1. Viridian House - AADA 2024

Trace Design + Build is delighted that our project, Viridian House, has been shortlisted in Asia Architecture Design Awards 2024 (AADA 2024) for the category of Asia’s Best Residential Architecture Design.

Viridian House is one of the ten on the shortlist which includes projects from Singapore, Malaysia, Indonesia, China, India, Thailand and Vietnam. With this year’s theme “Emerging Asia”, AADA aims to celebrate the ingenuity and imagination of architects and designers who are shaping the future of the continent. The recognised projects showcase the perfect balance between modernity and tradition, innovation and sustainability, creating spaces that resonate with the essence of Asian culture and identity.

Situated in the heart of Bukit Timah, the Viridian House with a Gross Floor Area (GFA) of 1,457.76 sqm, emerges through a screen of swaying bamboo trees—a hidden gem within Singapore’s exclusive Good Class Bungalows. We were tasked to transform an aged Balinese-themed structure into a Modern Minimalist Tropical house.

2. How the idea started

The original building featured a Balinese themed bungalow with a 824 sqm footprint, which allowed our architects to borrow key structural and architectural elements for our proposed design. We opted to retain over 80% of the original building’s structure, and 50% of its architectural finishes. This A&A (Addition & Alteration) approach helped minimize the carbon footprint of construction works, while retaining a semblance of the building’s original character. 

Our Tropical Minimalist concept combines modern architectural elements, minimalistic principles and tropical aesthetics for a property that connects living with nature. A definitive feature of the facade are its traditional pitched roofs modernized by accompanying elements such as timber ceilings, aluminum sun screens, and fair-faced concrete columns. From a planning perspective, we emphasized open spaces with ample cross ventilation to minimize the need for air-conditioning (a perennial problem in Singapore). This is exemplified in the Main Living space which opens to the garden courtyard on one end, and to a salt-water swimming pool on the other.

Our design philosophy for Viridian House is rooted in climate responsive architecture that seeks to minimize the footprint of construction works and its ongoing usage. By opting for an A&A approach instead of a rebuild, we estimate emissions avoidance of at least 1,526 metric tons CO2e into the atmosphere. Our attention to cross-ventilation, open spaces, and apt usage of sunscreens and landscaping also helps the homeowner to live more sustainably with reduced power usage. The installation of solar panels on the property has helped the homeowner effectively offset their electrical usage, with excess electricity occasionally sold back to the grid.


3. Complying to the “Build Less” approach

Gross Floor Area (GFA) for Viridian House equates to 1,457.76 sqm. For a rebuild of a house of this size, a typical estimate is for approximately 2,180 metric tons of carbon dioxide (MTCO2e) to be emitted through embodied carbon in superstructures (inclusive of Scope 1 and 2). This represents the lion's share of emissions involved in the construction process, but omits emissions involved in the non-structural aspects of a project.

In commitment to the "Build Less" mission and our ethos of sustainability, we employed an Additions and Alterations (A&A) approach for Viridian House, retaining approximately 84% of structural elements from the original build. After factoring allowances for wastage and non-avoidable preliminary activities, we believe that 70% of emissions avoidance is a conservative estimate for this project (equivalent to 1,526 MTCO2e).

4. Differentiation between other GCBs in Singapore

While Modern Tropical builds are relatively common in the upscale market in Singapore, we find that there is an opportunity for a minimalist slant to that approach. Viridian House was built to modernize the estate while minimizing environmental impact, leveraging its ample landscaping to lend privacy and character to the house. This integration between nature and living spaces is suitable for clients seeking privacy and understated luxury.

Over 80% of the house’s structural elements and 50% of the house’s architectural elements were retained in this A&A build, which proved technically challenging from a design, engineering and construction perspective. Opting for this approach is highly differentiated for the residential sector in Singapore, which often sees such an approach only for conserved shophouses and buildings. This helps to minimize resource wastage in the construction process, while mitigating costs for the homeowner.

Conservation of the building’s original pitched roof tiles was especially important to us, as it also reflects a by-gone era of Singapore buildings that uniformly used such methods. Appropriate treatment was used to refresh these roofs, including a repainting and re-waterproofing to ensure that it integrated well with the building’s modern elements. Where possible, other architectural elements including ceiling finishes and timber floorings were refreshed for continued usage.

The house is also unique in its deliberate intent to practically minimize the usage of air-conditioning within the household (especially within Singapore’s tropical climate). Strategic usage of vertical screens offers a dual purpose of sun shading and privacy without compromising natural light and air circulation. Cross ventilation was thought out for all key spaces within the property, including the main living, dining and primary bedrooms. High double volume ceilings in the Main Living also ensures good airflow, along with extended ledges across the property to mitigate direct rain or sunlight. These designs mitigate heat buildup while promoting ample air circulation within the house, enhancing the overall environmental performance of the structure.

From a design perspective, one indulgence allowed by the architect and homeowner was the incorporation of an indoor waterfall and green wall terrace. This was done to amplify the Tropical Minimalist concept and bring outdoor nature indoors. 

The residence also harnesses solar-power energy for its electricity consumption, with 190 panels (77.90 kWp system) installed on its pitched roofs. This, when complemented by our design with strong natural ventilation, has allowed the homeowner to be self-sustaining for several months of the year, with excess electricity sold back to the Singapore grid.

5. Functionality of Viridian House

Intended as a haven from the bustles of city living, Viridian House was designed for an understated lifestyle with particular attention to wellness and entertainment. The residence comprises distinct zones, with its primary quarters catering to familial living and interactions, and a separate, dedicated entertainment wing to accommodate formal gatherings and entertainment activities.

The main quarters were planned to create an open and continuous relationship with the living room, terrace and dining room. This configuration offers an open view of the indoor waterfall and green feature wall, as well as a direct viewpoint to the decking and salt-water swimming pool. Wellness related amenities encompass a fully furnished gym, repurposed from the old layout's living room space. Spa facilities featuring an onsen and an energy efficient infra-red sauna adjoin the gym for ease of use. The second floor houses the bedrooms, and it also features a dedicated library designed for collaborative study and work purposes.

The entertainment quarters offer a more sophisticated atmosphere, featuring a formal living area with a state-of-the-art theater system. The second floor extends the hosting experience with a wine bar overlooking the salt water swimming pool.

6. Other innovations of the project

Our inclusion of vertical screens as a design element serves a dual purpose in Viridian House. Beyond an aesthetic purpose, these screens play a critical role in providing sun shading and privacy. Extended ledges with timber-clad ceilings are also a common feature across this house, which helps to prevent direct rain and sunlight. This, combined with heightened and double volume ceiling spaces, and cross-ventilation planning, contribute to a naturally well-ventilated, and temperature regulated home.

a) Architectural elements

The sauna facility in Viridian House makes use of infra-red technology. Infra-red saunas are designed for efficiency and comfort and use much less energy than traditional saunas because they heat the body directly instead of heating the air around the body, thus making it more energy efficient. As infrared saunas are ready to use in as little as 10 minutes, compared to traditional saunas which take about 30 to 40 minutes to heat up, the sauna is only turned on when in use thus saving more on energy.

b) Sauna facility

Viridian House features 190 solar panels installed with a 77.90 kWp system output on its pitched roofs. This, combined with the design of the house to require low output for air conditioning requirements, helps the house to be relatively self-sustaining across the year. The homeowner has also shared that the house spends less than the recommended level of energy consumption on average.

c) Solar panels

Salt water was chosen for Viridian House’s swimming pool, which is relatively more eco-friendly (less maintenance, corrosion of building materials, less gases emitted), as opposed to traditional chlorine pools.

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d) Salt water swimming pool

More than 700 projects have been submitted via AADA’s official website. The announcement of the winners is anticipated in early June, with the highlight being the awards ceremony set for July 2024 in Bangkok, Thailand.

An insight into Viridian House and its design and build  performance

Shortlisted for 2024 Asia’s Best Residential Architecture Design