Astrid Hill home
New wood and fair-faced concrete, which can be reused, are used for the facade of the award-winning house. Photo: The Straits Times

It took Mrs Darani Winnie Tsao four years to design and build her bungalow in Astrid Hill off Holland Road. But she did not mind as long as she could live in an eco-friendly house when it was finally completed last year.

The Shanghai-born 59-year-old, who is one of the directors at Attitude Performing Arts Studio, first discovered the property in 2009.

She was amazed that the previous owners, an elderly couple, had lived there since 1965. The idea of a house that could withstand the test of time resonated with her. 

She was also inspired by the natural landscape of Bhutan on a previous trekking trip there.

In a blog detailing the process of building her home, she writes about her visit to the Buddhist kingdom: "I thought if I was ever going to build a house, it will be a house that is in harmony with nature." 

Darani Winnie Tsao
Mrs Darani Winnie Tsao 

But she candidly admits to The Straits Times that she "had no clue what a green house should look like" when she started on her eco-home.

She put together a team of 15 architects, consultants and engineers from different companies in order to find the best, eco-friendly way to build the house.

They experimented with building techniques and features that would suit the humid Singapore climate. Even the National University of Singapore's architecture students came on board to do feasibility studies. 

The schematic design, architecture and interior of the house, which sits on a 20,000 sq ft plot, was led by Mrs Tsao's brother-in-law and his team. He runs New York-based architectural firm, Tsao & McKown, which is most well-known here for its design of the Suntec City project.

Mrs Tsao's husband is Mr Frederick Tsao, chairman of IMC Pan Asia Alliance, and they have two adult children who live abroad.

The team looked at factors such as the orientation of the house, which sits on a hill; how to counter the humidity and the energy resources they could use.

From a bird's-eye view, the shape of the two-storey house looks like "three fingers spread apart". Each "finger" is long, rectangular and boxy, with the facade clad in new wood and fair-faced concrete, which can be reused if the house is demolished. Next to its more ornately designed neighbours, the house looks unusually simple and covered in lush green walls.

Huge double-glazed windows let in plenty of natural light.

Astrid Hill home
Huge glass windows (above) let in plenty of natural light.  Photo: The Straits Times

Rainwater collected from the roof is channelled into a rainwater-harvesting tank hidden below the swimming pool deck. It is filtered and used for different purposes, such as watering the plants; topping up the swimming pool and the lotus pond; and the toilet-flushing system. 

Whatever overflows from the tank is collected in a bio-retention pond at the base of the slope. A bio- retention pond is one where contaminants and sedimentation are removed from rainwater collected in a shallow depression before it is released into public water sources.

Astrid Hill home
A gravelled drain channels excess rainwater to the bio-retention pond before it is released into public water sources. 

Other green features in the five-bedroom house: an edible garden and solar panels that cover most of the rooftop.

Mrs Tsao is also a strong believer in recycling, so she sourced for old teak for the pool's decking. It has a silvery tinge, showing the material's age, and she picked it as the natural oil in the wood protects it from termites. She also practises composting food waste and leaves.


Astrid Hill home
Green walls by the side of the house greet visitors to the home; and huge glass windows (above) let in plenty of natural light.  Photo: The Straits Times

Clever design has also reduced the need for additional fixtures.

Most of the doors and cabinets have handles that are carved into the wood. Mrs Tsao says: "The design and engineering can help reduce what we need to buy. You don't even need to buy furniture."

For her efforts, the Building and Construction Authority awarded the $7-million house a BCA Green Mark Platinum Award last year.

Even though much work has been put into planning the house's green features, Mrs Tsao is keen to learn more about keeping a house sustainable. She plans to let other architects or students visit her home and use it as testbed for new green features and technology.

Written by Natasha Ann Zachariah for The Straits Times