learning approach that can reconstruct complex wind fields precisely. The proposed method integrates a physical feature extraction model of the flow field with a sparse measurement data-driven error correction approach. In particular, a well-designed and well-trained flow field feature extraction model (original model) can preserve salient features of CFD modelling, while data-driven error correction techniques may harvest the uncertainty features and fill the remaining gaps between the original model predictions and the measured data. The proposed method is verified by a measured dataset from a community in Beijing. Experimental validation illustrates that the proposed algorithm successfully accomplishes wind field reconstruction in complex terrains using sparse datasets. We show that the proposed two-stage strategy exhibits significantly improved prediction results over the purely original method, with an average accuracy improvement of 47.17% and a maximum accuracy improvement of 72.59%. Overall, the proposed method delivers the potential in accurate wind field construction and urban wind energy forecasting.

Unveiling the magic of mega-city block environments: investigating the intriguing mechanisms shaping children's spontaneous play preferences.

This study delves into the spatial preferences of children for play spaces within high-density urban block environments, specifically targeting the area of Baihua Second Road in Shenzhen, China. Recognizing the critical role of play in children's development, and the unique challenges posed by dense urban settings, this research employs multiclass logistic regression models and negative binomial regression models to construct a detailed mathematical analysis of neighborhood spatial elements and children's play space preferences. Data was meticulously gathered through both objective observations of 14 different types of spaces within the block, and subjective assessments via children's responses to a series of environment photos, capturing the essence of over 3,000 child participants' interactions and choices. Key findings reveal a pronounced preference among children for soft facility features and visually appealing spatial experiences, suggesting a nuanced understanding of play space needs beyond traditional playground designs. Notably, the study identifies that while cartoon-style designs in play facilities might increase moderate attractiveness, ordinary designs hold broader appeal, indicating a preference for diversity in play space aesthetics. These insights offer profound implications for urban planners and designers, advocating for a child-centered approach in the creation of urban play environments that prioritize aesthetic diversity, and the integration of natural elements. Moreover, the study situates Baihua Second Road as a paradigmatic case, illustrating the methodology and analytical framework applied in addressing the complex interplay between children's play preferences and urban spatial configurations. By incorporating a comprehensive data-driven analysis, this research contributes significantly to the discourse on child-friendly urban design, offering valuable strategies for cultivating inclusive and engaging urban play spaces for children amidst the constraints of high-density city living.

Physical vulnerability of pedestrians under the joint effect of wind and floodwater and its application in urban block flooding: Effects of urban block layout, building form and building array skyline

It has become urgent to formulate the physical vulnerability of pedestrians exposed to the compound hazard of strong wind and flooding in an urban landscape and identify the pedestrian risk characteristics within urban building arrays. In this study, the physical vulnerability of pedestrians subject to a joint effect of wind and floodwater is quantified theoretically based on a mechanical analysis in terms of floodwater velocity, depth and wind speed. Laboratory experiment regarding the instability of a dummy is performed to calibrate this vulnerability formula. The formula is adopted to quantify the pedestrian risk rating within different urban building array configurations in conjunction with computational fluid dynamics simulation, including the urban block layout, building form, and building array skyline. It is found that (i) the reverse wind reduces the area of the extreme instability risk zone of pedestrians but improves the safety zone area in comparison to the forward wind; (ii) in comparison to the determinant layout, the enclosed layout is indeed favorable to pedestrian safety; however, the staggered layout causes pedestrian safety to deteriorate; (iii) either corner modification or a change in building form leads to a large reduction in pedestrian risk; and (iv) For a parallel building skyline array, a low street aspect ratio (i.e., the ratio of building height to street width) yields an increased pedestrian risk when the aspect ratio is smaller than unity; however, a large aspect ratio produces an increased pedestrian risk when the aspect ratio exceeds unity. The protuberant skyline leads to more high-risk zones than the parallel skyline, while a concave skyline does not alter the risk distribution except for the last row of buildings. The ascending skyline configuration leads to a more complex and more uniform risk distribution pattern, while the descending skyline does not change the general risk distribution trend. These results might be referenced by engineers and managers to implement tailored measures (for example, optimizing urban array configurations) for mitigating and reducing pedestrian risk in urban regions.

Urban microclimate differences in continental zone of China

In modern cities, the block geometry and land cover feature directly affect the heat transfer between ground surface and atmosphere, resulting in significant differences of local microclimate. Clarifying this difference will help to accurately predict regional building energy demand and optimize regional layout design. However, existing microclimate research mainly focuses on tropical, arid, and temperate climate regions, leaving continental areas virtually unexplored. To address this problem and clarify the interactions of the urban blocks and microclimate, the combination of the local climate zone (LCZ) scheme and fixed-point weather station monitoring is employed to investigate the variation characteristics of the thermal and humidity conditions of typical urban blocks in continental zone of China. Firstly, sixty-seven typical urban blocks with self-built, national and regional meteorological stations are selected as the object of study, and classified into twelve LCZ categories, according to their inherent features. Secondly, the spatial and temporal variation patterns of the thermal environment indexes of the twelve LCZ types are analyzed and compared. Additionally, correlation analyses and regression fittings are performed between the thermal environment indexes and the urban morphological parameters. The results indicate significant differences in thermal environment indexes among different LCZ types. The mean temperature of built types is 0.72 °C higher than land cover types. The temperature and humidity exhibit a parabolic relationship with height of roughness elements and building surface fraction respectively, while the humidity has strong negatively correlations with the impervious surface fraction and the height of roughness elements.

Empirical Analysis on Influence of Authenticity Perception on Tourist Loyalty in Historical Blocks in China

Tourist loyalty is the key to the sustainable development of tourism in urban historical blocks. This article focuses on exploring the relationship between authenticity perception and tourist loyalty in this context. With this aim, we introduce the mediating variable of tourist engagement and construct a theoretical model of authenticity perception, tourist engagement, and tourist loyalty. Hierarchical regression analysis and bootstrapping were performed on questionnaire data of 287 West Street tourists in Dujiangyan, China. The results of this study demonstrate that both object-related authenticity perception and existential authenticity perception have a significant positive impact on tourist loyalty behavior, with similar degrees of influence. Additionally, the study reveals that tourist engagement plays a mediating role in the relationship among object-related authenticity, existential authenticity, and tourist loyalty. From the perspective of tourist engagement, this article reveals the impact mechanism of authenticity perception on tourist loyalty in the context of historical block tourism, enriches the research on tourism authenticity, and deepens the understanding of tourist loyalty behavior. Furthermore, the results of this study also provide reference for the formulation of sustainable development policies related to tourism in historical blocks.

Modelling urban stormwater and irrigation management with coupled blue-green infrastructure in the context of climate change

ABSTRACT Urban planners must consider stormwater infrastructure to prevent floods, enhance resilience and promote sustainability, ultimately benefiting cities by minimizing damage and fostering sustainable growth. This is leading cities to consider the implementation of urban blue-green infrastructure (BGI) as an integrated approach to stormwater management. An urban irrigation model, blue-green infrastructure irrigation (B-GRIIN), has been developed that incorporates BGI and the possibility of reusing stormwater for irrigation to facilitate the design of zero-runoff urban blocks. Simulations based on rainfall time series, including an extremely dry year, have shown that it is possible to achieve a zero-water balance and provide sufficient water for irrigation by implementing coupled BGI. However, water availability in extremely dry years may limit the full irrigation of all green areas. The results have also shown that the evapotranspiration scaling factor kc has a large influence on the predicted irrigation volume and thus on the overall water balance. The B-GRIIN model makes it possible to couple the rainwater management functions of different BGIs, determine their water requirements and provide sufficient irrigation water. As a result, it can serve as a basis for holistic planning and operation of BGI in order to achieve a zero urban water balance.

Estimation of travel flux between urban blocks by combining spatio-temporal and purpose correlation

Understanding the travel flux between urban blocks is fundamental for traffic demand prediction, urban area planning and urban traffic management. However, the uncertainty of human mobility patterns and the complexity of urban transportation systems usually yield challenges in accurately estimating the travel flux within a city. Thus, we propose a novel travel flux estimation method that integrates traffic flow characteristics (traffic volume and travel time), spatio-temporal autocorrelation, and travel purpose correlation. First, the geographically weighted method was used to model and verify the spatio-temporal autocorrelation of origin–destination flows, whereas the purpose correlation of origin–destination flows was expressed through the function feature vectors of urban blocks. Then, a multi-objective bi-level programming model, according to the generalized least squares method, was constructed to estimate the travel flux between blocks. This was used to solve the problem of accurate estimation of travel flux by combining microscopic traffic flow characteristics with macroscopic spatio-temporal and purpose characteristics. Finally, an empirical analysis of the Hankou district, Wuhan City, demonstrated that in contrast to the existing method, the accuracy of the proposed method for predicting the human travel flux improved by approximately 20%. The estimated results were consistent with the spatial distribution pattern of human travel. Moreover, these results can provide targeted decision support for planning urban spaces, allocating urban resources, and guiding vehicular traffic.

Reframing Different Layers of Morphological Dimension - A Context of Urban Spaces w.r.t Net Zero Energy to Achieve Zero Carbon Emissions

Abstract: The contemporary city presents itself as an urban organism of great complexity, consisting of an increasingly number of elements, systems, dynamics and extracts, which makes their reading an equally complex task. the method of morphological analysis, it is assumed in this context, as an important reading tool of the city, giving order to what is naturally disordered through a classification process of the different elements that structure it –streets,squares, urban blocks,building , plots among others .Specifically, the paper discusses the morphological component of urban design, concentrating on the forms along with configurations of urban centers, as well as current preferences for urban blocks and interconnecting street patterns. Overall, it is concerned with the network of public spaces as well as actual public realm, which is the physical setting or stage for public activity. An important factor in this is one of the key tensions at the core of modern urban design: complexity, conflicts, andsynergies between the requirement for space and movement necessary for economic and social interaction and everyday living. Urban design goals, according to Jan Gehl, should be prioritized in the following order: first it islife, second it isspace, and third it isbuilding.

A Study of the Effects of Historical Block Context on Soundscape Perception

This study aims to explore the influence of spatial functional differences on the overall relationship between soundscape and visual landscape in the context of historical blocks and then propose design guidelines for audiovisual elements. Audiovisual stimulus materials were collected from 11 representative locations in typical urban historical blocks along the southeast coast of China and classified into residential, cultural leisure, and commercial spaces based on their primary function, activity, and visual environment characteristics. An evaluation environment was created in the laboratory using virtual reality technology, and a subjective evaluation questionnaire was administered to 71 volunteers regarding the perception of audiovisual elements and the evaluation of the overall environment. Structural equation modeling was used to elucidate the relationships between sound source perception, soundscape perception, visual landscape satisfaction, and overall harmony of the environment and to compare the effects of functional differences at different locations on the overall relationships. The results show significant differences in the types of perceived sound sources at different functional locations, which makes the sound sources affecting soundscape perception and visual landscape satisfaction different. Residential space is mainly affected by artificial sound and mechanical noise; in cultural and leisure spaces, all three types of sound sources have a significant impact, and only natural sound has enhanced subjective perception; the impact of artificial sound in commercial space is crucial. In addition, visual landscape satisfaction should be prioritized over soundscape pleasure to enhance the overall harmony of the environment. In residential and commercial spaces, reducing artificial and mechanical noise can effectively enhance the harmony of the environment; in cultural and leisure areas, reducing artificial sounds and increasing natural sounds or historical landscape elements can enhance the overall harmony of the environment. The results of this paper provide empirical evidence for understanding the overall relationship between soundscape factors in urban contexts and suggest that place function should be considered an important context when designing soundscapes.

An Estimation of the Available Spatial Intensity of Solar Energy in Urban Blocks in Wuhan, China

Urban form is an important factor affecting urban energy. However, the design of urban form and energy mostly belong to two separate disciplines and fields, and urban energy planning research rarely considers their mutual relationship. The available space intensity (ASI) of solar energy is formed on the basis of energy planning and urban design; the objective of this research is to evaluate the impact of urban form on the ASI of solar energy and to propose strategies for planning of the space that is available for solar energy so as to improve the efficiency of urban energy utilization and achieve sustainable urban development. Methodologically, this study firstly proposes a model to quantify the ASI of solar energy using three indicators: solar radiation intensity (SRI), solar installation intensity (SII), and solar generation intensity (SEGI). Then, we quantitatively calculate the solar ASI of nine types of typical urban blocks in a sub-center of Wuhan City, Nanhu. Correlation analysis and multiple linear regression analysis are then used to analyze the correlation between the form indicators and solar ASI, as well as the degree of influence. The results show that the differences in SRI, SII, and SEGI amongst the nine types of city blocks were as high as 114.61%, 162.50%, and 61.01%. The solar ASI was mainly affected by three form indicators: the building coverage ratio, the average building height, and the volume-to-area ratio. Reducing the building coverage ratio and increasing vertical development at the same time can effectively improve the ASI of solar energy. The results of this study and the established method provide an important reference and rapid calculation tool for urban energy planning and design, reducing the data and time usually required for solar analysis at the block scale.

An experimental and numerical thermal study of a small-scale urban block with courtyard

Courtyards, as integral historical elements in architecture, play a crucial role in shaping the environmental and cultural characteristics of a region. Their global significance lies in their capacity to act as microclimate modifiers, significantly impacting the thermal conditions of their immediate surroundings. This study aims to provide a comprehensive exploration of the intricate thermal dynamics inherent within courtyards, emphasizing the research gap in existing knowledge. In pursuit of this objective, an in-situ investigation was conducted using a reduced-scale model at the Urban Block with Courtyard (UBC) mockup in Tetouan, Morocco. The study used a small scale 1:10 model of an urban block with courtyard, constructed from Oriented Strand Board (OSB) wood. The model was equipped with two single-glazed panels, positioned both within and outside the courtyard, forming the basis of the experimental framework. The outcomes of these experiments were compared with a numerical approach integrated through the TRNSYS 18 software. This approach facilitated the description of thermal, radiative, and aeraulic phenomena at the microclimate scale. The results of the comparative analysis demonstrated a commendable level of concordance. The computed average absolute error in surface temperature for the courtyard walls was found to be less than 1 °C, with an average relative error of approximately 3.5 %. Notably, the developed numerical model showcased efficiency in addressing interoperability challenges associated with diverse analytical tools. Furthermore, the model contributed to reducing computational time compared to Computational Fluid Dynamics (CFD) simulations while maintaining a commendable level of precision in assessing thermal and energy performance aspects. This research contributes to a deeper understanding of courtyard dynamics, addressing a significant research gap and showcasing the efficiency of the developed computational model in architectural analyses.

Research on social ecological evaluation of the spatial form of old urban blocks based on dual probabilistic linguistic term sets

Under the rapid process of urbanization, many early renovated urban villages have also encountered many problems. Due to the rapid development of urban construction and the continuous changes in spatial functions, early renovated urban villages have already encountered problems such as unreasonable commercial distribution, lack of parking spaces, reduced commercial vitality, and commercial activities crowding out affecting the normal lives of villagers. There is a serious contradiction between the need for development and the quality of life of villagers. Due to the fixed nature of architectural space, only by fully understanding the essential morphological characteristics of the space can we find the optimal solutions for different space usage functions, and obtain the matching of the optimal solutions in the existing space requirements. The social ecological evaluation of the spatial form of old urban blocks is a multi-attribute group decision making (MAGDM). Recently, the grey relational analysis (GRA) and CRITIC method has been used to cope with MAGDM issues. The dual probabilistic linguistic term sets (DPLTSs) are used as a tool for characterizing uncertain information during the social ecological evaluation of the spatial form of old urban blocks. In this manuscript, the dual probabilistic linguistic GRA (DPL-GRA) method is built to solve the MAGDM under DPLTSs. The CRITIC method is used to obtain the attributes weights. In the end, a numerical case study for social ecological evaluation of the spatial form of old urban blocks is given to validate the proposed method.

Urban microclimate analysis: residential block morphology impact on outdoor thermal comfort

In many cities, protracted exposure of urban structures to excessive solar radiation and the urban heat island (UHI) phenomenon may cause thermal discomfort for pedestrians in outdoor spaces, particularly in hot-arid regions. This study investigated the impact of urban residential block morphology on microclimate in Isfahan, Iran, using ENVI-met numerical models. The predicted mean vote (PMV) model for residential outdoor spaces was calculated using simulation data for the hottest day of the summer to assess outdoor thermal comfort. Comparison of the alternatives – namely, diagonal blocks, compact linear blocks, continuous curved blocks and dispersed cubic blocks – showed that the microclimate performance of the diagonal type was better than those of the other design options, as the PMV index represented the minimum distance from the ideal thermal comfort range due to a lower sky view factor (SVF) and optimal orientation. The curved blocks performed better in urban open spaces, promoting airflow and reducing UHI, than linear and cubic blocks. The results showed that the PMV index could predict thermal comfort in various urban design patterns and could be affected by the morphology of urban blocks. Variations in building morphology alter the SVF and microclimate parameters, which have an impact on outdoor thermal comfort.

A Scientometric Examination on Performance-Driven Optimization in Urban Block Design Research: State of the Art and Future Perspectives

The study of performance-driven optimization (PDO) in urban block design is essential in the context of architectural form and urban sustainability. PDO focuses on the integrated and comprehensive optimization of various quantifiable performances of buildings, such as solar energy usage, thermal comfort, and energy efficiency. This method aligns urban spaces with sustainable development principles, ensuring they are not only aesthetically pleasing but also functionally efficient. This study explores the existing deficiency in the literature by conducting an in-depth scientometric analysis of PDO in urban block design. Employing science mapping coupled with bibliometric analysis using Python, this study meticulously analyzes the prevailing literature to map out the current intellectual landscape, understand trends, and identify key themes within this domain. This review identifies the key trends, methodologies, and influential works shaping the dynamic field of PDO. It emphasizes the critical roles of computational simulation, artificial intelligence integration, and big data analytics in refining urban block design strategies. This study highlights the growing importance of energy efficiency, environmental sustainability, and human-centric design elements. This review points to an increasing trend towards using sophisticated modeling techniques and data-driven analysis as essential tools in urban planning, crucial for developing sustainable, resilient, and adaptable urban spaces.

Investigating the Effect of Living Walls on Cooling Energy Consumption in Various Urban Microclimates, Building Heights, and Greenery Coverage Areas

With the aim of addressing the significant contribution of buildings to global energy consumption and the growing need to establish a more harmonious connection between humans and nature in urban environments, the concept of green vertical systems has garnered considerable attention. These systems possess the potential to enhance the energy efficiency and environmental sustainability of buildings. This study seeks to explore the impact of living walls on the energy performance of buildings, specifically investigating the influence of a living-walled urban block on the ambient air temperature and its subsequent effect on building energy consumption. By comparing the cooling energy consumption of two typical buildings situated in Shiraz, southern Iran, with varying levels of greenery in different microclimates, we further ascertain the effectiveness of living walls in reducing energy consumption. To conduct this analysis, we employed coupled simulations utilizing EnergyPlus and Envi-met, which incorporated both the outdoor microclimate and the cooling energy consumption of the buildings. The urban block under consideration consisted of 48 three-story buildings (Case A) and five-story buildings (Case B) within a site measuring 120 m × 150 m. Our findings substantiate that the implementation of a living wall system can lower the ambient air temperature by a significant extent, with an average decrease of 1.35 °C and a maximum decrease of 2.25 °C. Consequently, living walls can effectively mitigate the urban heat island phenomenon by decreasing the temperatures of the surrounding buildings. Additionally, our investigations revealed a maximum energy saving of 15%, with microclimate exerting a 4.3% influence on these savings.

Optimizing urban block morphologies for net-zero energy cities: Exploring photovoltaic potential and urban design prototype

Optimizing urban block morphologies for net-zero energy cities: Exploring photovoltaic potential and urban design prototype

Effects of urban vegetation on microclimate and building energy demand in winter: An evaluation using coupled simulations

As an important landscape, the evergreen vegetation is prevailing, even in cold region cities. However, the impacts of promoting vegetation on microclimate and building heating load (BHL) are still inexplicit. This study validated the feasibility of a new-developed coupled model that linked ENVI-met and EnergyPlus, for predicting the microclimate and BHL in winter. The impacts of vegetation configuration changes on the performances of three typical urban blocks in Xi'an, a high-density city in the cold region of China, were then evaluated. When the leaf area index of green lands increased from 0.79 to 4.77 m2/m2, a decrease of 3.27 °C on mean radiant temperature, a decrease of 0.48 m/s on wind speed, and an increase of 0.47 °C on air temperature at the block scale could be observed. To the three blocks, the BHL of thermal zones in the height range of tree canopy increased by 7.16 %, 1.52 % and 3.57 % during a sunny day, and decreased by 2.80 %, 0.55 %, and 0.06 % during a cloudy day maximally. Overall, the evergreen vegetation produced negative impacts on the building energy efficiency of cold region cities. For urban planners, it's advisable to concentrate evergreen plants in high-rise blocks to mitigate such disadvantages.