By Dr Dany Perwita Sari
In the new normal, we continue our daily routines more or less but with health-oriented approaches. As such, many aspects of our lives have to be redefined—the way we work, commute, shop, define spaces in our homes, and so on. For architects and designers, the top priority in designing a residential space is now to promote occupant’s health and wellness, by incorporating Green building features such as open areas and gardens, exploitable rooftops, and optimal natural light and ventilation, etc.
Before the pandemic, a house was no more than a space to reside and recharge, but since the work-from-home scheme was introduced, urban houses are now multifunctioning as offices and classrooms. New standards, therefore, need to be set according to the situation.
This commentary proposes traditional architecture designs—which often capitalise on locality to create sustainable indoor thermal comfort—as an alternative approach to increase occupant’s wellness in the new normal. Two important elements of vernacular architecture that could be integrated into a modern residential building are the layout and the envelope design.
The design of the traditional building is based on several best practices for sustainable architecture, primarily aimed at reducing heating loads. As a case study, we can take a look at the traditional houses Indonesia. The spatial analysis in my past research showed that for 90 years, from 1920 to 2018, although the traditional house has always been changing, especially its façade, the spatial organisation remains the same, summarised as follows:
- In the past, there were three entrances to respect hierarchy and social status. Modernisation and limited land use have now reduced the number of entrances to only one.
- The reception space for guests is the most important element. Even though the area has since shrunk, it is still maintained to this day to display the community’s welcoming character.
- An inner courtyard has always acted as a bridge between the main house and the side house (for the housekeeper).
The question is then to contextualise this vernacular concept in terms of modern living. In a metropolitan city, an inner courtyard is a luxury because land is expensive. One design solution for this is by using an open layout.
OPEN-LAYOUT DESIGN FOR SINGLE HOUSE
For a single-family house, one solution is to create an open-air atrium. Figure 1 shows the proposed design. This type of house is normally one-storey high, with two bedrooms, a combined living and dining room, a bathroom and a kitchen. The small atrium in the centre of the building becomes the focal point, with all rooms facing it.
A modern house designed with a vernacular concept such as this could be a good solution for one-story residential buildings. The natural ventilation in the building will not only reduce costs, increase thermal comfort and improve air quality, but will also enhance the well-being of the occupants.
OPEN-LAYOUT DESIGN FOR APARTMENT BUILDING
An open layout with a balcony could also be a solution for high-rise residential buildings. Figure 2 is a sample of a typical family house in Taiwan using an open-plan design in a rectangular layout. This plan gives a suﬃcient ventilation that is essential for maintaining comfort through the months of hot and humid weather.
Design B1 is a basic rectangular design with an overhang and a side fin at the window to control sunlight. This design could be a solution for an apartment unit without a balcony. To maximise cross ventilation and daylight, the living and dining room could be made unpartitioned.
The second design (B2) is a rectangular design layout with two units on each side (south and north), with a corridor running along the façade. This design lends a balcony to every unit. The third design (B3) is probably the most optimum because with angles, users get more privacy and daylight. This design allows more comfort for residents that need to remain indoors for longer periods, such as during a movement control and work-from-home scheme.
A strong characteristic of the Southeast Asian vernacular architecture is the naturally ventilated and elevated floor (see Figure 3). This appears to have a strong impact on the indoor air movement. Cross ventilation is when openings in a certain construction are arranged on opposite or adjacent to walls or roof, allowing air to enter and exit.
The system allows constant changes of the air inside the building, and considerably reduces the internal temperature. This not only improves thermal comfort but also reduces energy consumption.
In my research to investigate the wind movement inside the prototype house as shown in Figure 4, I conducted a Computational Fluid Dynamics (CFD) simulation to observe the wind-driven ventilation behaviour and the temperature of the buildings. I noticed that natural ventilation and the raised floor provided thermal comfort inside the house.
The flow patterns show that the raised floor and the horizontal fin on the roof can reduce the heat stored in the room (see Figure 4) by maximising the indoor air movement. The temperatures under the floor and the horizontal louvre near the glass window were low, whereas the temperature at the roof area was high. This indicates that the wind flows from the horizontal louvre to the open ventilation on the roof.
To validate the simulation, we created a prototype residential house called Ecohouse (Figure 5) that utilised vernacular design. Aside from the raised floor and stack ventilation in the gabled roof configuration, natural materials were used. The house is located in a suburban near Great Jakarta area, and observations were carried out during a dry season.
The outcome of the observation was in line with the simulation—a lower temperature and maximum airflow. Also, compared to a typical modern residential house, the analysis results show that these strategies lead to a 26 per cent reduction in energy consumption (see Figure 6).
The importance of sustainable architecture has become increasingly evident during the pandemic. A well-designed home ventilation system moves humid air out of the building, increasing outdoor air exchange, and minimising the risk of airborne or aerosolised transmission.
The presence of biophilic elements such as plants, vegetation or water; the use of natural materials like wood; as well as maximised daylighting in interior spaces can positively impact health and well-being. Traditional home designs have always featured transition spaces such as an inner courtyard that addresses spatial hierarchy. These features are not prioritised in urban architecture where land is scarce, but now, architects may find revisiting/readapting this concept worthwhile.
About the author:
Dr Dany Perwita Sari is a postdoctoral researcher at the ISAAC Lab, Architecture Department, National Taiwan University of Science and Technology (NTUST) and junior researcher at the Research Centre for Biomaterials Indonesian Institute of Sciences (LIPI). Architect by education, her research experience includes traditional houses, comfort and energy efficiency, wind turbine system and climate change adaptation.