This fortress-like concrete house in Singapore hides a surprise within

Given its fortress-like architecture of tall concrete windows and minimal windows, it is not surprising that when the homeowner’s friends saw it from the outside while it was being built, they likened it to a museum or embassy.

Now that the home for the multigenerational family of a local developer is completed, those who have visited the house marvel at the contrasting sense of openness and abundant nature, thanks to a substantial terraced courtyard in the centre. Spaces and corridors unfold around it, so there is light, breeze and greenery everywhere one looks and ambles.

A perfect imagery is that of a rock where the insides have been hollowed out and filled with a wild garden. “It has a courtyard design where all the interior spaces are organised around gardens in the centre. Limited and veiled connection to the exterior happens at selected moments,” described Alan Tay, co-founder of Formwerkz Architects.

This inward-looking architecture was a response to the “extremities” of the site. The main gate faces the car park entrance of the popular Adam Road Food Centre, while the western elevation fronts the cacophonous Dunearn Road and Farrer Flyover. The latter also suffers from direct exposure to the western sun and lack of privacy from the busy pedestrian walkway along the main road.

Tay mentioned that the honking from impatient drivers trying to find a parking space at the food centre is a constant throughout the day. It is a wonder that anybody would buy this plot.

But the owner did, with eyes wide open about these challenges. He had engaged Tay to design his former homes and had confidence in his expertise on the matter. “He wanted a design that could resolve and rise above these disamenities, tasking me to create a haven of tranquillity amid the surrounding chaos,” said Tay.

The house’s form traces the 1,440-sq-m plot’s trapezoidal shape, pushed to the edge as much as possible to maximise the internal areas. Given the size of the land, even with the capacious courtyard, the built-up area still adds up to a comfortable 1,280 sq m that is contained within a “simple solid concrete form”.

The choice of concrete makes the house look impenetrable. Tay highlighted that it was chosen for its many advantages. “I love concrete. It can do many things. It is a very robust material both as a structure and finish. It is perfect for buffering external noise while creating a comfortable micro-climate within, when deployed appropriately.”

The landscaping as well as filigree patterns on the external facades soften the industrial aesthetic. The idea came about because of the owner’s appreciation of Victorian interiors. Tay said: “He wanted something fancy and unique; we wanted to work with concrete. And so the pattern on the concrete abstracts intricate English lace.”

The patterns come from the plywood formwork used to cast the concrete walls. Tay worked with design-to-fabrication consultancy Superstructure to design the patterns. “Modular variations were derived from computational design based on a diagrid. A CNC machine milled the patterns onto the plywood formworks for the concrete casting,” Tay elaborated.

Some of the fenestrations facing the outside are layered with an aluminium screen; the patterns feature a variation of the same diagrid pattern but are perforated for light and privacy control. Laminated windows keep the noise out.

From the entrance facing Adam Road Food Centre, a driveway leads to the basement housing a garage for seven cars, a guestroom and entertainment areas. Ample space in the basement is given to a garden that opens to the sky with trees rising upward to meet a landscaped deck on the first storey.

The main entrance on the first storey is subtle – a small opening at the corner of the skewed plan, sheltered by a black steel canopy. Past a lush planter, the main door leads to the living room that opens to a grassed terrace overlooking the basement garden.

Standing at this terrace, one can survey the genius of the internal organisation – an exercise in structural acrobatics featuring a fluid circulation loop around the courtyard. Traversing around the house feels unencumbered, as there are minimal dead ends.

On the first storey, the living room and grandparents’ room lead to the service spaces and dining area. Here, a door opens to an outdoor sheltered staircase that scales a concrete wall to the children’s bedrooms on the second storey. The loop continues to the master suite above the dining area before culminating in a swimming pool on the rooftop offering a vista of tree crowns and houses’ roof in the near distance, an oasis far from the madding crowd of the streets.

A straight vertical staircase and elevator in the corner link all the floors directly but given the choice, the outdoor steps provide a more delightful way of transitioning levels. Tay meant for the outdoor staircase as a “shortcut” linking the children’s bedrooms to the dining room.

Walking up and down this path lets one enjoy the greenery in the courtyard as well as sky views. Along this elevation, Tay dipped a corner of the concrete wall so that the verdant treetops of the neighbour’s Eugenia trees peek through. “The slant of this wall also makes the house feel less bunker-like,” he commented.

The assortment of green spaces includes a terrarium-like garden at the western side of the plot. Sliding glass doors separate it from the corridor for practical purposes. Tay explained that while the concrete wall is perfect for sound absorption, it also absorbs the heat from the day and releases it at night “like a battery pack”.

He added: "This enclosed garden buffers against heat, which will be uncomfortable for the interior spaces after dark. So we created a void in the roof where the heat can escape through." The occupants can also open the glass doors when they wish to generate internal cross ventilation.

The landscaping has been carefully designed to create an assortment of garden types. “It presents the reinforcement of two worlds: The external garden surrounding the house that is more formal, minimalist and ordered, contrasting with the vibrant and slightly chaotic neighbourhood; and the internal gardens comprising the main terraced courtyard and the two smaller pocket gardens that employ a richer and more varied planting style,” shared Tay.

One encounters other interesting spaces when moving about the home, such as the voluminous corridor outside the children’s bedrooms. A defect in the concrete wall prompted Tay to add a metal bar on the wall that hides a light trough to illuminate future paintings. A skylight running the length of this space exposes changing weather as well as the dynamic slanting roof. 

Another mesmerising corner is at the terrarium-like garden, where massive concrete surfaces rising several storeys provide a vertical stage for the play of light and shadow. Rain falling through the void in the roof adds to the theatrics of nature.

The entire architecture is conceived as a monolith, with the concrete walls rising to meet a sleek metal roof. The origin of the concrete house takes a page from the Brutalist architecture style that started in the 1950s in the United Kingdom and that has become trendy of late. Yet, its sensitive appropriation for the local context and delightful spatial manoeuvres make it an entirely original.