For a long time, insulation in Asia was not really part of the building vocabulary. Not as a product, not as a system, and not even as a design question. When we began working with natural building systems and hemp-based construction in Asia around ten years ago, one of the first realizations we had was this: most buildings here are not designed to perform thermally. They are designed to be mechanically conditioned.
We rarely ask how a building behaves. We rarely ask how heat moves through a wall, how a roof responds to summer sun, or how indoor temperature changes across day and night. Instead, we ask which air-conditioner will cool the space and which heater will warm it. Comfort, in this model, is outsourced to machines.
This mindset has shaped not only our buildings, but also our expectations. Houses are judged by how they look—how modern, glossy, and impressive they appear—rather than by how they perform. Very little attention is given to how much energy a building will consume over its lifetime, how stable its indoor temperatures will be, or how healthy its internal environment will remain.
The Missing Concept of Thermal Performance/ Insulation in Asia
Interestingly, if we look back at traditional Asian architecture, we find that insulation in principle did exist, even if it was never called by that name. Thick earthen walls, lime plasters, clay floors, thatched roofs, courtyards, shaded verandas, high ceilings, and cross ventilation all worked together to moderate heat, store warmth, and release moisture. These buildings interacted with climate rather than fighting it. They were designed as climate moderators.
The loss of this wisdom came with the rapid adoption of concrete, thin masonry walls, industrial finishes, and sealed interiors. Slowly, material intelligence was replaced by machine dependence and concept of insulation in Asia disappeared.
Today, most buildings follow a predictable pattern. Thin walls allow heat to enter easily. Interiors become hot. Air-conditioners are installed. In colder months, heaters are added. The building envelope itself is not expected to do much work. This creates a self-reinforcing loop of higher energy demand, larger machines, higher electricity bills, and increasingly overheated cities. Globally, buildings are responsible for roughly one-third of energy-related carbon dioxide emissions, with heating and cooling being major contributors. A significant portion of this energy use is avoidable.
The Emerging Insulation Movement — And the Risk of Choosing the Wrong Materials
Over the last decade, a positive shift has begun. Architects, builders, and homeowners are starting to talk about insulation. People are asking about wall assemblies, roof build-ups, and thermal performance. There is growing curiosity about natural materials such as lime-based systems, hempcrete, clay plasters, hemp fiber, sheep wool, cellulose, cork, and wood fiber. This growing awareness is encouraging and necessary.
At the same time, another shift is happening in parallel. Alongside this interest in building performance, there is a rapid increase in the use of synthetic insulation materials such as EPS, XPS, polyurethane foam, PIR boards, and polyester fiber. These materials are widely available, aggressively marketed, and supported by large industrial supply chains. For many projects, they appear to be the fastest and cheapest route to achieving a stated insulation value.
Yet popularity does not equal long-term wisdom.
Western countries adopted synthetic insulation at massive scale several decades ago. Today, many of those same countries are confronting the consequences: indoor air quality problems, moisture-related failures, mold growth, fire toxicity risks, large embodied carbon footprints, and difficult end-of-life disposal. As a result, there is now a strong movement in parts of Europe and elsewhere toward bio-based insulation materials such as wood fiber, hemp, straw, cork, and sheep wool.
In simple terms, the West is trying to move away from the materials that Asia is just beginning to embrace.
This moment matters. Because if Asia moves from “no insulation” directly into “synthetic insulation,” we are not actually progressing—we are repeating a 50- to 70-year-old experiment whose results are already visible.
Why Synthetic Insulation Creates Long-Term Problems
One of the major issues with synthetic insulation is embodied carbon. These materials are derived from petrochemicals and require energy-intensive manufacturing processes. Large amounts of fossil fuel energy are consumed before the material ever reaches a building site. By contrast, plant-based insulation materials originate from renewable biological sources that absorb carbon during growth. Many natural insulations effectively store carbon inside buildings.
Another serious issue is moisture behavior. Most foam-based synthetic insulations are vapor-closed. They do not absorb moisture and they do not release moisture. When water vapor enters a wall assembly and encounters these layers, condensation can occur. Trapped moisture leads to mold, decay, odor, and loss of insulation performance. The material itself may not rot, but everything around it can.
Fire behavior is another critical distinction. When synthetic insulation burns, it releases dense smoke and highly toxic gases such as hydrogen cyanide and carbon monoxide. In many fires, these gases are more lethal than the flames themselves. Natural fiber insulations tend to char and smolder rather than melting and dripping, and they do not release the same toxic chemical load.
There is also the question of long-term performance. Many synthetic foams shrink, crack, or lose insulating value over time. Laboratory test values do not always reflect real-life performance after twenty or thirty years inside a wall. Natural insulation materials, when kept within appropriate moisture ranges, tend to age more gracefully and predictably.
Perhaps most importantly, insulation is not only about R-value. True comfort emerges from the interaction of multiple factors: thermal resistance, thermal mass, phase shift, airtightness, moisture control, solar design, and ventilation. Many natural building systems combine several of these functions into one material. Hempcrete, for example, offers moderate insulation, significant thermal mass, good phase shift, and excellent moisture buffering. The result is indoor temperature stability with far lower dependence on mechanical systems.
A Critical Choice for the Future of Building in Asia
If Asia chooses a synthetic path now, it is likely that in a few decades we will face the same health, waste, and climate problems already visible elsewhere. At that point, we will attempt to shift toward natural materials. This means we will lose time—time we no longer have.
We are already living with the consequences of modern building practices and short-term material thinking. Climate instability, heat waves, flooding, and resource depletion are no longer abstract concepts. Buildings constructed today will shape environmental outcomes for generations.
The question, therefore, is not simply which insulation material is cheapest. The real question is which materials belong in a regenerative future.
Natural insulation is not about nostalgia. It is not about rejecting technology. It is about choosing materials that work with physics instead of against it, with biology instead of against it, and with climate instead of against it.
Asia has an opportunity to leapfrog directly into bio-based insulation systems, learning from both traditional wisdom and modern building science. If we take this path, we do not merely improve buildings—we reshape the relationship between people, materials, and the planet.
That is the deeper promise of insulation.
