The house enjoys relatively low electricity consumption thanks to a mixture of passive and active strategies, such as cross ventilation, landscape screening, large overhanging eaves and plentiful energy-saving fans that minimise the usage of air conditioning. Solar panels also yield positive energy returns. 

The property features an L-shaped block that shapes a courtyard, enclosed by a privacy wall at the streetside to encourage the spaces to be opened up through the day for breeze and daylight. “We also made most of the spaces one-room deep to bring in natural light and cross-ventilation from both sides. The deep overhanging roof eaves and canopies that shelter terraces and balconies create an optimal and comfortable microclimate for occupants,” says Tan.  

At the house’s rear is an edible garden. “Our strategy of this ‘twin’ garden typology deploys the best of decorative and edible landscaping,” says project architect Allan Tongol. The homeowners have made the habit of turning all kitchen and garden waste (including grass clippings) into organic compost for use in this garden.

The species found on Singapore streets were chosen for this home too as they are typically fuss-free to maintain and resilient in this climate. Instead of a solid concrete wall, a densely grown green fence was grown; this comprises species like Baphia, Podocarpus, Monkey Palms, and Diospyros Buxifolia. Many of these have compound leaves that shed less to reduce maintenance. The shredded compound leaves are also small enough to be integrated back into the earth as compost but do not accumulate water that can cause mosquito breeding.   

Guz Wilkinson’s houses are bucolic havens, with flourishing gardens that are experienced from every part of the house and are deeply integrated with the architecture. Designed by Wilkinson’s namesake firm Guz Architects, the Water Courtyard House is a good example.

“The Water Courtyard House was conceived as a house in a garden in land-scarce Singapore, with greenery and gardens forming the heart and backdrop for the house. The building folds itself around a water courtyard and at the same time, terraces back with roof gardens such that even the bedrooms above always have a view of greenery and roof gardens,” describes Wilkinson. 

The water courtyard is created from the amalgamation of a koi pond and a swimming pool. Island planters with willows and pine trees in the water bodies add further shade. “The water courtyard aids in passive cooling of the house when the windows are open and breezes can blow through,” highlights Wilkinson. The British-born architect designed the cooling ponds in a way that they can be seen from all the rooms, providing visual and thermal respite.

While air-conditioning is provided, the house was designed for passive cooling as much as possible, with the water bodies being one aspect. “The large roof overhangs protect from the sun and the rooms are designed for cross ventilation. The roof gardens are not only nice to look at from the upstairs spaces, but also cool the rooms below through transpiration,” adds Wilkinson. 

The large roof overhangs are important devices to mitigate the heat and glare in hot and humid Singapore. They provide ample shade to terraces, thus encouraging use of these non-air conditioned spaces. When it rains, the interiors are protected but windows can also be left open for natural ventilation. The timber that clads some walls and ceilings is well protected by these roof overhangs, ensuring their durability.

The client of the Forgetting Time House wanted a home that would feel like a sanctuary. He also wanted a large verandah to enjoy outdoor living and dining. Wallflower Architecture + Design’s response was to design the spaces around a courtyard so that everyday activities are intertwined with the outdoors.

“Blending indoor and outdoor spaces to flow seamlessly as one is at the very core of the Forgetting Time House,” says Robin Tan, principal architect of the firm. Landscaping is an integral part of the home, manifested in the courtyard, roof gardens and a sunken garden in the basement. “Extensive landscaping helps to improve the house’s thermal comfort and increases the wellbeing of the occupants,” says Tan. Solar-powered garden lights help save electricity. 

Frangipani trees are planted on every level of the house, visible from multiple rooms and angles. This layering of landscaped terraces reduces the heat and glare of sunlight reflecting harshly off bare roofs. The rooftop gardens also reduce heat on the building’s surface.

The swimming pool in the courtyard is also a sustainable device. “It helps with evaporative cooling, which lowers the ambient temperature and generates convection currents to bring breeze through the ground floor spaces,” says Tan.

Timber is deployed generously, appreciated for its beauty and how it can be harvested responsibly. Comments Tan, “The production process of timber as a building material is more environmentally friendly than the production processes of plastic, aluminium, and steel. Due to timber’s thermal insulation properties, it reduces heat gain and cooling load, thus making it ideal for façade cladding and sun screening.”

It was imperative that the house employed plenty of passive architecture strategies to prevent heat gain and promote cross ventilation. Tan employed thick masonry walls with cavities that have good thermal mass, hence providing insulation against heat transference to the interior. 

“In our tropical climate, most buildings and households spend a disproportionate amount of electrical cost on air conditioning. A well-designed layout, carefully planned openings, sufficient overhangs, and adjustable sunscreens make the house extremely liveable and eco-conscious,” Tan says. Every room and space in the house, including the serviced zone in the basement, is cooled by cross ventilation, convection and ceiling fans. 

Despite facing a busy five-lane thoroughfare, the House of Trees offers respite for its occupants. Designed by Lim Shing Hui of L Architects, it employs a facade of plants and trees that block the view and noise of the traffic, as well as give the occupants a beautiful view to look out to when there is actually none.

A pair of siblings and their families live here in a pair of semi-detached houses that Lim designed to look like one singular building. “The architecture is sustainable in that it has many design elements that address problems of heat, ventilation, and energy consumption. The green facade helps to shield quite a lot of the western sun, which is hotter and more unbearable than the morning sun,” Lim explains.

Fuss-free maintenance adds to the vertical landscaping’s longevity. An automated irrigation system is employed and the plants are fed with slow-release fertilisers that only require a feed every quarterly. 

Lim also selected species that minimises looking after. “Generally, this means plants and trees with big leaves that do not shed easily, and roots that do not grow aggressively such that they may choke the drainage or break through the planter boxes,” she explains. Some examples are plant species that include the Monstera, hibiscus Tiliaceus and Diospyros (persimmon tree). 

A second sustainable strategy was to carve out an internal courtyard, which is shared by both houses. “To have a comfortable indoor environment is to encourage air movement within the house. The courtyard, open to sky to enhance ventilation, achieves that. It’s a very simple passive cooling strategy that also brings in natural light, hence reducing the need for artificial lighting [deep in the plan],” Lim shares.

These passive devices, as well as the abundance of greenery, follow biophilic principles that harmonise the occupants with natural patterns. “These simple, low-tech solutions are often the best, from a long-term perspective. They help create human comfort while reducing energy consumption. We try as much to create comfortable interior spaces without having to depend on air conditioning all the time,” says Lim.

Architecture, she believes, should aim for timelessness and this is not just about making buildings beautiful. “When they continue to be relevant, people will preserve them, and this act of preservation is the best sustainable approach in my opinion,” she says. 

Dubbed Vertical Oasis, this house by HYLA Architects has recently been awarded the Gold Green Mark Certificate given out by Singapore’s Building and Construction Authority (BCA), a rare achievement for a private residence in the city-state. Among its eco credentials include the use of solar panels to generate electricity, as well as energy efficient fittings and cross-ventilated rooms that reduce the reliance on air conditioning.

Read more: Home tour: A ‘faceless’ semi-detached house in Singapore with a hidden garden

Going beyond these technical aspects, the property is a verdant haven that provides comfort and privacy for its owners. Its central courtyard is cleverly designed to be hidden from view from the main street. It’s only upon entering the abode that visitors catch sight of the glorious double-volume courtyard within.

A koi pond and swimming pool flank the lofty indoor-outdoor area of the house, adding to its restful look. An intricate trellis creates shadow play on the party wall and the water features.

HYLA founder Han Loke Kwang expounds on the detail that went into the trellis design: “Firstly, because of the height of the courtyard space, the scale of the trellis members have to be appropriate. Secondly, the spacing of the members and pattern was carefully detailed so as to bring the optimum level of light to the space. And finally, the trellis support’s unique design makes it appear as if [it is] just ‘floating’ in the space.”  

Read more: Home tour: A minimalist Singapore house with amazing treetop views

Environmentalism is a big part of local architect Sharne Sulaiman’s design ethos. “The design must remember its origins, only bringing to its habitat something more beneficial,” he says. This is the approach he took to designing his family home. “It responds to the local climate by reinterpreting vernacular architecture through a modernist lens. The house centres down on its true essence—being at one with nature,” says Sharne. 

Lush landscaping on the ground floor and attic terrace, which Sharne dubs the Skygarden, helps to reduce temperatures in and around the house. “I specified native plants since they are adapted to and thrive in local rain and sunshine. Furthermore, native species bolster local ecology through pollination and food supply. The house’s high plant density attracts lots of wildlife. In fact, birds love the Skygarden so much there are at least four nests built in the mini jungle,” he explains. There is an automatic watering system but it is turned on only during the driest months of the year to conserve water. 

On the roof, 38 solar panels generate more than enough energy to power the house. “By offsetting the consumed utilities with the electricity sold back to the grid, the utility bill is reduced to almost nothing,” says the architect. There is also a solar tube water heater and EV charger.

“The house is one that speaks of topicality,” he highlights. Despite the eco mechanisms, the house’s sustainability “truly comes from a rigorous design to reduce water and energy usage.” This translates to extended roof eaves that protect spaces from rain and sun. Ventilation gaps and monsoon windows help ventilate the house even when it rains, reducing the reliance on air-conditioning for cooling the home. The lush planting and a reflection pool, which recycles rainwater collected from the roof, help with this as well, creating a cool microclimate around the house. 

Lastly, the material choice also helps to create a sustainable house. “Robust fins of regionally sourced Balau timber modulate light into soft vertical strips that warm interior spaces. As a tropical wood, this wood is particularly resilient to termites and sits comfortably with the wildly varying equatorial climate,” says Sulaiman. 

Read more: Home tour: An architect’s eco-conscious bungalow in Singapore with artistic influences

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