Courtyard Building Research Articles

Pollutant cross-transmission in courtyard buildings: Wind tunnel experiments and computational fluid dynamics (CFD) evaluation

Courtyards, a historical architectural feature surrounded by buildings, are common in urban housing and residential complexes. These spaces, often open-air and with rooms facing them, are crucial for daylight and natural ventilation. While courtyards are essential for introducing fresh airflow into adjacent indoor areas, the effectiveness of natural ventilation may be compromised due to potentially poor air circulation from limited openings. This raises a significant concern: could the design of courtyards inadvertently facilitate pollutant cross-transmission? Despite a wealth of research focused on airflow within courtyards, the indoor spaces in proximity to these courtyards have often been neglected in previous works, particularly concerning the exchange of pollutants between the indoor and courtyard environment. This research investigates the dynamics of indoor-outdoor pollutant cross-transmission in courtyard buildings, assessing factors like external wind flow patterns and internal pollutant sources. Wind tunnel experiments were conducted to measure internal pressure and CO2 concentration and to validate a computational model of the courtyard with 12 rooms. The validated Computational Fluid Dynamics (CFD) models were used to simulate the dispersion of pollutants from internal rooms under different wind conditions. The results showed that the k-epsilon Realizable model accurately simulated internal surface pressure distribution and pollutant dispersion in the courtyard building. It was observed that when pollutants were released from the downwind east-facing ground floor room, CO2 concentrations in adjacent side rooms on the same floor were significantly higher, increasing from the baseline of 400 ppm and reaching up to 3211 ppm in the north-facing room at a wind speed of 4.51 m/s and wind direction of 0°. Conversely, when pollutants originated from north- and south-facing side rooms, pollutants were minimally dispersed to adjacent rooms. Furthermore, at a wind direction of 45°, pollutants from wind-exposed rooms predominantly dispersed to downwind rooms, with peak concentrations exceeding 2400 ppm in downwind rooms. These findings demonstrate that pollutant dispersion is highly dependent on wind direction and the location of the pollutant source. The study concludes that while courtyards enhance indoor environmental quality through natural ventilation, their design must be carefully considered to prevent unintended pollutant cross-transmission, particularly under varying wind conditions and pollutant source locations.

Reconciling retrofitting with IEQ to maintain energy, environmental and economic performance: A methodological approach for generic office buildings

Office building retrofitting may instigate significant reductions in energy consumption and there is growing recognition that buildings’ energy, economic and environmental performances (the 3Es) must be considered in tandem. This study aims at maintaining the 3Es when retrofitting office buildings towards nZEB standards. A simulation-based methodology was designed consisting of three generic building forms describing common office building geometries constructed between 1952 and 1980 in Egypt; linear, square with courtyard and L-shaped. Each accommodated for open, closed and semi-closed office layouts as recommended in architectural manuals, and was oriented in four directions, giving 36 base cases. A combined retrofitting strategy was applied and both base cases and retrofitted cases were simulated in DesignBuilder using Cairo weather data, which was validated indirectly through real measurements using preliminary simulations that retrieved statistical significance.Results were analyzed for each of the 3Es by comparing base cases to post-retrofitting performances. Results revealed that not all retrofitted cases that demonstrate acceptable environmental performance and/or energy-efficiency are cost-optimal. However, the following patterns were deduced. Square courtyard buildings yield superior performances, and L-shapes tend to perform outside acceptable ranges. Closed plans demonstrate superior energy and environmental performance but poorer economic performance. 17 out of 36 retrofitted cases achieved nZEB, illustrating the potential of implementing nZEB in Egypt. This work may be considered prototypical, encouraging a national office building retrofitting process toward nZEB. However, implications extend beyond the national level, as results may be used to support a kick-off retrofitting programme based on basic office building geometries.

Performance of traditional Chinese courtyard buildings from a sustainability perspective and implications for contemporary green building design

Climate change, resource depletion, and biodiversity decline have prompted the construction industry to seek more sustainable solutions. While high-tech and often high-cost technologies and equipment support progress toward more sustainable built form, the sustainability performance of historical and vernacular buildings should also be reviewed. These buildings may offer advantages that are “hidden in plain sight.” This research focuses on the use of building information modeling technology to model and simulate a historical Chinese courtyard building. The outcomes of the simulation were evaluated using the green building council of Australia’s green star rating criteria to provide quantitative results. At the same time, relevant literature was explored to obtain a qualitative perspective. The final results indicate that courtyard buildings can serve as useful references for contemporary building design and retrofitting. The choice of building materials offers designers effective ideas for designing sustainable buildings. Courtyards can enhance ventilation, cooling, humidity control, light exposure, and connectivity to outdoor areas while ensuring privacy. In developing countries, this approach may be a viable way to promote sustainable development and energy conservation.

Thermal conditions and daylight availability in different zones of courtyard buildings; a study in Iran

ABSTRACT Passive design strategies enhance indoor thermal comfort and reduce energy consumption in buildings located in hot climates. Thus, exploring the various zones of a house’s yard can yield valuable insights for devising a plan that achieves high energy and lighting efficiency. This study examines the climate-responsive design strategies of 20 traditional courtyard buildings in Birjand’s hot and dry climate. These courtyard houses informed modelling a new hypothetical house in DesignBuilder. Two main orientations (45° = NE–SW, and 315° = NW–SE) were used for comparing their impact on indoor air temperature, solar gain and daylight factor across various courtyard zones. The findings indicate that during winter, the interiors of courtyard houses maintain a temperature higher than the exterior, while in summer, they remain cooler than outside conditions. Concerning the influence of orientation on indoor climates, the NE–SW orientation yielded the greatest solar gains for windows in the northern and western zones. Conversely, in the NW–SE orientation, the most substantial solar gains were recorded for windows in the northern and eastern zones. Additionally, the study noted a marginal variation in the daylight factor across different zones of the courtyard houses when comparing the two orientations.

Ventilation Quality Assessment of Dual Courtyard Configuration

Maintaining air quality within building spaces is a challenge under the increased pollutants resources. The optimization of the courtyard building layout toward natural ventilation has emerged as a critical factor in shaping air quality conditions. This study delves into the assessment of outdoor air quality infiltration within a dual courtyard typology characterized by varying proportions and orientations for both the connecting link and openings. To comprehensively analyse air quality within these integrated courtyards, a combination of on-site particle dispersion measurements and flow pattern simulations were employed. The outcomes of this investigation highlight the pronounced impact of atmospheric conditions, particularly wind direction, on the performance of courtyard configurations. The results revealed that dual courtyard provide an approach to address the geometric conflict between thermal comfort and air quality optimization. Even in circumstances with limited flow velocity, the direct connection between courtyards deepens the upward recirculating flow into the courtyard cavity at the activity level. The optimal air quality is attained by planning each courtyard’s upper-level intake and outflow openings, as it provides an evacuation flow out of court cavity and decline the PNC than outside surrounding conditions.

Numerical investigation of evaporative cooling strategies on the aero-thermal performance of courtyard buildings in hot-dry climates

In hot and dry urban environments, courtyards help mitigate extreme heat and influence the urban microclimate. These structures not only provide light and private outdoor spaces but also aid in mitigating the urban heat island (UHI) effect through improved airflow and evapotranspiration. Courtyards, being central open-air areas enclosed by buildings, are crucial in creating opportunities for natural ventilation driven by wind and buoyancy-induced forces, thus serving as a microclimatic regulator. This study investigates the role of courtyards in modulating their microclimate and adjacent indoor areas by integrating evaporative cooling strategies to enhance cooling in these spaces. While numerous studies have been conducted on the role of water bodies in evaporative cooling, the aero-thermal impact on adjacent indoor spaces remains less understood. Addressing this gap, the present research explores the effect of an evaporative cooling system on the wind and thermal conditions within a courtyard and examines different natural ventilation modes, namely, single-sided and crossflow ventilation, in indoor spaces. A computational fluid dynamics (CFD) model, validated against wind tunnel experimental data, was employed to simulate various evaporative cooling water spray configurations. The results reveal complex courtyard microclimates with diverse cooling effects influenced by room orientation and floor level. Specifically, in single-sided ventilated courtyards, water sprays significantly improved the indoor thermal environment, with the average temperature across all rooms decreased by 2.06 °C, and humidity increased by 4.29 %. However, in cross-ventilated courtyards, water sprays' cooling and humidifying effects were relatively less effective. This research underscores the potential of evaporative cooling technology in improving the microclimate of courtyards, with practical applications extending to urban design and architecture. By tailoring cooling strategies to specific courtyard configurations, urban planners and architects significantly improve indoor comfort levels and energy efficiency.

Retrofitting historical buildings with innovative techniques: Double-skin façade and skylights for courtyard buildings

Historical buildings hold significant cultural values but often face challenges in meeting modern sustainability and functionality standards. The aim of this study is to enhance the energy efficiency, occupant comfort and resilience of the heritage stock while preserving its historical significance, by assessing the application of innovative retrofitting techniques, such as double-skin façades and wide skylights for the courtyards’ covering. The first part delves into the concept of retrofitting and the importance of preserving historical architecture, especially in Italy, whose historical centers represent a unique example to be preserved and prepared for future sustainability challenges. The second part focuses on the use of double-skin façades and glazed covers for courtyards, in the retrofitting process, to study the influence that they have on the whole building. It discusses how these techniques can be adapted to suit the unique characteristics of courtyard buildings, balancing modern needs with heritage conservation. A repeatable case study is examined to showcase the successful implementation of these techniques in historical courtyard buildings and to illustrate the practicality of retrofitting solutions while respecting the historical context and architectural integrity of the structures. This research seeks to encourage architects, preservationists, and stakeholders to embrace these innovative techniques for the revitalization of our architectural heritage.

Ventilation and pollutant dispersion in a group of courtyard buildings with a diagonal wind

Ventilation and pollutant dispersion in a group of courtyard buildings with a diagonal wind

The Effect of Courtyard Geometry on Airflow Regimes for Ventilation in Tropical Nigerian Environment

Effective natural ventilation is subject to the ambient wind flow, as well as the conditions of the micro-climate and the geometry of the built structures in the environment. Architects and designers adopt the courtyard concepts for designs in hot tropical climates owing to its unique geometrical characteristics that enable the improvement of airflow required for natural ventilation. This paper presents a review of the airflow regimes within an urban settlement as well as flow regions cultivated when winds interface with courtyard buildings. The impacts of these winds are further studied against different courtyard configurations using schematic analysis based on the H/W ratios, to predict the natural ventilation potentials of various courtyard building types.

Research on the wind environment in an enclosed courtyard: Effect of the opening position, size and wind angle

With the urbanization process in China, outdoor thermal environments are drawing increasing attention, of which comfortable pedestrian height wind environments are crucial for urban outdoor spaces. Few studies have been conducted on the comfort wind zone ratio (CWZR)11Abbreviations: CFD, computational fluid dynamics; CWZR, comfort wind zone ratio; MWSR, mean wind speed ratio; SWZR, static wind zone ratio. models for openings in enclosed courtyards. We quantitatively analyzed the effects of different opening positions, sizes, and wind angles on the wind environment of campus enclosed courtyards via computational fluid dynamics (CFD) simulations, and CWZR models were established for different opening sizes and wind angles. The results are as follows: (1) The opening position, opening size and wind angle significantly affected the outdoor wind environment. (2) Under the dominant wind direction in summer, the cross-opening position better improved the courtyard wind environment than the symmetrical opening. The courtyard CWZR significantly increased with increasing inlet opening size and increased with decreasing outlet opening size. (3) A wind angle from 2° to 47° is the recommended angle for typical courtyard opening types, and the maximum courtyard CWZR occurred at a wind angle of 10°. The study results could guide courtyard building design and courtyard wind environment optimization and enrich the theoretical study of outdoor wind environments.

Outdoor Microclimate in Courtyard Buildings: Impact of Building Perimeter Configuration and Tree Density

As the effects of climate change and urbanisation intensify, liveability and comfort in outdoor spaces decrease. Because of large spaces exposed to solar radiation and low crossing of airflows, courtyard buildings are extremely vulnerable in this regard. However, there are significant gaps in the literature on outdoor comfort in courtyards, especially regarding the effect of border configuration (including gap position and features), as well that of tree density. The study proposes a methodology—to be used during preliminary design—to compare the effect of alternative scenarios for courtyard buildings on outdoor microclimate, varying both the building perimeter configuration and courtyard vegetation layout. A matrix is set to combine the two variables and select relevant scenarios, which are then simulated in ENVI-met focusing on air temperature, wind speed and physiological equivalent temperature (PET). A case study in Bologna, Italy (humid subtropical climate) is presented as an example of the implementation. The resulting outdoor microclimate maps and frequency diagrams are compared and discussed. It emerges that both variables have a role in outdoor comfort: while gap configuration affects air temperature more (up to a difference of 1 °C), tree density impacts PET by up to 2 °C difference. The methodology can be replicated in several other contexts to support the optimisation of courtyard building design from the early stages.

From Poor Buildings to High Performance Buildings: The Spontaneous Green Evolution of Vernacular Architecture

The spontaneous evolution of vernacular architecture mainly relies on the inheritance of architectural traditions and the innovative decisions of occupants, rather than the professional guidance of architects and the promotion of government agencies. This study introduces a new and rapidly developing phenomenon of spontaneous green evolution of vernacular architecture into the professional field, and conducts scientific research on its technical characteristics, system effects, and optimization methods. Based on the phenomenon of roofing of courtyards (CBR) in southern Hebei, we intervene from the professional point of view of architects, make the best use of the situation, and moderately intervene in its scientific development. By re-examining the adaptability of the open and closed attributes of courtyard buildings to specific climatic conditions and living patterns, the performance improvement and potential risks brought by CBR to local vernacular buildings are systematically analyzed, and the improvement strategies and promotion paths of CBR are explored. The research aims to form a relay and interaction between the professional intervention of architects and the spontaneous evolution of folk wisdom, and to explore the sustainable development of vernacular architecture. The findings help to improve the health and comfort of existing vernacular buildings, as well as to contribute to the improvement of rural human settlements.

Phenomenon of courtyards being roofed and its significance for building energy efficiency

Courtyard building is an important type of vernacular architecture, widely distributed in different climate zones around the world. Traditionally, courtyards are characterized by opening to the sky, providing buffer spaces for ventilation and light for the surrounding buildings. However, in Hebei, China, local buildings are showing an evolution trend characterized by the courtyards being roofed (CBR). This spontaneous evolution presents the diversity of CBR technologies (CBRTs), including light-transmitting CBRTs (T-CBRTs) and non-light-transmitting CBRTs (NT-CBRTs). Based on field measurements and simulation technology, the improvement effect of CBR on building energy efficiency (EE) is analyzed, and the EE of different CBRTs is compared. The results show that, T-CBRT and NT-CBRT can reduce the annual total energy consumption of open courtyards by 19.97% and 15.41% respectively without upgrading the original envelope structure. The analysis of the impact mechanism shows that CBRT increases the temperature of the courtyard and the room by improving the solar energy collection efficiency and expanding the heat storage space, which effectively reduces the heat leakage caused by the envelope and ventilation, and shortens the heating time. The light transmittance of the roof material is the most critical parameter affecting the EE of T-CBRT, and the roof height largely determines the performance of NT-CBRT. Multi-layer glass or concrete panels are not the best choice for CBRT roofing materials, and plastic films or polycarbonate sheets with high light transmittance and anti-aging are recommended. CBR is considered as a promising development direction because it can reduce the economic burden of energy consumption for local farmers by improving the EE of buildings.

The impact of building enclosure type and building orientation on indoor thermal comfort ---A case study of Kashgar in China

Gaotai dwellings are the most important representative of dwellings in Xinjiang. It is an important evidence for studying the living customs and architectural features of ethnic minorities. The building enclosure type (BET) and building orientation (BO) are important factors that influence the indoor thermal comfort of the courtyard building. In this research, 20 test scenarios are simulated through field investigation and virtual simulation integrated in the software to grasp the influence of BET and BO on indoor thermal environment. The conclusions are as follows: 1. The higher the degree of building enclosure, the higher the number of comfort hours and the better the comfort. 2. Each BET has its suitable orientation. The best orientation of “T” type is east, the best orientation of “I” type and “L” type is north, and the best orientation of “C” type and “O” type is south. 3. When the optimal BET is combined with its corresponding optimal orientation of the main room, the indoor thermal comfort will be greatly increased (comfort hours in winter and summer will increase by 62.9% and 37.1%).The conclusion of this study can provide flexible design ideas for courtyard buildings to improve the thermal comfort in Kashi.

Towards the new generation of courtyard buildings as a healthy living concept for post-pandemic era

COVID-19 has laid a context for holistic research and practical approaches towards health issues in buildings. This study focuses on one particular residential building type, which is a combination of a modern apartment building with private double-oriented terraces, and a traditional courtyard building. This principle improves several aspects of healthy buildings and contributes to address indoor-outdoor interactions, daylighting, and the use of natural ventilation. The purpose of this study is to determine the factors underlying a particular type of semi-outdoor space within building forms and to explain their microclimatic behavior in buildings. One solid model and twelve porous apartment buildings with different numbers of porous sides, and terrace widths are evaluated using computational fluid dynamics. The k–ε turbulence model is adapted to simulate airflow in and around a four-story building. CFD simulations were validated against the wind-tunnel measurements. Investigations indicated that increasing the number of porous sides reduces the internal mean and maximum ages of air by -15.75 and -36.84%, which means improved ventilation performance. However, it leaves a negative trace on ventilation of the semi-outdoor spaces. Meanwhile, increasing the width of the terraces enhances the ventilation performance by reducing the mean age of air in units, courtyards, and terraces by -20%, -20%, and -9%, respectively.

Qualities and potential of the courtyard building type in Finnish contemporary urban environment

Qualities and potential of the courtyard building type in Finnish contemporary urban environment

Unravelling the impact of courtyard geometry on cooling energy consumption in buildings

At present, the energy used for air conditioning in buildings in urban areas accounts for over 36% of total global energy consumption. Energy efficiency has become a critical factor in the urban planning of cities worldwide. Courtyard buildings in hot cities are a prime example of the approach used in traditional vernacular architecture to mitigate the effects of extreme weather. However, given the challenge of guaranteeing accurate modelling of microclimates within these courtyards, their impact on energy demand in buildings has been routinely overlooked by energy certification tools.This work examines three empirical case studies selected in Seville city (Spain), where temperatures during the summer months are extreme. The case studies selected display distinct geometric variations, and the primary objective of the research is to assess the influence of this geometric factor on the cooling energy demand of the building indoors. To achieve this, a validated methodology combining experimental and numerical data was implemented to evaluate the energy performance of buildings with courtyards. Different simulations were conducted to detect the impact of individual courtyard features. The results show a reduction in cooling demand of 8–18% depending on the geometry of the courtyard. Analysis was also carried out on the influence of the floor level and the orientation of adjacent rooms, revealing differences of 15% and 22%, respectively. The main conclusion of the research is that the use of courtyards as functional devices, paying particular attention to their geometry, is a key factor in the cooling energy demand of buildings.

Research on the influence of courtyard space layout on building microclimate and its optimal design

The inner courtyard is an important transition space for mass exchange and heat transfer between the internal space of courtyard buildings and the external environment. A good layout of courtyard space is conducive to building energy efficiency and human thermal comfort. In the paper, we analyze the impacts of different design schemes of the spatial layout on the microclimate of inner courtyard space using field measurements and numerical simulation methods. The analysis of the measured data presents the main meteorological factors affecting the thermal comfort of the courtyard. The magnitude of the effects is ranked as air temperature, total solar radiation intensity, near-surface air flow rate, and relative humidity. Results of the ENVI-met simulation show that changing the cover of different underlying surface types leads to different microclimate regulation effects in the sense that the temperature and relative humidity in summer drops up to 3.53 °C and 15.59%, respectively and in winter increase up to 3.97 °C and 37.21%, respectively. This paper proposes that lawn ground, marble ground, water surface and landscape tree coverage of 25%, 25%, 50% and 75%, respectively, are suitable design schemes for the inner courtyard space of library.

:Architecture in Ancient Central Italy: Connections in Etruscan and Early Roman Building

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Simulation of Window-to-Wall Ratio for Thermal Comfort of Fully-Enclosed Courtyard Residential Buildings in Kafanchan

The literature has revealed that relationship between the courtyard and the window-to-wall ratio (WWR) is paramount to thermal comfort of fully-enclosed courtyard residential buildings. This study, therefore, seeks to determine the optimum WWR for fully-enclosed courtyard residential building typology for Kafanchan and its environs. The Integrated Environment Solution and Virtual Environment (IES-VE) simulation software was used to simulate five typologies of WWRs for four typologies of room area(s) in fully-enclosed courtyard residential buildings in Kafanchan. The IES-VE software was used for the simulation experiment. WWRs were developed into five models which were simulated to determine the optimum. The results revealed that, WWR4 (window size of 1.44m2) has better air temperature condition in all the room areas than all the remaining WWRs. This suggests that it is the best, followed by WWR3, 2, 1 and 5 respectively. Conclusively, WWR4 is the optimum. However, further simulation studies are required to understand optimum location of windows for improved airflow in the fullyenclosed courtyard building.