Residential Outdoor Spaces And Thermal Stress: Courtyard Design Approach To Thermally Enhance Outdoor Spaces In Single-Family Houses In The Desert Climate Of Riyadh

Abstract

The typological shift of single-family houses in Riyadh during the 20th century has negatively impacted the inhabitants. The shift from attached houses with courtyards to detached houses with setbacks created houses with poor outdoor spaces that are unsuitable for the desert climate and a lack of visual privacy between neighbors. The impact expanded further after the nationalization of this typology with municipal regulations to other cities without considering regional architecture or climate differences. Therefore, the main objective of this thesis is to revise the related municipal regulation of the mandatory 2-meter setback on houses and urge adopting attached houses with multiple courtyards as a proven typology with more advantages. The thesis aims to emphasize the significant improvements to the single-family houses in Riyadh from adopting attached houses with multiple courtyard outdoor spaces as an alternate typology that is more satisfactory in house space planning, spaces visual privacy, and exterior thermal performance. The underlying objective of the thesis is to create continuity in Saudi architecture by reviving outdoor courtyard spaces and attaching house concepts from traditional regional architecture into the contemporary urban fabric of Riyadh, and influencing the revival of other regional architectural principles. Additionally, the thesis aims to evaluate the impact of climate categories on the courtyard’s thermal performance. The thesis’s contribution expands the current knowledge with insights on the performances of outdoor spaces in the desert and temperate climates, focusing on thermal comfort, direct sun, and incident radiation in residential architecture. The thesis’s contribution also expands the current practice by promoting assessment methods for municipal regulation using algorithmic-aided simulations. The hypothesis asserts that courtyard and multiple courtyard typologies in single-family houses in Riyadh improve outdoor thermal comfort experienced by inhabitants and reduce exterior thermal stress on buildings. Riyadh was selected as the primary context in this thesis for its influence on the typological shift and its recent prominent growth in many aspects as the capital and largest city. Therefore, the historical context of Riyadh with the traditional regional Najd architecture was approached in exploring practical solutions to contemporary single-family houses and Saudi architecture progression. The methods utilized in the thesis include a literature review of related works, personal communication, field data collection for existing cases, creation of designed cases, performing environmental analysis using algorithmic-aided simulations, and comparing the analysis results through multiple correlations. The existing cases were selected as courtyards with different layouts and locations to help understand the climate impact on the space. Findings of thermal comfort analysis in the existing courtyard cases in Riyadh and Barcelona conveyed a more substantial impact of the climate over the courtyard characteristic. For testing the hypotheses, the designed cases were created as a setback, courtyard, and multiple courtyard houses in contemporary Riyadh’s urban block. Findings of thermal comfort, direct sun, and incident radiation analyses in the designed cases proved more satisfactory thermal performance for the multiple courtyard typology, then the single central courtyard, and finally, the detached setback typology. Finally, the attached houses with multiple courtyards typology is more promising as a new concept over the others for single-family houses in Riyadh. Furthermore, the typology provides more flexibility in space planning than a single courtyard and ensures privacy between neighbors and within the house zones.