Low-carbon flat reveals life's green alternatives

Nearly all the renewable technologies used in city's first zero-carbon building, designed to reduce power usage, are commercially available

PUBLISHED : Wednesday, 22 August, 2012, 12:00am
UPDATED : Wednesday, 22 August, 2012, 2:22am


Related topics

Imagine appliances powered not by the electricity grid or even the sun or wind, but from used cooking oil. Or a bright, new, shiny kitchen with no trees harmed in the process of building it.

Welcome to the brave new world of eco-design. Such concepts are not the stuff of science fiction, or even futuristic. They already exist, should we choose to use them.

A visit to the low-carbon show flat at the newly opened zero-carbon building on Sheung Yuet Road, Kowloon Bay, reveals various green alternatives that challenge home life as we know it.

Architect Leung Man-kit, director of sustainable design at Ronald Lu & Partners, was project leader for the zero-carbon building - a first for Hong Kong and a showcase for cutting-edge eco-technologies globally.

Along with the 1,076 sq ft show flat, the site incorporates a functioning eco-office, an eco-garden and an urban native woodland.

Leung, who is working on a study about energy-efficient design of residential buildings for the government, notes there are wide variances between the environmental performances of buildings that affect their demand for energy. "There is a growing awareness and market demand for a greener, healthier, low-carbon living environment - this key driving force comes from the demand side," Leung says.

Every aspect of the zero-carbon building is designed to reduce energy consumption. The core components are the large and externally shaded openings (for cross ventilation and daylight); a cross-ventilated layout (facilitating good air flow); high performance glazing (which blocks out most of the sunlight); low external reflectance and high daylight transmission.

There's not an air conditioner in sight. Instead, air is moved by overhead fans on the three-metre-high ceilings. All appliances have a grade-one rating, the most energy-efficient in a five-grade rating system for energy efficiency, and are programmed to switch off or stand by remotely.

Low-energy finishes are used throughout: bamboo flooring, water-efficient taps, wood products from sustainable sources, and furniture made from timber reclaimed during local development works.

The zero-carbon building features countertops made from recycled glass, and show-flat kitchen cabinetry that looks new, but in fact was salvaged from landfill.

"You should have seen it when it arrived," says Christopher To, executive director of the Construction Industry Council, which developed the zero-carbon building. He was referring to the cabinets' poor, pre-makeover condition - evidence that even apparently useless items still have potential.

While most people do not bother to switch off the computer, printer and other accessories individually, the adaptor sockets found in the eco-home have a special energy management function.

For instance, when the computer is switched off, all installations plugged in with the adaptor sockets are switched off as well.

The zero-carbon show flat also uses all the "healthy" materials you would expect, such as low VOC (volatile organic compound) paints and adhesives, and it is powered completely by a combination of solar panels and used cooking oil, converted to bio-diesel at the onsite recycling plant.

Almost all the technologies showcased in the building are now available to homeowners, Leung says. They do cost more, but are fast evolving and getting cheaper as a result.

"Renewable technologies are relatively more costly, but many low-carbon architectural design principles and the use of green active and smart systems are realistic," Leung says. "The priority should be to control energy demand through good solar shading and natural ventilation as much as possible. This is effective and very affordable."

Leung notes that such installations might cost HK$10,000 to HK$15,000 for a typical 600 sq ft flat (saleable area), which can be recouped in two to three years.

Of course, this flat is a showcase, built from scratch, with all the environmental axioms at the architects' disposal.

Most Hongkongers don't have rooftops on which to place solar panels, or gardens for growing plants. And we're stuck with existing buildings, no matter which way they face.

But if Hong Kong-based American designer Ted Givens can arrest the forces of nature by designing a tornado-proof house in America - a structure pivoting on a series of hydraulic levers that would push the home in and out of the ground in response to external stimulation - then "greening" a Happy Valley high-rise building is surely not impossible?

Givens, a design partner at local architecture and design firm 10 Design, is a sustainable-architecture specialist. His research projects in collaboration with the University of Hong Kong and Tongji University in Shanghai are aimed at "greening" cities through the built environment.

He's also behind such initiatives as the Galaxy Yabao Hi-Tech Enterprises Headquarter Park in Shenzhen, whose eco-credentials include building facades that neutralise air pollution 24 hours a day (via a photocatalytic layer of titanium dioxide).

For his Hong Kong home, Givens could not do anything about his building's orientation and the ensuing ubiquitous lack of natural light, but he could change the internal dynamics to reduce its energy consumption. And he did it without a major renovation.

The first change was to paint every surface white to reduce the need for artificial lighting. "We kept the parquetry floor, sanded it and painted over with a matt finish," says Givens, adding that it "looks better than a bamboo floor", in reference to what is widely regarded as the most sustainable flooring material.

"When renovating, it's always better to reuse what you already have instead of introducing a new material, no matter how green," he says.

Some of the internal walls were removed to bounce light throughout the 800 sq ft apartment. Windows were upgraded with energy-efficient panes. The choice of laminated glass also made the windows child-safe, so Givens was able to do away with the iron bars normally fitted to high-rise flats, which allowed in even more light.

In what may seem counterintuitive in the city's air-conditioned culture, the Givens open their windows as often as possible. "We picked the unit because it faces the gap in the mountains behind Happy Valley and gets a constant breeze," he says.

"Orientation is the best way to reduce heat gain and promote natural ventilation. Our unit faces east/southeast, which greatly reduces the glare and heat gain of a western-facing facade.

"In a new flat you can have more alternatives such as introducing passive cooling, using stone floors, and exterior shading devices."

Leung says: "A cultural shift and green behaviour are no less important than any green design. In the zero-carbon building, we advocate behavioural changes such as cool summer business clothing, green operation and regular maintenance of building systems. Green buildings are only successful if they support green living."