Green Shoots

29 July 2009 (Last Updated July 29th, 2009 18:30)

Stringent energy-saving guidelines are driving building design concepts that reduce carbon emissions. Jodie McLeod looks at three projects leading the way in sustainable architecture.

Green Shoots

Ann Demeulemeester shop, Seoul, South Korea

This Seoul fashion store for Belgian clothing designer Ann Demeulemeester wears its heart on its sleeve. South Korean architects Mass Studies sought to integrate nature as much as possible within the constraints of a low-elevation, high-density urban environment and a limited site area (378m²). In doing so, project architects Minsuk Cho and Kisu Park dressed the shop's south-facing façade head to toe in a herbaceous, perennial known for its dense and glossy coverage, as well as
lining one interior below-ground wall with moss.

The living walls act as a natural cladding system, providing solar protection during summer and thermal insulation in winter. The moss wall emphasises the building's connection with the outdoors; the green walls and the organic architectural forms represent the amalgam of nature and the manmade. "This building is not meant to be just another object to be experienced externally, but a synthetic organism of nature and artifice," say the architects.

The building comprises one below and three above-ground floors, with the shop located on the first floor, a restaurant above and a multishop in the basement. It is situated in the once residential district of Gangnam, which is being transformed into an upscale commercial district.

"The living walls act as a natural cladding system, providing solar protection during summer and thermal insulation in winter."

The structure's greenness and natural contours are symbolic of these opposites working together to build a better future. An exposed stairwell entrance on the eastern side of the building represents this spatially, putting the basement level and the upper floor restaurant in direct contact with the outdoors. A hidden terrace at the back of the building and an al fresco rooftop dining space maintain the interior-exterior connection.

Along the north, east and west sides of the building, façades clad in steel sheets and finished with propylene resin face onto dense bamboo walls that border neighbouring sites. The living façades are structured as a grid to accommodate the plants. Despite some shrinking in winter, the plants remain healthy year-round thanks to a custom-made exterior watering system.

Each unit is hydrated by a hose that runs along the horizontal panels. The hoses are connected to a control system that monitors the amount of output, depending on climate. For the moss walls in the basement, a machine creates mist that deepens the strength of the green odour, creating a cave-like atmosphere.

California Academy of Sciences, San Francisco, USA

The Academy's new building in Golden Gate Park is a model of sustainable design. The £320m structure achieved the Leadership in Energy and Environmental Design (LEED) platinum rating from the US Green Building Council. Maximising its use of natural resources and employing the very latest in energy-efficient technologies, the Academy will use 30% less energy than federal and state requirements.

Designed by Italian architects Renzo Piano Building Workshop, the 37,000m² building houses an aquarium, a 27m-diameter planetarium dome, a natural history museum, a four-storey rainforest and research facilities. The most striking feature is the building's 2.5-acre undulating living roof, carpeted with 1.7 million native Californian plants. Designed by US environmental design company Rana Creek, the green roof carries many energy-saving advantages. Padded with 6in of soil it keeps the interior temperature 10°C cooler than standard roofs, uses reclaimed water, and addresses storm water management issues by preventing 3.5 million gallons of rainwater from entering San Francisco's storm water drains. The contours of the ceiling encourage hot air upwards providing natural ventilation while, at the centre, a curved 72ft by 98ft glass skylight provides natural daylight.

"The Academy's new building in Golden Gate Park is a model of sustainable design."

The heating and cooling strategy designed by engineers from Arup is based on natural ventilation, with supplemental heating and cooling provided by a hydronically heated and cooled floor slab.

The ventilation system is controlled by a central automation system, which measures slab and air temperature, CO2 levels and relative humidity. In the offices, the system provides manual control for staff to ensure comfort levels.

Sunlight is minimised by the 30ft roof overhang and by motorised sunshades protecting some of the glass walls and canopies. "This prevents the majority of the sun's heat energy from entering the building, and allows the natural ventilation and passive cooling strategies to work," says Arup Associate Karl Lyndon, one of the mechanical engineers on the project.

Use of reclaimed water and low-flow fixtures allow the building to use 20% less water than required by code, and reduce reliance on municipal potable water for wastewater conveyance by 85%. The structure features a perimeter steel canopy supporting 60,000 photovoltaic cells, providing 220KW of energy annually. These will supply 5% of the building's total energy.

ETH Zurich e-Science Lab, Switzerland

Austrian architecture firm BaumSchlager-Eberle is behind the highly energy-efficient e-Science Lab at ETH Zurich, the science and technology-focused university in Switzerland. The £37.5m 'no-frills rectangular block' has a floor area of 11,655m² and an energy demand of 93kWH/m², less than half the average demand of university buildings in Germany and Austria.

While the interior is a breeding ground for technological innovation, the architects wanted to create a non-technical structure that would rely on its own form and smarter use of natural resources to achieve energy-saving goals.

The outer shell of the building, made up of rows of travertine blinds, is the science lab's definitive green feature. These shading devices sit out from the glass walls of the inner shell, separated by balconies, which differ in dimensions according to their orientation toward the sun. "The balconies and travertine blinds are designed so that there will be no solar radiation from April to September at the glass-front," says project director Marco Franzmann. "This will minimise external heat loads – a main problem in [achieving] the energy balance nowadays."

"The e-Science Lab makes use of photovoltaics and daylight dimmers."

The building had to allow for a flexible internal programme so its main internal elements comprise a central hall and multimedia teaching facility called the Value Lab, as well as six seminar rooms, the walls of which shape the space of the auditorium.

The building also has the potential to house 500 individual workspaces.

Taking into account these layout possibilities, the heating and cooling strategy accommodates for open or cellular offices. The architects have used Kilmavent floor-mounted induction units (FMIUs) developed by German air technology engineers LTG Aktiengesellschaft, which enable each workspace to experience its own microclimate. Each FMIU brings fresh, cool or warm air into the space, controlled by the user using a wireless solar control unit. The combined air and water systems save energy by controlling the airflow to maximise thermal comfort, and minimising waste heat with a recovery system. The building also has a fresh air inlet via a cooling soil duct, in which concrete pipes underground breathe external air into the building, passing it first through the naturally cooling channels of earth-covered pipes. The e-Science Lab makes use of photovoltaics and daylight dimmers, which culminate in a Minergie-Eco-certified building.