Birds Island

Project type: Single Family House

 

Location: Kuala Lumpur, Malaysia

 

Time: 2007-2010

 

The design for zero-energy villas in Kuala Lumpur explores territories of design that have emerged in response to a new, rising awareness of sustainable design, translating energy-saving requirements into poetic design solutions that are not only environmentally friendly and efficient, but also offer a new interpretation of the spaces we live in. The design presents a cost-saving response to warm climate habitation.

 

The living quarters have an expansive shaded outdoor living deck, while the primary living space is located in the cooler interior core. The silicon glass skin envelope serves as a multifunctional translucent shell, casting subtle shadows and creating changing patterns of view, while freeing the space from the bonds of traditional walls. Curtains can be drawn to enclose living spaces, creating privacy.

 

This strategy is geared to cutting waste and eliminating redundant energy systems. The optimized building skin doubles as a frame with integral rainwater and solar heat collection systems, acting as wind flow conductor, and distributing rainwater. The entire structure is set on piers, minimizing erosion and affording natural cooling by allowing air to flow unobstructed under the floor. Solar lotuses in the water nearby act as satellite energy-collectors, providing the remainder of the energy needed for the structure to operate as a zero-energy building.

Design concept

The design concept for the zero-energy houses employs a holistic strategy that pairs the economic and environmental advantages of environmentally friendly living with the needs of a demanding, cosmopolitan clientele. Ecological and economical concerns should be perceived as augmenting rather than restricting modern lifestyles, improving living comfort while impacting less on the environment.

 

An expansive outdoor living deck spans the width of the site, while the primary living space is contained within the cooler interior. A dynamic tensile structure encloses the interior space, maximising the use and energy-efficiency of the space within. The thin building envelope creates a new relationship between indoors and outdoors, providing comfort within while freeing the space from the bonds of traditional walls.

 

The other living areas are arranged separately from each other, separated by channels of landscaped local vegetation. The fabric of the tensile skin flows over the interior, shaping and imbuing the spaces with subtle shadows and patterns, and providing glimpses of the outdoors. Heavy sliding curtains can be used to separate off private areas.

 

Understanding the term “zero-energy”

Every building needs energy for illumination, water heating, electronic appliances and cooking. In extreme climates – such as in the heat and humidity of Malaysia – energy is also needed for cooling. The term zero-energy refers to developments that use renewable energy sources on site, to supply the required energy. The architectural design goal is to minimize the energy requirement thereby reducing the amount of power that needs to be generated on site.

 

For Bird Island, the energy required for all six villas and for on-site electrical carts will be generated by an on-site solar plant and heat pumps. The solar plant and heat pumps will be centralized for the 6 villas and were not part of the design scope.

 

Skin

The skin is a tensile, environmentally-friendly fabric through which the outside world can be seen. The skin turns and twists along the façade varying in its degree of transparency and directing views out over the landscape and the surroundings. The parallel strips of fabric form patterns that appear to flow naturally over the skin.

 

For the climatic conditions in Kuala Lumpur we have proposed using a silicon-coated glass-fibre fabric instead of PVC-coated fabric for the skin as it is less susceptible to the high humidity and UV light in Malaysia, and is therefore more durable. In addition, it is easy to clean with a high pressure water cleaner and biodegradable detergent.

 

Material specification: Atex 5000, Heavy grade silicon-coated glass-fibre fabric. Weatherproof, hydrophobic, UV light resistant, no toxic emissions, no residual odours, easily cleaned, and dimensionally stable.

 

Materials

Wherever possible, renewable or recycled construction materials have been specified. Special attention has been paid to materials that either have low embodied energy, and/or superior durability and performance.

 

– Structural concrete with fly-ash instead of Portland cement: Recycled material
-Cellulose rigid insulation: Recyclced material
-Blockwork structural walls with fly-ash instead of Portland cement: Recycled material
-Water-pemeable concrete paving: Recycled material
-Recycled roofing made of recycled rubber tire granulate: Recycled material
-Hardwood timber cladding subframe: Renewable source
-Teak exterior decking from FSC approved plantations: Renewable source
-Bamboo tent structure: Renewable source
-Privacy curtains made of organic materials: Renewable source
-Hardwood Glu-Lam timber floor joists from FSC approved plantations: Renewable source
-Bamboo plywood from local sources: Low embodied energy
-Local natural stone cladding: Low embodied energy
-Local natural stone flooring: Low embodied energy
-Local natural stone wall finishes: Low embodied energy
-Aluminium window and door frames with thermal breaks: Performance
-Low-E argon filled double-glazing for optimal insulation: Performance
-Reflective vapour barrier: Performance
-Sliding tinted single-glazed doors in a timber frame: Performance
-Metal grid parking platform, minimum impact lightweight structure: Performance
-Mosquito netting: Performance

Part of the holistic building strategy is to optimise the use of building materials, thus reducing cut-offs and construction waste. We have also prioritised environmentally preferable materials and methods and minimised the use of solvent-based products, reducing environmental impact during fabrication as well as from off-gassing after construction. Many building elements are prefabricated e.g. the tensile fabric, timber platforms and Glu-Lam floor joists, and the natural stone cladding. These processes minimize waste and the environmental impact of the construction process.

This house has achieved a pre-certification total of 14 out of 14 possible total LEED homes credits for materials.

 

LEED

The home has been designed in line with the guidelines of the US Green Building Council’s Leadership in Energy and Environmental Design (LEED) certification system for environmental design. The LEED rating system was created to improve the sustainability of the built environment by providing consistent, credible standards for green buildings for the building industry. Depending on the number of credits a building receives in each of the eight categories of the design, specification and construction process, it is awarded a LEED rating of either Certified, Silver, Gold or Platinum. The design for the Birds Island home has achieved a pre-certification LEED Homes Rating of Platinum, with more than 90 credits. This is the highest possible rating, and provides credible proof of the environmental benefit and energy-efficiency of the design.

 

Indoor environmental quality

Measure to improve indoor air quality are important for environmental and energy conservation, as well as living quality. By employing methods to control humidity and moisture in the cooled building zones, we can ensure good comfort while reducing the risk of mould formation. The structure is ventilated with outside air as part of our integrated building strategy, thus minimizing the occupants’ exposure to indoor pollutants, humidity and adverse odours.

 

This house has achieved a pre-certification total of 11 out of 20 possible total LEED homes credits for Indoor environmental quality.

 

Appliances

Energy consumption, the conservation of water resources and light pollution are all major factors in the economic and living standard equation. All appliances have been certified as Energy Star qualified. ENERGY STAR is a joint programme by the US Environmental Protection Agency and the US Department of Energy with the goal of saving money and protecting the environment through energy-efficient products and practices. The refrigerators, dishwashers and washing machines, as well as the house lighting all conform to Energy Star qualifications for energy reduction and water and other resource waste. Additionally, the houses produce their own solar energy to offset their energy impact on the area. This house has achieved a pre-certification total of 28 out of 38 possible total LEED homes credits for Energy and Atmosphere.

 

Site stewardship

As part of our commitment to a holistic design and construction concept, extra care is given to the handling of the site during construction. These methods include:

 

– Erosion control during construction, preserving topsoil.
– Foundations: single piers with concrete footing, designed to minimize the building footprint.
– Minimum footprint: reduces top soil disturbance and avoids damaging existing plant roots.
– Prefabricated materials: e.g. tent fabric and timber decking reduces waste and dust production on site.
– Conservation of existing trees: reduces destruction of the habitat of local flora and fauna.
– Continuous landscape: site replanted with local flora native to Malaysia as shade.
– Non-toxic pest controls: use of lemon grass as a natural mosquito repellent.
– Continuous landscape: 90% of the original landscape is replanted.
– Access road: shaded permeable concrete paving prevents heat island effect.
– Continuous landscape: large reduction of storm water flow due to vegetation and permeable paving.
– High reflective roof materials reduce the heat island effect while reflecting 50% of solar energy back into space.
As has been stated by environmentally conscious designers, ‘White is the new Green’. This house has achieved a pre-certification total of 19 out of 21 possible total LEED homes credits for Site Stewardship.

 

Interior
– Vegetation intersects the living space
– The tensile fabric becomes a canvas for the play of light and shadow from the surrounding trees
– Mosquito netting in channel tracks surrounds the extended living space
– Heavy sliding curtains create privacy and improve acoustics
– Translucent tent fabric filters natural light and serves as a screen through which to view the outside world.
– ‘Windslider’ artificial wind provider
– Living room lounge
– Sliding glass doors around living spaces for security and weather protection
– Doors fold back to create a continuous indoor and outdoor living environment
– Thin films of water flow over stone surfaces for ambient cooling

 

Water cooling

Retreat living spaces:

The living spaces are the cool rooms within the house. The cooling system is simple yet effective: the rooms, shaded by the tent skin and naturally insulated to reduce heat gain, are cooled by harvesting cold rainwater in collectors in the ceiling during the day; and by using cross-ventilation at night. In extreme circumstances, additional cooling is possible using an air-conditioning unit powered by an environmentally-friendly heat pump. Rainwater can be released from the ceiling tank to cool the exterior cladding of the living space flowing over it in a gentle, beautiful waterfall.

 

Roof area: 428 m²

 

Min monthly rainfall: 9 mm / min potential water collection: 3.8 m³

Mean monthly rainfall: 238 mm / mean potential water collection: 101.8m³

Max monthly rainfall: 288 mm / max potential water collection: 123.2m³

 

– Provision of 378 litres of rainwater for a 4-person family per day as mains water substitute (based on UK average)
– Insulated rainwater tanks
– Rainwater is, on average, 10 degrees cooler than outside temperature
– Concrete ceiling cooling interior
– Air conditioning and de-humidifying unit powered by solar generator
– Rainwater tanks can be emptied as a thin film of water flowing over the building skin into the landscaped areas.
– The ‘curtains’ of flowing rainwater have a cooling effect on the surface they flow over and the air in the vicinity.

 

Ventilation

Extended living zone:

The extended living zone is shaded from direct sunlight by the tent and surrounding trees and cooled through natural ventilation. This natural ventilation is accentuated by the wind funnel shape of the living spaces and wind harvesting intakes formed by the tent skin. The living zones are positioned towards the centre of the direct wind path, allowing a natural airflow to circulate through the house, quickly dissipating any heat build-up inside the tent and maintaining a comfortable interior microclimate.

 

– Natural ventilation
– Site One is sheltered from the main wind direction by the forested island
– Chimney-effect tree canopy
– Sunlight heating the air inside the chimney creates a natural stack effect
– Laminar wind flow over chimney creates low pressure chimney effect
– Wind at low speed enters the chimney through forested area
– Funnelling effect of tent design enhances wind speed and wind chill effect

 

Water supply

Water consumption:

As responsible neighbours, each house attempts to minimise the amount of water it needs to source from the main water supply of the city. The design instead utilizes the abundant rain water resource of Kuala Lumpur as the main source of water. Potable water from the city main line water supply is used only for drinking water in the kitchen and bathroom sinks. All other water used is filtered rainwater (supplemented by mains water in dry periods). Exploiting the warmth of the sun, hot water is generated by solar boilers woven into the fabric of the tent which can heat both rainwater as well as mains water. LEED-certified water saving appliances are also utilized throughout the house.

 

– Average water use: 600 litres for a 4-person family per day (based on UK average)
– 63% (378 litres) of this is used for toilet flushing, shower, washing clothes and outdoor use and can be replaced by filtered rainwater
– Rainwater collection on the tent fabric
– Collection tank inside utility room roof
– Filtration and storage for hot and cold water in the utility room
– Solar boiler system integrated within the tent fabric provides hot water

 

Water drainage

Foul water drainage:

Reusable grey water from sinks and showers is treated and put through a filtration bed to help hydrate the foliage on site. Black water from the toilet is discharged via the main sewer to the local treatment plant.

 

– Grey water is collected and channelled to filter
– 18 m³ grey water filter with a capacity of 420 litres/day
– Filtered water is released within the building plot, ensuring all harvested rainwater is eventually replaced
– Black water drains to main sewer at a rate of 180 litres/day
– Annual reduction of 153 m³ of waste water to treatment plant

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