One housing developer is shying away from conventional construction materials and methods in order to build homes which keep cool naturally, thus using less energy, reports MICHELE LIAN. 

IT IS just past two in the afternoon in Bukit Senggeh, Malacca, but the unsheltered concrete slab beneath our feet feels only slightly warm, as it would just before sunset.  

We are at the building site of the Green Acres Orchard and Farm Resort, where 12 single and double-storey holiday resort-style houses are being constructed. The walls of the uncompleted bungalows are also cool to the touch despite the searing heat.  

“These walls are heat-resistant,” says Lincoln Lee, executive director of Value Yield Sdn Bhd, the project developer. They have been constructed using “autoclaved aerated” concrete bricks, which have air bubbles to slow down the rate at which heat travels through them.  

Lincoln Lee says the ‘autoclaved aerated’ concrete bricks he uses helps to keep houses cool.

Lee explains that heat travels in a straight line. So the denser the material, the faster it will travel. The bubbles make the bricks less dense. 

The bricks are used along with old tyres, lightweight plastic sheets and an ingenious ventilation system to build what Lee calls Smart & Cool Homes. Together, these features work to keep the temperature inside each house between 25 and 28°C. 

“It is six to eight degrees cooler compared to the temperature outside, whereas in most brick and mortar houses, it is two to four degrees warmer than that,” says Lee. 

To achieve this cooling effect, he incorporates the various materials and methods into the structure of the house. 

“It’s a complete system, from the foundation right up to the roof. The envelope of the building is very important because heat travels to cold spaces. As long as there’s cold, heat will travel.” 

The foundation of the house is made of multiple layers of tyres placed under plastic polypropylene sheets and wire mesh, which are filled with concrete. Lee says the plastic makes the foundation water-proof, so construction is unaffected by weather. This also renders the house termite-proof, he claims. 

“Tyres are fantastic absorbers of heat. At the Formula 1 races, the cars travel at about 360km per hour. When the driver jams on the brakes, the friction generates heat of about several thousand degrees Celsius, but the tyres don’t burn. 

“When they are placed under the house, they prevent heat from the ground from warming the house. And when the sun shines on them, they absorb about 80% of the heat.” 

Lee says he has no trouble sourcing for tyres because motor repair workshops are more than happy to get rid of them. “Tyres are not biodegradable and very expensive to recycle so disposing them is a huge problem,” he adds. 

And because the tyres are free, they help bring down construction costs by about 20% for a terrace house and up to 30% for a bungalow.  

The houses in Green Acres comprise a built-up area of between 1,653sqft and 1,790sqft and cost RM320,808 and RM338,808 for single and double-storey units respectively. 

Keeping cool 

To prevent heat from coming in from the roof, Lee has placed a ventilation gap in the roof to move hot air out and cold air in.  

“Most houses have an attic temperature of about 50°C because heat gets trapped there, but with this ventilation gap, it’s only about 30°C.” 

The cool interior of the houses makes them energy efficient as air-conditioning will not be needed. This can easily shave RM150 off the monthly electricity bill, says Lee, whose wife Lee Su May – a physicist and energy management specialist – developed the Smart & Cool Homes technology. 

This house in Malacca was renovated to incorporate the Lees’ Smart & Cool technology.

He adds that the bill for each household should come to RM40 to RM80 per month without air-conditioning, which translates to a savings of 80% of the family’s energy usage. 

To keep the houses at a constant temperature, Lee says it is best that windows are kept closed during the day and left open at night. “This ensures cool air goes in and stays there. And because the ‘thermal envelope’ is good, heat doesn’t seep in and build up during the day.” 

Another cost-effective feature of the Smart & Cool Homes that also cuts down on resource wastage is the lack of formwork, particularly those made of wood and steel, which support the house’s structure. The upper floors are supported by corrugated beams which are strong yet light, so up to 50% less steel, wood and concrete are used compared to a conventional house. 

Lee adds that the aerated bricks, which are also much lighter but just as strong as regular bricks, are easier to handle, cut and mend. 

Combined, these features make the construction process faster and less labour intensive. And because less conventional materials are used, there is less trash at the building site. Some of the materials Lee uses are sourced from other countries, but most are made here. 

The houses are built using a modular construction method which involves putting pre-cast pieces together much like the way one would with a Lego construction set. 

“It is easier to build compared to the conventional method. In fact, building a Smart & Cool Home is idiot-proof. We need just five workers who take about two months to build each house, whereas a regular house would take about nine months and 20 workers to complete.” 

Green living 

Lee, 44, was only 20 years old when he took over his late father’s construction business. As time went by, he realised major flaws were being incorporated into Malaysian houses – the materials used to build them trapped heat, making them unbearably hot to live in. 

“Brick and mortar houses were introduced by Westerners and the Chinese. Because they live in cold climates, they allowed the house be heated up during the day.  

“Bricks and concrete absorb heat and warm the house up at night so they save on heating. But it doesn’t work in our climate. Even so, we have been making this mistake for a long time.” 

Lee wanted to build houses that were cooler inside and reduce the wastage of construction material such as concrete, steel and wood. He travelled extensively to learn how houses were built in other countries. In Germany, he discovered the autoclaved aerated concrete bricks.  

After six years of research and experimentation to determine which materials would serve best as the house’s ‘thermal envelope’, Lee and his wife came up with their Smart & Cool Homes technology. 

To prove their technology was fact, not fiction, they worked with researchers from Universiti Technologi Malaysia, who carried out tests on three experimental homes in Kampung Chuah, Malacca – one timber, the other brick and mortar, both of which were fitted with air-conditioners, and a Smart & Cool home. 

The verdict? The timber house was several degrees cooler than its brick and mortar counterpart, but both were unbearable to live in without air-conditioning.  

“In a brick and mortar house, the temperature inside remains as high as 33°C at 1am even though the outside ambient temperature has dropped to as low as 26°C,” says Lee. 

The Lees themselves will be moving into their own Smart & Cool Home in Bandar Tasik Kesuma in Semenyih, Selangor, sometime this year. Their home will serve as a model for their home-grown system.  

To enhance its energy-efficiency, they plan to install photovoltaic cells to run the house on solar energy. He estimates that it will cost about RM25,000 to set up solar panels that will provide enough energy to run an entire household.  

Of the 12 units at Green Acres, eight have been sold. “Our buyers are professionals aged between 38 and 58 years.”  

Lee has licensed the Smart & Cool Homes system to other developers, who plan to work on individual housing projects in Kuala Lumpur. 

“There is a demand for such houses in Kuala Lumpur because the people there understand our concept and the need for such houses.”