Infinity pool anyone...?

Marina Bay Sands is a world-class luxury hotel in Singapore capped by a boat-shaped 'SkyPark' perched atop the three towers that make up the world's most expensive hotel. 

If you fancy a dip in this pool, you'll need a head for the clouds. At a staggering 200 meters from ground level and at three times the length of an Olympic pool, it is the largest outdoor pool at that height. 

 While the water in the infinity pool seems to end in a sheer drop, it actually spills into a catchment area where it is pumped back into the main pool.The pool has two circulation systems. The first function is like that of a regular pool, filtering and heating the water in the main pool. The second filters the water in the catch basin and returns it to the upper pool.

 
 

Green fail

(Fig. 2.1Paradise Park Children's Centre)

Paradise Park Children's Centre

Paradise Park Children's Centre in London, at one time, had a lush vertical hydroponic garden covering certain portions of the structure. According to The Architects' Journal, the BBC, and the London Evening Standard, that time is no more.

The building was designed by DSDHA who wanted a living wall to mitigate against planting the structure on a portion of open park space.  DSDHA called upon landscape architect Marie Clarke and had the green wall system installed at a cost of £100,000.

According to the Architects' Journal, a spokesperson for Islington Council said, 'The wall was the first of its type to be installed in the UK and, as with anything new, carried a certain element of risk ... Of course, we're disappointed that it hasn't thrived. It seems this could be down to its design and we're looking at the best way to restore it.'

(Fig. 2.2 Paradise Park Children's Centre)

In response to this, Tim Newark, Islington Taxpayers' Alliance, said that the green wall was a costly waste of taxpayer money: “The architects should have worked out all the problems before it was installed ... The council should not experiment with taxpayers' money.”
 
The Cause of Failure

What exactly was the cause of the wall dying and failing ? Was it the design?  Construction?  Maintenance?  Or some combination of all three.

Whilst Islington Council maintains that the cause is still being examined and has found no evidence that the water pump of the expensive irrigation system was faulty, a member of the maintenance team disagreed with this.

He claims that the fancy watering system never worked.  It either under watered or over watered the plants.  So although some observers seem to want to blame the lack of maintenance for the wall's death, there's something more to the story.  Maybe it was designed to require too much maintenance...

According to other insiders, the water pump for the 9m-high wall broke and nothing was done to fix it. Mina Samangooei, who was studying Paradise Park for her MSc in sustainable building at the time, has no doubt this led to the wall's failure.

Marie Clarke of Clarke Associates, which built
the living wall on behalf of DSDHA, makes the strong claim that: “It didn't just die - the water
supply was turned off.”

Chris Churchman, partner at Churchman Landscape Architects, believes the disaster threatens the immediate prospects of living walls. “The failure of this particular scheme is going to raise doubts in people's minds about the viability of living walls as a valid technique for cladding,” he says.

(Fig. 2.3 Paradise Park Children's Centre)

“They are very much the product of the moment, the thing that everyone wants on their building, so everybody is moving into this market. But [clients] don't really understand them. “As a practice we took a positive decision two years ago to try to understand this technology, but if you go with someone who has only been in the business of designing living walls for six months, you're taking a big risk,”adds Churchman.

(Fig. 2.4 Paradise Park Children's Centre)

Co-director of the Oxford Institute for Sustainable Development, Fionn Stevenson, is also critical of the “science” behind the walls. “The incident in Islington proves how vulnerable living walls really are,” she says. “A so-called living wall relies on an artificial supply of water and fertilizer to survive, and the design.., is over-optimised and therefore very vulnerable. Unlike a natural eco-system it has no redundancy, so if one thing goes wrong, it all goes wrong. “Just keeping ‘a wall’ alive creates lorry-loads of embodied energy and pollution. The living wall cannot be sustainable because a basic principle of sustainability is that you do not live beyond your needs,' adds Stevenson.

Stevenson also believes that a living wall will not contribute to an eco-system if the designer has placed a threshold between the building and existing flora, as was the case at Paradise Park.

“Architects tend to treat them as a building element, but in fact they should think of them as a landscape element, to think how they engage with the ground and the roof of the buildings...Unfortunately, living walls have just become another part of the green eco-bling armory,” she adds.

(Fig. 2.3 Paradise Park Children's Centre)

A spokesperson for The Driver pub in King's Cross North London, which recently fitted a living wall, states that: “It is very risky - Patrick Blanc doesn't give you any guarantees.” French botanist and designer Blanc claims to have invented the living wall, and peddles his designs to clients such as international art galleries and hotels.

The Principal at Purcell Miller Tritton, Jeremy Blake, installed a nine-storey living wall by Blanc at the recently refurbished Athenaeum Hotel in London. “You're dealing with a living organism and that means it needs to be appropriately selected, appropriately installed and well maintained and irrigated.

(Fig. 2.3 Paradise Park Children's Centre)

“Your three key elements for a successful living wall are the growing medium, monitored
irrigation, and appropriate plant types for that kind of exposure.” A spokesperson for the
Athenaeum Hotel said: 'We have had a couple of bits which haven't survived, but the majority of it is looking quite lush.’

According to Blake, the Paradise Park incident 'will make people more aware of the critical issues that you need to ensure are incorporated
into the design of a living wall'.
That being said, it is still remarkably difficult to find any negative information regarding living walls.

Nicola Giuggioli - whose shop Eco Age in Chiswick, South London, designs and installs living walls - admits 'it is a learning process'.
Giuggioli encourages his clients, of whom are mostly residential homeowners, to buy a maintenance contract from him, whilst still warning them that there are still risks. 'During a cold snap we completely forgot to turn off the watering and the water froze - it broke the roots of the plants, which then froze and died.’

(Fig. 2.3 Paradise Park Children's Centre)

Doug McIntyre of Aldingbourne Nurseries, which installs living walls, claims that the incident at Paradise Park has had a 'knock-on effect' on his business. He says his clients are cautious, even though his walls, he claims, 'are superior' to those used at Paradise Park because they use a growing medium instead of rockwool.

The director at architecture practice FAT, Sean Griffiths, feels that living walls have become a substitute for having any ideas. The Belvedere, a tower designed by FAT proposed for East London, was to feature a 19-storey living wall by Blanc, which the client had requested, But Griffiths reckons that the tower is now unlikely to be built.

 (Fig. 2.3 Paradise Park Children's Centre)

Sources:

Fulcher, M 2009, 'Are living walls worth it?', Architects' Journal, 230, 9, pp. 8-9, Art Full Text (H.W. Wilson), EBSCOhost, viewed 12 November 2012.

Capital Regional District 2012, Canada, British Columbia, accessed 16 October 2012, <http://www.crd.bc.ca/index.htm>

Hainer Roofing System Co. Ltd. 2010,
People's Republic of China, Shanghai, accessed 04 October 2012, <http://www.hainer.cn/en/>

Jakob rope systems 2012, United States of America, Florida, Delray Beach, accessed 04 October 2012,
<http://www.jakob-usa.com>

Green Facades

 (Fig. 1.1 Green facade)

Living walls are also known as green-, bio-, vegetated-, living- or eco-walls and as vertical garden. At their simplest, they are vertical gardens and can include any type of vegetative covering of a standard wall, such as hanging gardens and climbing vines. 

There a few ways that plants can grow on vertical surfaces: the first is by affixing multiple rows of small planters to a vertical wall; the second is by affixing felt fabric to a wall, and sticking plants into pockets within that felt fabric. The second kind of living wall is more aesthetically appealing, and allows for plant varieties with more extensive root systems. 

(Fig. 1.2 living wall systems)

The third system is the use of planter boxes which can be planted on balcony edges and balustrading or on a ledge with access space. Trellis are then erected between the boxes on which the plants will grow and cover the whole facade of the building. This method will also act as a filter for direct sun light entering the buildings.

 (Fig. 1.3  Musee du Quai Branly in Paris)

In these latter systems, plants typically grow without soil between layers of fibrous material (such as felt or plastic mesh), or in pre-vegetated panels, that are suspended in front of a building wall. They are planted in the ground or in planter boxes. Based on the principles of hydroponics, water, with added nutrients, drips slowly to the bottom of the wall where any excess is pumped up and re-circulated. Some living walls incorporate a pool at the base of the structure which can include fish and small animals such as amphibians.

Structural weight, moisture retention, nutrient supply and water distribution are important design considerations in all living walls.

 (Fig. 1.4  Modular planted panels)

(Fig. 1.5  Concorcio building concept sketch)

Types of living walls

Green facades

These commonly feature vertical structural systems that support climbing plants on the building exterior. The vines and climber type plants are supported by stainless steel cables, mesh or metal grids and grow up from grade or planter boxes.

 (Fig. 1.6  Modular planted panels)

(Fig. 1.7  Modular planted panels)

Active walls

These are indoor features joined to the building’s air circulation system where fans draw air through the living wall before being circulated through the building to cool down and humidify the air, increase the oxygen levels and reduce pollutant levels.

 (Fig. 1.8  Potted systems) 

  

 (Fig. 1.9  Potted systems) 

Inactive walls

These types pf walls are also indoor features, but rely on passive open design for free air circulation rather than on mechanical air systems.

Outdoor Living Walls

Outdoor living walls are the engineered building envelope systems that allow a organic sun screen, a layer of living plant material to be suspended at some distance from the outside wall of a building (Fig. 1.9)

Specialized membranes and drainage layers support the growth of a range of mosses, vines and perennial plants. 

 (Fig. 1.10  Planter box)

Advantages

Depending on the system used, living walls provide shade for buildings, blocking the direct sunlight from entering, or in the case of the modular systems  they add thermal mass to a building. The vegetation will also lower air temperatures by evaporating enormous amounts of water from leaf surfaces, thereby moderating indoor and outdoor building temperatures.

Studies have found that the reduction of summer cooling loads by living walls are more dramatic than that for green roofs. The same study showed that significant reductions in the urban heat island effect could be attained if living wall technology was used extensively.

 (Fig. 1.11  Planter box)

Furthermore, the sound transmission into buildings are reduced due to the layer of plants, growing medium and, depending upon the design, the dead air space between the living and conventional walls. 

 (Fig. 1.12 Modular fibrous felt material)

  (Fig. 1.13 Modular planted panels)

Negative Aspects

Indoor projects will require monthly maintenance programs similar to other indoor garden requirements. For obvious reasons, the vegetated walls require an even higher level of maintenance than climbers on a vertical frame.

From a practical point of view, the sheer height of some outdoor living walls will likely pose challenges in terms of maintenance access.

Ii term of energy consumption, the more complicated engineered irrigation systems for the indoor living walls have been criticized for using too much electricity to supply light and pump water and nutrients through the system, and for using embodied energy in the building components.

However, it does not appear that a cost-benefit analysis has been done to clearly assess how effectively living walls achieve their various goals (including stormwater volume attenuation and cleansing) and at what price.

Proper air flow and water movement must be established to help ensure harmful moulds do not grow, particularly in indoor applications. In addition, the constant presence of moisture means that the walls must be well separated from the adjacent structure.

Designers should consider pollen generation when choosing plants, especially for indoor applications or beside operating windows.

(Fig. 1.14  irrigation system)

(Fig. 1.15  Module installation 3D)

 

 

And they all lived happily ever after...

 

THE END