Protect buildings and communities from heat
News of El Nino has loomed large since 2026 began, with forecasts suggesting that it could intensify into a “super” El Nino that may push global temperatures to new highs.
El Nino, Spanish for “the Little Boy”, refers to the climate phenomenon resulting from unusually warm ocean surface temperatures in the central and eastern Pacific Ocean.
La Nina, in contrast, is characterised by unusually cool ocean surface temperatures in the same region.
Malaysians have been warned that the El Nino is expected to peak between November and January, bringing higher temperatures, prolonged dry spells and reduced rainfall. These conditions could trigger water shortages, fires, haze and lower agricultural productivity.
The Malaysian Meteorological Department has forecast that temperatures in the country could climb to 40°C early next year.
The instinct may be to stay indoors and turn up the air conditioning, but how can we truly protect our buildings from the effects of extreme heat?
While there are various strategies to reduce indoor temperatures, experts say they must be considered holistically. Only by addressing these interconnected factors can we create buildings that are climate-resilient and energy-efficient.
Fundamental strategies
There are five fundamental strategies for designing an energy-efficient building: orientation, shading, daylighting, insulation and landscaping, said Prof Dr Lim Chin Haw, research clutter lead for net-zero buildings and cities from Taylor’s University’s Faculty of Innovation and Technology.
For the first two, orientation refers to how a building is positioned in relation to the sun’s paths, while shading refers to the use of hoods to protect windows or other openings from the sun.
Daylighting, however, presents a challenge as allowing more natural light can also bring in heat.
“The glazing industry has already produced spectrally selective glass, which blocks infrared radiation and allows a narrow band of daylight to come into the building.
“Another is low-emissivity glass, which has a special coating to prevent the glass from emitting heat,” Prof Lim explained.
For landed homes, roof insulation is among the most important energy-efficiency measures, he said.
He shared that By-Law 38A of the Uniform Building By-Laws (UBBL) adopts the Malaysian Standard MS 1525 to regulate energy efficiency based on the Overall Thermal Transfer Value (OTTV) and Roof Thermal Transfer Value (RTTV).
U-value measures how much heat transfers through a building material, while R-value measures its thermal resistance.
“Under the UBBL, the roof’s U-value must be below 0.4 W/m²K and anything that is above that is not acceptable, so when developers design the roof, they have to make sure that the whole assembly must be below the threshold.
“Certain local authorities are already enforcing this,” he added.
The impact of landscaping in reducing heat can also be tremendous, Prof Lim said, pointing to Singapore’s Skyrise Greenery scheme as an example of how urban greenery can help mitigate the urban heat island effect and reduce ambient temperatures.
Enhance ventilation
While preventing heat is essential, it is equally important to move hot air out.
In 2012, Prof Lim published a paper on wind-induced natural ventilation tower in hot and humid climatic conditions with fellow researchers from Universiti Kebangsaan Malaysia’s (UKM) Solar Energy Research Institute.
The study demonstrated that the wind tower, which leveraged an inverted airfoil roof geometry design and the Venturi effect, can significantly enhance natural ventilation and indoor air quality in low-wind environments.
It was built on a two-storey building at UKM.
“Our wind speed is typically very low, at about 0.5 m/s, so for this wind tower to work, you need to induce the speed.
“We do that by taking advantage of the Venturi effect to create negative pressure to draw air from below. It pulls the air through the building and then out through the tower,” Prof Lim explained.
The research measured the air changes per hour (ACH), a calculation of how many times the entire volume of air in a given space is replaced completely in 60 minutes. With the wind-induced ventilation tower, the daily average ACH for the experimental house fluctuated between 45 ACH and 75 ACH, compared with 7 ACH without the tower (by simulation).
On improving ventilation for landed homes, Prof Lim recommended incorporating a central courtyard for intermediate units to enhance natural daylighting and ventilation.
Climate-resilient schools
Besides residential homes, schools are another type of building that warrants attention as temperature rises.
Through Program Sekolah Hijau Kebangsaan (National Green Schools Programme), the Malaysia Green Building Council (malaysiaGBC) studied 10 schools in Kuala Lumpur to transform existing schools into healthier, more climate-resilient and ultimately zero-carbon learning environments.
Building surveys, energy audits, indoor environmental quality assessments and dynamic computer simulations were carried out to evaluate the effectiveness of different retrofit strategies.
MalaysiaGBC chief executive officer Mitch Gelber said key priorities are improving thermal comfort, enhancing natural ventilation and air movement, reducing solar heat gain and glare, while maintaining good daylight and optimising energy performance.
“Our building performance modelling indicated that under typical naturally ventilated classroom conditions with the existing ceiling fans, classrooms may be thermally comfortable for only around 47% of occupied hours,” he said.
While some classrooms are equipped with air-conditioning units, closing windows without providing adequate fresh air ventilation can compromise indoor air quality, with carbon dioxide concentrations periodically exceeding recommended levels, he added.
While using curtains reduces direct sunlight and heat gain, this results in reliance on artificial lighting that is less than ideal for teaching and learning, Gelber elaborated.
“These findings reinforce that thermal comfort, ventilation, daylight, glare and lighting cannot be considered in isolation.
“The most effective retrofit strategies address these factors together to create healthier, climate-resilient and energy-efficient learning environments,” he said.
MalaysiaGBC has identified a range of practical interventions, including improving air movement through higher-performance ceiling fans, reducing heat gain through roofs and facades, introducing external shading, optimising natural ventilation, improving daylighting and lighting, and enhancing overall building performance.
“By reducing heat gain and improving air movement, classrooms can remain comfortable for longer while consuming significantly less energy.
“This is a more sustainable and climate-resilient approach because it improves the building’s underlying performance, rather than simply relying on additional mechanical cooling,” Gelbert said.
The next step, he added, is to implement pilot retrofit projects, validate their performance under real operating conditions and use the lessons learned to refine a scalable national framework for upgrading schools across Malaysia.
The National Green Schools Programme is a national initiative supported by the Natural Resources and Environmental Sustainability Ministry, the Education Ministry and the Kuala Lumpur Education Department.
Phase 1 was delivered with technical expertise from IEN Consultants Sdn Bhd and funding from the Danish Trade Council under the Ministry of Foreign Affairs of Denmark and the United Nations Development Programme – GEF Small Grants Programme.
Resilient communities
Similar efforts are unfolding across communities, where residents and experts are working together to address the heat challenge from different angles.
In Melaka, a climate resilience initiative led by Majlis Bandaraya Melaka Bersejarah, the Z Zurich Foundation, Zurich Malaysia and Resilient Cities Network, is tackling indoor heat for residents of Rumah Pangsa Pantai Peringgit.
Through heat sensors installed in over 40 homes, researchers from Nanyang Technological University’s Asian School of the Environment found that indoor temperatures remained as high as 29°C even after outdoor air had cooled, underscoring the challenge of heat retention in dense urban residential environments.
The initiative introduced several strategies, including the application of Dulux heat-reflective paint on the exterior walls, urban greening and heat emergency response training conducted in collaboration with Monash University and St John Ambulance of Malaysia.
The training equipped an initial cohort of 36 participants, including volunteer responders, paramedics and paramedic trainers, with the knowledge and skills to stay cool, recognise heat-related illnesses and respond to cases of heat exhaustion or heatstroke.
Reflective paint
AkzoNobel Malaysia commercial head Craig Tham explained that heat-reflective coatings can play an important role in reducing heat absorption at the building envelope level, particularly in dense urban environments. Building envelope refers to the physical barrier that separates a building’s interior from the external environment. It includes walls, roof, windows and doors.
“Their effectiveness is often strongest when combined with complementary measures such as ventilation, shading, insulation, greenery and thoughtful building design.
“By lowering wall surface temperatures, reflective coatings can help reduce heat transfer into buildings and support improved indoor comfort,” he said, adding that actual outcomes may vary depending on building and environmental conditions.
For its heat-reflective paint products, AkzoNobel’s KeepCool Technology in Dulux Weathershield products uses specially selected pigments and formulation technology to reduce heat build-up on exterior walls through reflecting more solar radiation away from the painted surface.
“Under strong sunlight, conventional exterior paints – particularly darker colours – generally absorb and retain more solar heat, causing wall surfaces to become hotter,” Tham said, adding that laboratory and product tests have shown that it can reduce exterior wall surface temperatures by up to 5°C under certain conditions.
Tham stressed that indoor comfort is influenced by several interacting factors, including ventilation, unit orientation, shading, surrounding urban density and daily weather conditions, and heat-reflective coatings are intended to complement these elements as part of a broader passive cooling and urban heat resilience strategy.
“One advantage of reflective coatings is that they are relatively practical and scalable for existing buildings, making them a useful component of wider urban heat adaptation efforts, particularly in dense urban residential settings,” he said.
