The professional consensus states that any specific vertical covered in vegetation can be considered as a green facade. The most frequently used term in this field however is green wall. Recently, the meaning of the two terms are becoming increasingly separated in the professional literature: green facades refer to/became used for outdoor, whilst green wall for indoor plant walls/walls covered in vegetation. Quick hedges, fences covered with climbing plants, plant support walls and living-pictures are often referred to as “green wall-green facade”. The latter is not covered within the scope of the website, only structures belonging to the concept of “building construction” in a classical sense are examined and described here. Besides the term green walls, many synonyms are also in use for green facades, the most frequent ones are: plant wall, living-wall, vertical garden. Here the expression of green facade will be used.
The architectural use of green facades goes back a long way, at least the use of walls covered with climbing plants. Patrick Blanc, the French botanist, is considered by most to be the father of modern green facades, the actual inventor of the green wall system however is Stanley Hart White, who patented his invention in 1938, the improvement of the “botanic brick”: the building structure and system covered with vegetation. Our company designed and built the first green wall in Hungary in 2003 for the La Espada Argentinian grill restaurant. Although, sadly the restaurant no longer exists, we still continue our greening of vertical surfaces. The exact number of actual implementations in the world is not known, however, looking only at Patrick Blanc’s work, over 50 completed projects are associated with his name. In Hungary, to date, approximately 25 installations have been completed, with only five of them being outdoor structures. The world’s largest – 5324 m2 – built green wall is in Singapore. For further information, interesting facts and current issues click on the following link. moreless
Indoors vs outdoors
Many aspects of the two different spaces can be managed on similar principals, however, there are numerous and significant differences. Whilst indoors, the greatest challenge is providing sufficient light, outdoors the hardest task is managing the environmental and climatic effects (especially extremes in temperature). Whilst the indoor climate is more or less consistent (human comfort zone) anywhere in the world, outside we meet extremely variable and seasonal changing (macro, mezo and micro) climatic conditions, which means that no two tasks are ever the same. In line with this, the installation of an indoor green facade is a relatively simple task, given sufficient professional expertise, and with mature globally applicable and not over expensive technologies readily available. For more details on the questions and available solutions regarding the installation of indoor green walls click here. Externally, understanding of a much greater magnitude of complexity is required in order to create green facades that in the end function and provide long-term decoration in accordance with the expectations of the client. Our website focuses on outdoor green facades. moreless
We aim to provide professional support primarily for the architectural and landscaping profession who are most familiar with the topic, in the hope that we may contribute to the development of this architectural-landscape tool through increasingly high quality projects. moreless
When there is a soil connection
If the facade structure to be covered by plants has connection with the soil, a climbing plant system can be used. These are relatively cost-saving and simple solutions; however, there are several compromises that need to be made, among others in the selection of plants. The major advantage of these solutions is their inexpensiveness as well as their traditional acceptance. For the appropriate development of the plants, a sufficient quantity of soil that is appropriate to the needs of the plant is required. In many cases, on building sites, this is not available, therefore, the provision of additional artificial soil needs to be ensured. moreless
Climbing without a support structure
All green facade systems have their natural configuration. Plants holding onto trees in the jungle or climbing onto cliffs (epiphytons) can be considered as configurations for plants climbing onto the facade of buildings. The potential climbing height of the trained plants is genetically restricted to a scale (2-20 meters) dependent on the species They require minimal maintenance, however, there is a risk of damage to the facade by the roots or the large foliage mass. The number of plants that can be trained this way is rather limited.One of the most attractive examples in Hungary is on the wall of the headquarters of the Chambers of Hungarian Architects, the Almássy Palace. moreless
Climbing with a support system
The training of the plants available in this group requires a support system, which the clinging parts of the plants (tendril, offshoots) can cling to. When designing the framework, engineering considerations are an important factor. The foliage weight of mature plants is difficult to determine in advance as it depends on a number of factors, thus these structures are characteristically significantly oversized. The support structure is typically a trellis, mesh or simple wire; the material is mostly stainless steel or wood. A support system is required if the plants are not able to cling to the wall on their own or the wall is not suitable to receive them. In addition to the static design of the system, the architectural appearance is also important as the majority of usable plants are deciduous, therefore in winter and until full coverage, the support structure itself needs to be aesthetically pleasing. The installation of a high standard stainless steel support system requires thorough technological knowledge and careful planning. The price range of these systems is considerably higher than the previous type, although in return, the range of available plants is much wider. The support system contributes to 98% of the increase in price; any cost increase associated with the plants is minimal. The temporal and spatial growth limits the plants, similarly to the installations without support systems, and has to be kept in mind. moreless
No soil connection
The majority of systems that do not require soil are based on the principles of hydroculture, where, in contrast to traditional “soil culture” plants, a substantially smaller rootstock is sufficient for plant growth. It is of primary importance to keep both the price and the weight down. The plants to be installed are pre-grown in a soil culture, the majority of which maybe removed on planting. The traditional loam or peat based substrates raise many problems in addition to their large weight; they become compacted, their structure and through this their water and air management is continuously degrading, eventually becoming completely unsuitable for growing plants. The question arises then arises as to why in traditional plant production soil culture is (almost) ubiquitously used, possible factors include the following:
1. In traditional circumstances, we can typically use large volumes, while in the case of green facade-green walls the size of the root stock is strongly restricted for both financial and technical reasons. This requires the use of a more “efficient” growing medium.
2. The satisfactory condition of traditional soil can be reconstructed year-on-year by agrotechnical methods (inverting the soil, manuring etc.). In the case of green facades, this is technically and practically virtually impossible.
3. The price of soil medium or loam and even of peat is considerably lower than effective hydroculture mediums and generally can be sourced locally.
Hydroculture systems at first glance may appear rather synthetic, however these also have their natural synonyms, and the perhaps most authentic prefigurations of vertical green surfaces is where plants develop from the cracks and crevices of cliffs. This in essence is hydro culture itself, as in this case, the substrate is also inorganic fragments (aside from the often very limited rooting area). The modern green facade systems in point of fact copy and develop (to varying degrees and methods) this model to higher and higher degree. moreless
Credited to Patrick Blanc, this is the earliest versCredited to Patrick Blanc, this is the earliest version of systems not requiring soil connection. The system is built by fixing a watertight material (to protect the frame and wall) to a frame that is secured to the façade. One or more felt or textile layers are added with the plants inserted being between layers, into the pockets cut onto the outmost felt layer, and root over time into the material. With this system, although not too costly, technically there is much room for improvement:
1. Then surface of the felt material is not specifically aesthetic, even when new, and after a short time due to mineralisation and algae it may not be viewed as at all attractive. This does not represent a problem as long as the foliage coverage is 100%, however in case of loss of foliage due to any reasons (which is unavoidable in our climate), this surface will show.
2. The material easily tears or is damaged, the changing and replacement of plants (this is also unavoidable) mechanically damages the felt, which can become unsuitable for the task.
3. As the structure is so thin, the damping effect of the system is minimal, thus the root stock serving as the “engine” of the plants is highly exposed; it has to react without any buffer to the environmental changes (winter-summer) and maybe damaged even in milder extremes of weather.
4. Although we can consider the widespread growth of the roots, within the monolithic structure, as an advantage of the system in many applications (monoculture, figurative landscapes, logos, etc.) this is exactly its greatest disadvantage. In mixed plantings where keeping the original planting order of the vegetation and the required visual appearance is markedly close to nature, in theory it does not represent a problem that in the fight for the limited rooting zone some plants overcome others. In this way, the appearance of the surface develops spontaneously, and with time the more aggressive species take over. The variability of the landscape can only be maintained by replacements, which is not tolerated well by the felt medium in the long run.
Having said this, to date, the best known installations (Caixa Forum – Madrid, Musée du Quai Branly – Paris, Athenaeum Hotel - London) were built with such systems; less well known is that the decorative condition of these surfaces can only be maintained by regular significant plant replacements and rather high costs. Besides the premium locations and the indeed beautiful installations referred to, the large number of poorly done, often rather subdued landscapes are typical; this early technology is now being superseded. moreless
This system is closest to the balcony box planters. In a container green wall system the planters are placed in multiple lines above the each other. The pots may be made of metal, wood, plastic in a wide variety of sizes and designs. It has to be water and weatherproof, thus in respect of the usable material the same questions arise as in the case of modular systems, which are of similar price. The use of hydroculture is also recommended for this technology, and although soil based mediums can be used, all of the previously mentioned disadvantages have to be considered. The best example of this technology is on the Bercsényi street façade of the Allee Shopping Centre in Budapest. moreless
The modular solutions combine the benefits of the pocket and container systems, while trying to eliminate their disadvantages. The material is typically plastic or metal, and the plant growing system is almost exclusively hydroculture. Compared with the previous systems, they provide further technical solutions. The developments in recent years focused mostly on lowering the cost price whilst retaining these beneficial qualities. Today’s research targets almost entirely the creation and perfecting of such systems; the modular systems dominance is continually increasing amongst completed installations. The appearance required after installation can be precisely planned and even 100% coverage can be provided immediately following implementation. Systems of various designs and prices are now available in the market. The green façade system greenwall.pro is also in this group; its final structure emerging by the summer of 2014 after detailed comparative analysis of the market’s leading products, and based on a five year developmental stage with a three year testing period of the final prototype. moreless