With reference to the same, the prompted design considerations vary with existing structures, contextual typologies, and nature itself, but the most prominent of all is the location of study and build. Below listed are 10 design considerations an architect must make while building in tropical climates.
The field of architecture, for any layman, would be to build a shelter that provides maximum protection from the elements and is composed of hospitable spaces; and theoretically speaking, the said being the core of the field is irrefutable. For an architect, however, to recite the same expectations into a physical form while considering the demographics, aesthetics, meteorological linearity, and accompanying complexities call for the evaluation of a greater sphere of study called ‘climate-responsive architecture’.
Often referred to as ‘climatology’, it is to study the various climate-based influencing factors on our living conditions, particularly under the heads of seasonality, sunlight, rain, wind and humidity of the target construction site, for maximal dialogue between the structure and its surroundings, in particular, the climate. With reference to the same, the prompted design considerations vary with existing structures, contextual typologies, and nature itself, but the most prominent of all is the location of study and build.
Below listed are 10 design considerations an architect must make while building in tropical climates:
1. Sun Study
For a tropical zone, the kind with peak temperatures touching 30 degree C and diurnal variations being as much as 20 degrees C; to study the sun and daylight, its solar radiations along with the energy analysis is pivotal if one plans to segregate the external spaces, interiors, and the light-sensitive spaces while including the characteristic passive design elements such as mutual shading and adaptability to the seasonal locus change of the sun.
For a hot, windy and often, humid environment, the form is one of the primary considerations for passive design when the objective is to provide superlative thermal comfort to the user and protection of both, the living spaces and the external areas. ‘Compactness’ and ‘Perimeter to Area Ratio’ are two proven methodologies for optimal design in terms of combat against thermal gain, orientation along sun paths, and ease of access of sunlight wherever necessary on the premises. Demanding compact buildings and levied with minimal compromises, inward-looking buildings with interior courtyards for the creation of cooling areas are necessary to minimize the heat gain and when clubbed, the volumetric effect for grouped cooling in massive buildings is another avenue to explore in urban design.
The orientation of a building being majorly influenced by the varying amount of solar radiation falling on different sides of the building at different times of the day is another passive design strategy concentrated into the design along with the form, the aim of which is to encourage clustered arrangements for heat absorption and shading opportunities. Besides sun orientation, another factor to look at is the orientation of the building along with the directions of the prevailing winds for optimum cross-ventilation and cooling of the structure.
Being the determinant of breathability of a building primarily through the exchange of air, openings are critical in a building but the location and size of which vary with the geographical targets. Irrespective of the same, however, it is to be made sure of that the wind entering the house is not passing over hot surfaces and that the openings are large and operable yet manageable when it comes to rain, insects and other gears of nature; all considered during the meticulous placement of the openings along wind channels and behind tree buffers for alignment with the wind orientations and even sun orientations to limit the daylight entering the structure.
To limit the heat gain, access to daylight and its entry through the openings, shading devices are essential environmental controls that greatly reduce the need for mechanical heating and cooling systems. The architect has to choose between external and internal shading devices focusing on keeping the mean radiant temperature of the building low, also achievable through the coherent formation of solar envelopes for self-shading and natural flora and its buffers.
To further limit the entrapment of heat and entry of solar radiations into the building through the openings, proper window performance is of utmost importance since windows incur 20 to 30 times more transactions of heat in a structure than the walls. The glazing in windows traps the heat and increases the mean radiant temperature of the building which in turn stimulates the internal temperature and imbalances the conditional nature of the utility spaces which are in fact, heat-sensitive centers of a building.
Planning or zoning of a building involves prudent thought applied in terms of room-by-room layouts, consideration of different seasons and times of the day the spaces are used the most extensively and better defining the spaces as primary or auxiliary in relation with the former two. The architect must exploit the climatic advantages of the spaces accessible in the overall plan and even ideation of transformability of spaces through the day and night for segregation of areas that have higher internal radiant loads and areas with active requirements for conventional cooling.
Of the three primary spaces in a house, namely the external, the internal, and the light-sensitive spaces, the former two are common to every house and hence, require attention in terms of ingress of light during the seasonal flux and the overall vertical and horizontal zoning schemes developed. The light-sensitive spaces, exclusive to museums, natatoriums, etc, which do not need direct sunlight have to be well planned in terms of positioning and detachment to eliminate the risk of direct exposure to the natural elements.
9. Constructional Elements
While building structures with high thermal capacity for optimal heat gain and retention would be ideal, such a setting fails in a tropical climate. In fact, buildings built in low thermal capacity and lightweight construction are ideal. That paired with the principles of heat transfer, the ceiling must be kept at the same temperature as the other surfaces, i.e. a literal reflective surface, for which a double ceiling constructed above the spaces under the influence of solar radiation suffers immense decrements in heat gain.
10. Thermal Mass
Thermal Mass of a material is its ability to absorb and store heat, and for a climate as hot and humid as the kind found in the tropical zones, the denser thermal mass material used, the better; all due to its ability to absorb heat just as fast as it releases it. The statement entails using appropriate levels of shading, ventilation, and insulation while keeping in mind the mass color as well.
Climate Responsive Architecture, as mentioned, is an entirely separate sphere of study that extends beyond just architecture and it is going to expand farther beyond the mentioned heads because of its necessity in cities, the urgency of its immediate application, and a creative basis for innovative solutions. The ideation, in fact, stems from the changing climatic conditions of the world and the detachment of the urban lifestyle from the architecture of this sort, the sort that is essential in our lives as it has been for centuries, as can be seen in vernacular architecture, as can be witnessed dwindling from today’s modernized take on functional spaces and in particular, a home.