natural ressources and conscience

Un jardin sur les toits is a  consulting agency  and creative studio providing original content and innovative concepts in botanical and environmental subjects, combining scientific research and  wellness improvement.
Our vocation is threefold - design combined with sustainable development and ecological initiatives.
We practice the language of plants to give a tangible form to our desire to rethink the use of urban rooftops or all kinds of dedicated spaces in or out the cities.
We have set ourselves the challenge to improve air quality through a series of innovative proposals related to botany and technical innovations.
Placing medicinal plant or algae in the urban environment has emerged from our desire to restore the major role of Nature upon environment and wellness.
Our priority is to study the mechanism of botany in a polluted environment and to provide tangible solutions to improve health by improving air quality.
The benefits of using plants and algae have now been established and surely confirmed: massive absorption of CO2 and fine particules, combined with the reconstitution of the ecological network.
Given our aim to pursue the experience further, we consider it is essential to create a research station to analyse the development of plants in the urban environment on-site.
Driven by the desire to create a genuine synergy between the different participants in the field, exchanges between researchers are programmed and educational tools developed.
This dream, which takes shape day after day, is born from the "un jardin sur les toits" group's passion for plants and more generally for botany.


The air bubble
Located near the future station of the Grand Paris Express Nanterre La Boule (line 15 West) and carried by OGIC, the project Bubble Air aims to constitute a new entrance to the historic center of Nanterre in support of a building on the Place de la Boule, with a waterfall plant.
Designed by Brenac & Gonzales and Caractère spécial / Mathieu Poitevin Architects, Un Jardin Sur Les Toits is in charge of developing well-being for users, as well as the development of a Micro Algae Farm, a garden of Medicinal plants, an Aromatherapy program and, more generally, all botanical innovations.




The primordial atmosphere
Today, our atmosphere is composed of about 21% of oxygen, 78% of nitrogen, and 1% of small quantities of various gases: argon, neon, hydrogen, etc. But it has not always been so! It is estimated that Earth's primordial atmosphere - about 4.5 billion years ago - was mostly composed of hydrogen, nitrogen, carbon dioxide (CO2), ammonia (NH3) and methane (CH4). No oxygen, therefore! Or in very small quantities, of the order of only 0.0001%.
Therefore, we are talking about the absence of O2 gas , at that time.  Paradoxically, the oxygen atoms were  all there, and they were  even among  the most abundant elements on earth. But for the most part they were linked to carbon to form CO2 or trapped in rocks of the crust and mantle.

All this changed with the appearance of life about 3.5 billion years ago. A key element of life as we know it, is the ability to produce organic carbon molecules (such as carbohydrates, proteins or lipids), which serve as sources of energy. To make them, living organisms have to find carbon. The first bacteria found their carbon by picking up what came within their reach as nutrients (humans do the same). But about 2.7 billion years ago, a new type of bacteria appeared: cyanobacteria.

Cyanobacteria were the first to invent photosynthesis as we know it. From CO2, water and solar energy, these bacteria - sometimes also called blue-green algae - were able to capture the carbon in the CO2, while rejecting oxygen! Unlike plants (which convert mineral nitrogen into organic nitrogen) and animals (which convert organic nitrogen into another organic nitrogen), cyanobacteria (and a few others) are able to take nitrogen directly into the air, gaseous form, and turn it into organic nitrogen. They thus put 100 million tons of mineral nitrogen a year at the disposal of plants on the planet.
Cyanobacteria, which make up a good part of phytoplankton, contribute significantly to the surface fixation of oceans, atmospheric carbon dioxide (CO2). This role is of major importance today because of the increased production of this greenhouse gas by human activities.
As an essential link in oceanic food chain, they contribute greatly to the transformation of CO2 into carbon (the organic pump) and its storage in deep ocean sediments (carbon sinks), in reserve for the future needs of the planet.

Air Composition
Dioxygen, O2: 20.9476%
Nitrogen, N2: 78.084%
Argon, Ar: 0.934%
Carbon dioxide, CO2: 0.0314%
Hydrogen, H2: 0.000 05%
Neon, Ne: 0.001 818%
Helium, He: 0.000 524%
Krypton, Kr: 0, 000 114%
Xenon, Xe: 0.000 008 7%

The measurement of oxygen content in inhaled air is fundamental to health, (as well as we measure the various primary pollutants: oxides of carbon, sulfur, nitrogen, VOCs, PM10 and PM2.5 particles , metals or light hydrocarbons and ozone), the constant must be 21%.


The combined action of land and oceans on atmospheric oxygen
Photosynthesis, respiration and dissolution in seawater act simultaneously and vary the concentration of oxygen in the atmosphere. These variations were measured by Keeling and Shertz (1992) in three places on the planet: Alaska, California and Tasmania. In the first two, both located in the northern hemisphere, there is a maximum of atmospheric oxygen in summer and a minimum in winter. The summer maximum is mainly due to the photosynthesis on the land surface that characterize this hemisphere. In winter, breathing and dissolving in the colder sea water combine to give rise to a minimum. Between maximum and minimum, the difference is approximately 26 ppm (parts per million) in Alaska, and 20 ppm in California. This difference is smaller in Tasmania (18 ppm), the southern hemisphere being mainly occupied by the oceans and terrestrial photosynthesis only plays a small role. These seasonal variations are very small compared to the oxygen concentration of about 200,000 ppm. The highest, that observed in Alaska, represents only 0.013%. Even a small change in the oceans balance , or global photosynthesis (even in the case of the Amazon, the so-called "lung of the planet"), could threaten the quality of the atmosphere in the medium term.

Human disturbance

For more than a century, man has been meeting his energy needs by burning coal and hydrocarbons from photosynthesis of past geological eras. This combustion consumes oxygen. Similarly, the increase in the world's population has led to the clearing of forests and replacing them with crops. This practice also results in oxygen consumption. On one hand, the biomass that constitutes the forest, very high, is largely transformed into carbon dioxide. On the other hand, agricultural practices generate an impoverishment of the soil by degradation of the organic material they contain (humus). This degradation is caused by organisms that breathe and therefore consume oxygen. The corresponding decreases are in total at the rate of about 4 ppm / year or about 0.002% of the oxygen content of the atmosphere.
Again, there are reasons to fear a lack in the decades to come, as the emissions of carbon dioxide by the man continue to increase every year .

Oxygen tends to associate with other chemicals to oxidize (burn). Thus, stocks of carbon or organic matter that do not currently participate in the living matter cycle could "go up in smoke" by incorporating oxygen. Soil organic matter is an example as we saw above when forests are cultivated. Oxidizable carbon stocks are available in the Geneva based 5th IPCC ( Intergovernmental Panel on Climate Change )report. Knowing that an oxidized carbon atom in a carbon dioxide molecule consumes an oxygen molecule, a rapid calculation gives, in case of rapid global oxidation of these stocks, the following orders of magnitude (percentages of decrease in atmospheric oxygen):
oxidation of hydrocarbons (gas) - 0,19% oxidation of hydrocarbons (petroleum) - 0,07% oxidation of coal - 0,16% oxidation of organic matter of soils - 0,64% oxidation of permafrost - 0,55%
Oil, gas and hydrocarbons, if they pose a threat to the climate, can therefore cause, in the case of intensive mining, a decrease in the oxygen concentration of the atmosphere.

According to a study of the INRS "National institute of research and security" on Confined Spaces, the measurement in oxygen content in a confined or polluted space must be controlled: Measure Oxygen Content Together, the oxygen content of the ambient atmosphere will be monitored using a portable oxygen meter. If the oxygen content is less than 19%, penetration should only be carried out with respiratory protective equipment. It should be noted that any measured oxygen concentration below 20.5% already reflects
an anomaly in the atmosphere of the confined space (oxygen consumption or accumulation of another gas).
Its role of atmosphere purifier.
Spirulina is a great provider of oxygen. Forests play an important role in storing carbon dioxide (CO2). Trees are the best plants for fixing carbon: from 1 to 4 tons per year and per hectare. But Spirulina is even more effective: in the California desert, it can fix up to 6.3 tonnes of carbon per hectare / year; at the same time it will produce 16.8 tons of oxygen (ha / year).
Spirulina is the only fixed nitrogen .....
Purification system: François Haldermann presented at the symposium of Mialet on spirulina (in June 2012), his aeration system made in Ecuador to digest organic matter accumulated in culture media. We go from a BOD (biological oxygen demand) of 15mg to a BOD of 8mg. This aeration system allows a total recycling of the culture medium, while maintaining high productivity basins.

Microalgae and heavy metals

Microalgae culture in a continuous photobioreactor
These studies confirm the fixation of dissolved CO2 in the form of organic matter via photosynthesis. The different carbon species, which are formed during the dissolution of CO2 in the aquatic environment, and the formation of O2 depend on the temperature and pH.
It is clear that the nitrogen concentration acts directly on the formation of biomass thus defining the amount of protein and chlorophyll per cell. Phosphorus fixed by algae is also necessary for the transport of photons during photosynthesis.
Carbon metabolism and the assimilation of nitrogen and phosphorus are therefore directly influenced by enzymatic regulations associated with heavy metals.
Since carbonic anhydrase is a zinc-containing metalloenzyme, a decrease in its activity in response to zinc deficiency may affect the entire
carbon metabolism of the cell and therefore the production of intracellular metabolites. often the functioning of the photosynthetic apparatus, for example a too low concentration of sulphide will reduce the flow of electrons at the level of the photosynthetic apparatus (Rochaix, 2001) and a decrease in the iron concentration will induce a decrease in the constituents of the photosynthetic apparatus (PSI, PSII, cytochromes) because they have many co-factors containing iron (Terauchi et al., 2010). Similarly, since copper is present in many enzymes in the photosynthetic apparatus, its limitation impacts photosynthetic metabolism (Hill et al., 1996, Rochaix, 2001). But other intracellular processes may be involved; this is the case of nitrogen metabolism, the assimilation of which in the cell is reduced during a molybdenum deficiency in the medium (Glass et al., 2009). An increase of these elements in the medium will, conversely, have a positive impact on the cells. This is the case of magnesium or iron which allow the increase of the cellular concentration when they are in higher concentration in the medium (Mandalam).

In conclusion we are able to say that the Cyanobacteria "Spirulina" feed on CO2 but also fix nitrogen and heavy metals such as lead, arsenic and cadmium while restoring O2 (dioxygen) in large quantity. Spirulina is therefore a most effective air purifier.
Although it is mostly used today for its biomass and the production of clean energy, several companies and research centers such as NASA, ESA or Suez, already use it for its depolluting properties.

 Un Jardin sur les toits, presents the first Organic Oxygen Farm based on micro-algae production by biochemical conversion of CO2 to O2 in photobioreactors.
- Plan area 10 000m2 (up to 500 000m2) + Laboratory infrastructure/facility
The plant develops up to 2.6 meters height. In this configuration it is composed of 22 modules. The process is based on the absorption of CO2 by selected algal strains prepared on a laboratory scale and subsequently inoculated into the growth volume in the plant on an industrial scale.
Downstream phase relating to the extraction of Molecules with high added value and Oxygen by means of a patented generator.



Un Jardin Sur Les Toits and the CCCC CENTRE DEL CARME CULTURA CONTEMPORANIA and the CONSORCI DE MUSEUS DE LA COMUNITAT VALENCIANA present an immersive exhibition “the secret life of micro-algae“ at the CCCC of Valencia - Spain 2023/2024

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Complete redevelopment of an 1930 art-deco building roof-top garden with a pollution analysis laboratory.

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 29,CHATEAUDUN MICROALGAE greenhouseS    image
Creation of a roof top garden laboratory and micro algae greenhouses
urban solutions  image
Technology and science, combined with natural resources, offer today multiple solutions to improve urban environment. Many possibilities exist to reduce pollution of air and water, to eliminate noises, odors and electromagnetic nuisances, to insure healthier food, and to offer healthy and relaxing environments (homes, hotels, offices and gyms) for living, working, and fitness activities. Our commitment is to help our customers to find the best solutions to their requirements, combining new technologies and natural sciences, and to establish new standards for a high quality of living and wellbeing.
Catalytic filters, UV treatment, Ionization and photo-catalysis are only some of the technologies which can be used to improve air quality and eliminate atmospheric pollutants, fine dust and particulates, chemicals and COVs. While technology can help to eliminate pollutants, we suggest plants and photosynthesis to provide in addition an enriched air, to re-equilibrate the amount of ideal oxygen concentration. Plants like the Epipremnum aureum or Dracena Deremensis help to eliminate Formaldeyde; Guzmania lingulata eliminates COVs; Sanseveria eliminates CO2 and produces O2 during night. BioWalls and Spirulina cultures are efficient solutions for air quality improvement.
Technologies greatly help also for water treatment. The latest generation pools and spas, instead of using aggressive chlorine, use natural salt electrolysis to purify water and to disinfect from bacteria and fungi. They also employ ultraviolet light to dechlorinate water so that the disinfected water is not irritant for skin and mucosa and not aggressive for bath suits. Used in shower heads, red tourmaline ceramics invigorate the bath with a Spa effect, projecting far infrared waves; germanium black ceramics produces negative ions and has a cleaning action on the skin by neutralizing dirt, grease and odors, and greatly reduces the use of soap and shampoo; antibacterial white ceramics prevent the formation of pathogens in stagnant water in the shower. Hydrogenated water, according to several studies, works as an antioxidant, neutralizing free radicals and fighting against degenerative processes, skin ageing, wrinkles and other types of oxidative stresses. Water rich in molecular hydrogen, obtained by electrolysis, is used since more than ten years in Japan for multiple purposes like diabetes reduction, elimination of lactic acid for sportsmen and as antiaging.
 New composite materials with air traps and 3D structures are used to decrease noises; smart textiles insulate from electromagnetic fields; catalytic fabrics and nanotechnologies are used to eliminate odours, while aromas and essential oils diffusers are used to create stimulating and fortifying, or relaxing and soothing environments; essential oils  also offer antibacterial properties which are already greatly used in hospitals, nurseries, veterinary clinics and pet shops.
Availability of healthy and quality food with zero impact on environment is one of our nowadays priorities. Local cultures and local food transformation automatically bring to transports reduction, less environment pollution, a simplified logistic, availability of fresher food in urban environments. Urban spaces for cultures are smallest in size but not for this less productive.
One of our specializations is to study the settlement of aromatic plants, medicinal plants and vegetable crops cultures in urban environments (city gardens, roof tops gardens, vertical gardens, underground gardens).
Hydroponics and aquaponics are soil-free methods which can be used to cultivate crops with high nutrients levels. Aquaponics combines hydroponics (soil-free crops cultivation) and aquaculture (fish culture) in a controlled environment, to create a balanced ecosystem that benefits the crops as well as the fish growth. As the fish grow, the tank becomes filled with excreta and other waste matter. Water needs to be changed frequently so that the fish can survive and flourish in clean water. The waste water from the fish tank, treated with natural bacteria, becomes a precious natural and valuable nutrient for plants.
Pea, radish, coriander, arugula, mushrooms are only examples of what could be cultivated in underground farms built in unutilized underground tunnels or bunkers. A constant temperature of 15-16°C is ideal for cultures insuring no parasites growth; a LED system can be used to light the plants. Underground farms can produce all year long fresh and tasty vegetables for local restaurants and supermarkets without pollute the environment and without occupying urban spaces.
 Creative solutions are possible!
The ancient Greeks expressed balance by the phrase "Mens sana in corpore sano" (Juvenal 90 after JC)
The well-being of the body obviously passes through 3 great axes:

- 1) The environment
- 2) The health of the body
- 3) Peace of mind
1) In order to evolve in the healthiest possible context, our exclusive protocols offer
effective solutions to reduce pollutions as: air, water, olfactory, sound and light.
With the proven benefits of scientific Aromatherapy we have elaborated multiples synergenic protocols to fight harmful bacterias, dangerous for our health and wellbeing.
2) The health of the body is a delicate balance between nutrition and excercise
We recommend, a healthy food, produced nearby in hydroponics or aquaponics Urban greenhouses.
Coupled with martial arts that incorporate a spiritual and moral dimension aimed at self-control.
Martial arts have multiple forms and can adapt to all ages and all levels. They are ideal for the overall development of each individual.
3) Peace of mind
Therapeutic gardens as Medicinal gardens or Zen gardens contribute by their beauty to the peace of mind.
They are favorable to meditation.
The practice of an art or a craft, are  paths  worth exploring in order to find peace and balance.


The project to install medicinal plant garden or algae farms will not be complete without the support of a research center. The aim is to analyse, in situ, the interaction and development of vegetation in a polluted environment.
The role of vegetation in sustainable development, as well as the impact and interaction with the climate, temperatures, energy, hydrology at different levels will also be studied.
This research center will exchange with international researchers and university staffs specialized in botany, meteorology and entomology. Experts will also be invited to visit the urban physic garden and farm to study the impacts on site.

Possibilities for lodging such visitors are being considered.

The study of the impact of vegetation on climate temperatures and hydrology is a new discipline.
This multi-disciplinary activity seeks to provide key notions about the role of vegetation and to give contextual results.

It is difficult to generalise results given the variability of various determining factors which are more or less wellknown.

The term "vegetation", for example, covers a wide diversity of species with different physical and physiological properties: resistance to drought and evapotranspiration, colour and albedo, density and leaf persistence, etc. Local meteorological conditions (sun, wind,and hydrology) vary significantly in the urban environment. Management also plays a major role which is complex to standardise and evaluate.

The impact of vegetation in a polluted environment is no longer questioned, but adaptability remains a question which requires a great deal of research.

Ecosystemic services are fundamental to the urban environment.Major  cities must confront demanding environmental objectives which  may sometimes   seem contradictory, such as densification to limit urban spread, biodiversity maintenance, anticipating and limiting climate change, the reduction of greenhouse gases and providing a healthy and agreeable environment for the inhabitants. These issues must be taken into account at every level of urban spatial intervention and be monitored over time. Practically speaking, this requires constant interrogation about the relative roles of urban and vegetation forms. Unlike a botanical garden, our aim is not to register a maximum number of plant specimens in an encyclopedic manner. Rather, the aim is to carefully choose endemic plants or introduce exotic plants which have a great capacity for adaptation and can interact directly with our urban environment. We will specifically target medicinal plants, creating the possibility to reintroduce them and study them in an urban context. 

THE LAB  image


The choice of a physic garden was evident, given the training received by one of the collective member, who has a diploma in phytotherapy.

Through the development of a physic garden, we can also contribute to the discovery and rediscovery of medicinal plants, highlighting the didactic and educational aspects of officinal plants and the wonders that nature provide us.  Also a digital herbarium could be made available to the general public.

Integrated in an urban zone, a physic garden is part of an overall aim to reintroduce plants which are rarely or not at all present in the urban environment, despite the beneficial high potential for co2 sequestration inplants such as lemon thyme, wild chicory, as well as mallow.

Medicinal plants and their flowers contribute to pollination, which promotes the reproduction of plants and preserves bees in the urban environment. A physic or medicinal garden, also named in Latin: hortus-medicus, herbularius, erbarium-botanicum, hortus botanicus (the wider sense: botanical garden) is where plants with medicinal properties, also These often include herbs also used ascondiments, such as thyme, sage, balm and hyssop.



Stefano Morana del Medico


Jesus Pascual Diaz


Lucia Della Putta-Dallara

Technology Engineering

The  term aromatherapy covers various medicals practices using essential oils for application onto the skin , cream or lotions ( oil-in water  emulsions) for exert use. The dispersion in honey or in edible oil or simply on a sugar is usual for administration by the oral route,
in different galenic forms. Aerosols obtained by nebulization of essentials oils are more  rarely used ,but  the dispersion in the atmosphere of a room obtained by the use of specials diffusers is very widespread. Essentials oils are very concentrated hydrophobic liquids  and resins containing a volatile aroma compound from the plant.
Essentials oils are generally extracted by distillation by using steam. other process are fractional  distillation, solvent extraction, ( we avoid this solution as it is the less ecological) or supercritical CO2 extraction.
The practice and use of aromatherapy always requires  the advice of an informed and certified professional.
Some essential oils are very well tolerated pure on the skin,some others needs to be diluted  to 1/10  to  1/20 in a vegetal carrier .
The  properties of essential oils are multiples:
  • anti-infectives
  • antibacterial
  • antimycotics
  • antiparasitic
  • insects  repellent and insecticides
  • anti-inflammatory
  • antictarrhal /expectorant
  • anti-histamines
  • antispasmodic
  • analgesic
  • calming/ hypnotic
  • and anxiolytic
  • endocrine -regulating properties
  • digestive properties
  • antitoxic
  • antivenom
  • antirheumatic
  • carminative
  • cholagogue and choleretic

In the history of medicine and at least until the sixteen century, the history of aromatherapy is largely blended with  phytotherapy.
If we   find the traces of distillation extractions methods, in China and India, ( ayus-veda) back severals millennials , it is in Egypt that  their use  has  first  been proven.In ancient Greece, the writing of Dioscorides refers to the use of aromatic extracts. The Romans also used them in the form of oily ointments.
The Persian alchemist Jabir Ibn Hayman ( GEBER) was credited with  inventing the alambic and  allowing the production of the first  distillation quintessence in the  8th century A.D. Extraction processes subsequently improved with pharmacopoeias using them toward the sixteen century. it was only in the 19th century that the active principles of odoriferous molecules began to be isolated and classified, allowing their specific use.
In 1910, the chemist René-Maurice Gattefossé ( 1881-1950) who researched perfumery, burned his hands during a laboratory explosion . Very badly burned, and treated according to the means of contemporary medicine, he was rapidly affected with gas gangrene. As a last resort, removing his bandage, he applied lavender oil to his infected wounds. The results were astonishing and confirmed his intuition: the essence of lavender possessed real antiseptic and cicatrizing properties. From then on ,he devoted most of his research  to the properties of essential oils. In the 1960's Dr. Valnet ( 1920-1995) resumed the work of Gattefossé and published
in 1964 the reference book " Aromatherapy: treatment of diseases by plant essences".
Subsequently, Pierre Franchomme, with the notion of scientific chemotype, helped to improve the identification of active ingredients in the extracts used. They are both  considered the fathers of the modern scientific aromatherapy.
At the end of the 20th century, as with all pharmacognosy, scientific aromatherapy benefited from the advances in analytical methods, in particular chromatography . The  precise distinction of aromatic compounds allowed medicine to better understand their mechanism of action, and to refine their prescription.



A  Certified phytotherapist and  aromatherapist, Stefano Morana Del Medico, a founding member of a "UN JARDIN SUR LES TOITS", regularly associate the benefits of aromatic plants to most  of the agency and collective projects.
He  is deeply convinced that the active properties and the helming power that lies in the molecules of medicinal plants contribute to improve the well being of the users.
Aromatherapy implies the  use of aromatic compounds extracted from plants in the form of essentials oils for medical and healing purposes as a complementary therapy  or an  alternative medicine. this differentiates it from phytotherapy which make use  of all the elements of a plant : seeds, flowers, fruits ,roots .
Originally practiced according to a  traditional approach, as a branch of phytotherapy it  came s together along  the naturopathy disciplines and was classified as  non-conventional medicine. Increasingly studied by scientists, especially in the contest of pharmacognosy, which provides evidence for the properties os essentials oils,it can now be practiced according to the principles of evidence-based medicine by health professionals.
The term aromatherapy was used for the first time for the first time by the chemist  René Maurice Gattefossé in 1935.
It comes from the ancient  greek: aroma ( aroma)  and therapeia ( therapy).
There are many positive technical impacts on the realm of extensively planted terraces and roofs, they always seems to be positive:
Waterproof materials are protected fromUV rays and sunlight and have a longer life.
Indeed, the deterioration of waterproofing membranes is mainly due to heat and UV rays. They damage synthetic elastomers or the oil in elastomer bitumen which become fragile. The plant substrate block the UV rays which are responsible for 5% of the aging of waterproofing roof. It is therefore a protection against badweather. These effects combined prolong the life expectancy of the waterproof membrane by 30 to 50 years.
The building and their occupants are protected against thermal shocks (cold rain on a hot roof, alternation between day/night or sun/clouds) reducing mechanic constraints which cause cracks. Thanks to thermal inertia,green roofs have a temperature variation of up to 40%, permitting significant reductions in energy costs.Roof membrane exposed to the sun can reach a temperature of 65°C,whereas the same membrane covered with plants stays at a temperature of15 to 20°C. The roof temperature impacts on the building's indoor temperature, and therefore on the need for air-conditioning. A plant-covered roof with a substrate of lightearth also reduces heat loss in winter.
Plants and substrates are some of the best acoustic insulation, as they absorb sound waves, hence reducing ambient sound levels. A 12cm thick substrate reduces sound by up to 40dB - another worthy advantage for areas where planes fly over at a low-altitude.
Impact on landscape and environment
Carefully designed living roofs improve the aesthetic value of cities, and particularly industrial cities. They also add value to habitations which are integrated in the environment. If they are designed with this in mind, they can also contribute to the ecological network ( biological corridors, buffer zones, biological connection zones, substitutional habitats, ecological fords, etc).

Impact on health
The positive impact on health does not seem to have been (yet) scientifically measured , but certain indices indicate that it is indisputable. Additional vegetation on roofs produces additional oxygen for cities. The plants and substrates fix and filter many atmospheric pollutants, such as sulphur dioxide and nitrogen oxide; micro, and perhaps even nano particles. Plants, in particular due to dew, retain dust and allergic pollen,and reduce the quantity of particles suspended in the air. An example of this effect is the use by different scientific programmes of moss to analyse the cartography of air pollution, given their capacity to capture and fix even heavy metals.

Social Impact
Living or green roofs make a built-up environment more "calm", less stressful. Inhabitants and users rediscover a harmony between urban life and a natural environment.

Economic impact (costs/benefits)
With regard to financial aspects, the CSTB (Centre scientifique et technique du bâtiment), has estimated the following average cost: a garden terrace on the surfacearea, the slope, the selected plants,and eventual necessary reinforcement of the structure, an additional cost of the waterproofness makes this solution less expensive than a tiled or slate roof.
It is difficult to evaluate in financial terms the environmental advantages for man, as well as certain additional positive effects: for health, reduction in energy use, increase in life expectancy of the structure etc.
The substrate and plants provide additional isolation (mainly againstheat). Temperatures under the roofs fluctuate moderately, reducing heating and cooling (air-conditioning in summer) costs for living or circulation. Living roofs also reduce certain individual and shared costs: health,water resource management, cleaning for which the dust, due to the quantity and relative toxicity, begins to create problems for elimination and storage. Maintenance and repair costs due to flooding, pollution created by sudden rising waters caused by saturated ground, malfunction in grainwater networks, water-treatmentplants, etc. are reduced when plant life is increased on saturated surfaces.
A rooftop garden also provides an additional living space for occupants,adding value to property for rent or sale in an urban environment. A living rooftop terrace also adds prestige to an office building for the companies who have access to it, adding a social and environmental engagement to any company sustainable policy.


In France, we work on buildings certified HQE® (High Environmental Quality), H & E (Habitat & Environment), BBC effinergie (Low Consumption Building), Passivhaus and BEPOS (Positive Energy Building). At the international level, we work with BREEAM and LEED certification.

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Created in the 1990s in the United Kingdom, it is the oldest repository in terms of sustainable construction. With more than 250,000 certified buildings worldwide, BREEAM now has international visibility.

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LEED® certification, Leadership in Energy and Environmental Design, is an environmental certification for buildings initiated in the United States in the year 2000 by the US Green Building Council®. More than 100,000 LEED projects are certified or currently being certified in more than 120 countries. Each level requires a minimum of points:

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The "Grenelle Environnement 2012" thermal regulation, known as RT 2012, is a regulatory tool for new residential and tertiary buildings. It aims to improve energy consumption by setting a maximum limit.

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The WELL Building Standard (WELL) focuses on the people in the building. Over the last decade, green building standards and standard-setting organizations have made significant strides towards the market transformation of the building industry, resulting in a rapid expansion of green buildings and environmentally conscious building practices throughout the world.

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