The residence of architect Chan Mun Inn is a net zero energy home. This means that he does not pay any electricity bills.
Located in Kota Damansara, Petaling Jaya, 38Mews is where he and his wife – and their 10 cats – live.
A net zero house is a house that produces as much electricity on-site as it consumes over a period of one year.
30Mews is designed as a low energy house and Chan achieved this by incorporating specific design features.
On the one hand, the house is completely raised to promote air circulation while its windows are designed and positioned to facilitate cross ventilation and natural lighting. The roof and walls are also well insulated while the overhangs provide shade.
Rainwater is collected from its entire sloping roof in a tank on the ground floor to water the plants and trees. Solar panels counter the consumption of electricity, half of which is used to recharge his hybrid car.
The house is a good example of sustainable design, which can be defined as building and living in a way that ensures the long-term health of mankind and our environment.
Nowadays, with a greater awareness of sustainable living, many people are looking for home designs that harm the environment as little as possible and consume little energy.
âSustainability in design can be divided into active and passive design. The passive part is to find ways not to use energy, so we need good insulation and a good understanding of how the tropical climate works and how the house fits into the tropical landscape, âhe said. architect Lee Cherng Yih, founder of FormZero.
âThe active part is how to save and use less energy. But the third part, difficult to quantify, are the practices of the owners living in the house.
âIf they turn the air conditioning on full blast all the time, then it’s not sustainable.
âWe always first discuss with the homeowner their lifestyle and the degree of comfort and ‘uneasiness’ they can accept when designing a home. There are certain drawbacks to a sustainable lifestyle that we have to come to terms with, âhe said.
Lee gave an example of one of his projects called Window House in Kuala Lumpur.
âInside, there are no windows in the house. At first I was not sure if the customer could accept this, because mosquitoes and birds could fly.
âBut today they have come to accept it. They love the good ventilation and yes birds and mosquitoes come in, but they’ve learned to live with the design, âadded Lee.
Chan, director of Design Collective Architects, said almost all of his company’s projects feature solar panels and net energy meters with SEDA (Sustainable Energy Development Authority).
Net energy metering is a system in which a utility company pays you for excess electricity produced by your solar panels.
However, Chan added that solar panels are still not cost effective at the moment.
âIt depends on how much the owner wants to invest in the net metering system, because the ROI still takes a long time, around eight to ten years,â he said.
Chan highlights a key factor in sustainable design: wall and roof insulation.
âThe exterior walls should be double brick cavity walls so that when the sun hits the outer layer is warm but the inner layer stays cool. This reduces the amount of heat that reaches the interior.
âThis type of wall incurs additional costs, but it offers good insulation. Even without air conditioning, interiors are cool. And even if you use air conditioning, it takes less energy to cool the interiors because it is already cooler, âChan explained.
The other part is the roof structure, he added.
âThe old terraced houses have almost no roof insulation. Therefore, the heat enters directly.
Lee said the biggest challenge is tackling the comfort of air conditioning.
âPeople always think that if their house is well ventilated, they will have a cool house. No. You can’t compare how cool air conditioning is.
Chan added, âI think the idea of ââgood ventilation is this: you can cool the inside until it is close to the outside temperature.
âThe yard is a good design element, but unfortunately many Malaysians tend to cover it up. The old terraced houses had courtyards but people put a roof over them. But yards cool a house very well, allowing hot air to come in and out.
As architects, Chan and Lee hope more people will truly embrace the principles of sustainable living.
âSustainable living requires a change in lifestyle. Hope more people will understand this and not just want a sustainable design for fun.