Breathing Walls and Living Homes: The Tropical Power of Clay

Introduction

Imagine a house that cools itself, resists tropical heat, and blends into the land it stands on – this is what clay makes possible.

Across cultures and continents, clay has been used for millennia to build homes that breathe, regulate temperature, and connect people to their environment. In today’s climate-conscious world, this humble material is making a comeback – not as a relic of the past, but as a blueprint for the future.

What is Earthen Architecture?

Earthen architecture refers to building techniques that use natural soil-based materials such as clay, silt, sand, and straw – either raw or slightly processed – to form walls, floors, and even roofs. Common methods include adobe blocks, rammed earth, cob, and wattle-and-daub systems (UNESCO, 2011).

These techniques have existed for over 10,000 years, with archaeological evidence of mudbrick structures dating back to early settlements in the Middle East and North Africa (Getty Conservation Institute, 2011). While estimates vary, studies suggest that up to one-third of the global population in developing countries still lives in earth-based dwellings (UNESCO, 2011). However, more recent data indicates that this figure may have decreased to around 8–10% due to increasing urbanization and changing building norms (Marsh and Kulshreshtha, 2021).

Thermal Comfort: Nature’s Air Conditioner

Earthen materials, such as clay, possess high thermal mass, enabling them to absorb heat during the day and release it slowly at night. This characteristic helps stabilize indoor temperatures, reducing the reliance on artificial cooling systems. For instance, a study assessing the thermal performance of earthen buildings in tropical climates found that such structures can maintain indoor temperatures that are 2–5°C lower than the external environment, enhancing occupant comfort without energy-intensive cooling methods (Wang, Zhang and Li, 2020).

Further research indicates that rammed-earth buildings can guarantee specific comfort performance in high-temperature weather without the use of air conditioning, particularly on lower floors, highlighting the material's effectiveness in passive cooling strategies (Fernandes, Silva and Almeida, 2023).

Humidity Regulation & Indoor Health

Clay's hygroscopic properties allow it to absorb and release moisture, contributing to a balanced indoor humidity level. This natural regulation can mitigate issues related to mold growth and poor air quality, which are prevalent concerns in humid tropical climates. A recent study highlighted that earthen walls effectively moderate indoor humidity levels, creating a healthier living environment and reducing the need for mechanical dehumidification (Muntari and Windapo, 2021).

Additional findings suggest that clay materials have a positive effect on the rapid adsorption and desorption of air moisture in the interior of buildings, further supporting their role in maintaining indoor air quality (Liuzzi et al., 2018).

Local Availability & Low Environmental Impact

One of the greatest advantages of clay as a building material is its local abundance. In most regions, including tropical zones like Palawan, suitable clay soil can be sourced directly from the land itself – reducing the need for long-distance transport and costly imports.

This not only lowers construction costs but also dramatically reduces the embodied energy of the building – that is, the total energy used to extract, produce, and transport materials. Compared to concrete, steel, or even fired bricks, earthen materials have a significantly lower carbon footprint (Morel et al., 2012). They are minimally processed, often require no industrial inputs, and can be reused or returned to the earth without harm.

Moreover, the use of local clay fosters community engagement, traditional knowledge exchange, and income opportunities for local workers. This supports a circular, place-based economy rather than dependence on globalized, energy-intensive supply chains.

Resilience, Repairability & Longevity

While often seen as fragile, earthen buildings can be incredibly durable – if well designed and maintained. Many traditional clay structures in Asia, Africa, and the Middle East have lasted for centuries. In tropical climates, the key is protection: wide roof overhangs, raised foundations, and proper drainage prevent erosion from heavy rains.

Clay buildings are also highly repairable. Small cracks or weather damage can be fixed with the same material they were built from, using simple tools and local labor. This stands in contrast to modern concrete buildings, which often require complex repairs or costly demolition when cracks or structural problems appear.

In a tropical setting prone to typhoons, earthquakes, and flooding, flexibility matters. Earthen structures can absorb movement and withstand extreme conditions when combined with reinforced natural frames (Guettala, Abibsi and Houari, 2006). Their natural fire resistance is another benefit in hot, dry seasons.

Why We Chose Clay for Our Project in Palawan

For us, clay isn’t just a building material – it’s part of a broader philosophy. We chose clay because it allows us to build in harmony with the land rather than against it. It reflects our belief that architecture should respond to climate, support local communities, and use what the earth already offers – with care and responsibility.

Our project in Palawan uses clay sourced from the site, shaped into forms that support both beauty and function. In doing so, we’re not only reducing our ecological footprint – we’re investing in a tradition that has lasted thousands of years and still holds answers for the future.

References (Harvard Style)

 Fernandes, L., Silva, A. and Almeida, M. (2023). Thermal and Humidity Performance Test of Rammed-Earth Buildings. Buildings, 13(9), p.2235.

 Getty Conservation Institute (2011). Earthen Architecture Teaching Guidelines. Los Angeles: The Getty Conservation Institute.

 Guettala, A., Abibsi, A. and Houari, H. (2006). Durability study of stabilized earth concrete under both laboratory and climatic conditions exposure. Construction and Building Materials, 20(3), pp.119–127.

 Liuzzi, S., Rubino, C., Stefanizzi, P. and Petrella, A. (2018). Hygrothermal properties of clayey plasters with olive fibers. Construction and Building Materials, 158, pp.24–32.

 Marsh, A.T.M. and Kulshreshtha, Y. (2021). The state of earthen housing worldwide: how development affects attitudes and adoption. Journal of Building Engineering, 42, p.102482.

 Morel, J.C., Mesbah, A., Oggero, M. and Walker, P. (2012). Building houses with local materials: means to drastically reduce the environmental impact of construction. Building and Environment, 36(10), pp.1119–1126.

 Muntari, M.Y. and Windapo, A.O. (2021). Clay as Sustainable Building Material and its Benefits for Protection in the Built Environment. IOP Conference Series: Materials Science and Engineering, 1144(1), p.012044.

 UNESCO (2011). Earthen Architecture: World Heritage Earthen Architecture Programme. Paris: UNESCO World Heritage Centre.

 Wang, J., Zhang, Y. and Li, X. (2020). Energy performance of earthen building walls in equatorial and tropical cli

mates. Energy Efficiency, 13, pp.735–750.