Transforming untapped pitched roofs into green and accessible spaces
Roofscapes transforms untapped pitched roofs into green and accessible spaces as a way to mitigate urban heat islands, anchor biodiversity, catch storm water, and provide new outdoor spaces in European city centres. Thanks to prefabricated timber modules and without demolishing existing buildings, Roofscapes helps European cities adapt to our century’s social and environmental challenges.
In talks with several additional municipalities and regions in France and in other countries (Croatia, Switzerland, Italy)
It refers to a physical transformation of the built environment (hard investment)
As a representative of an organisation
Name of the organisation(s): Roofscapes Studio Type of organisation: For-profit company First name of representative: Eytan Last name of representative: Levi Age: 26 Please attach a copy of your national ID/residence card:
By ticking this box, I certify that the information regarding my age is factually correct. : Yes Gender: Male Nationality: France Function: Co-founder Address (country of permanent residence for individuals or address of the organisation)<br/>Street and number: 6 square Alfred Dehodencq Town: Paris Postal code: 75116 Country: France Direct Tel:+33 6 95 66 79 59 E-mail:email@example.com Website:https://www.roofscapes.studio
Roofscapes was launched by 3 French students at MIT in the aftermath of the 2018 and 2019 summer heatwaves, at the time the hottest on record in Europe. In addition to global warming at a continental scale, cities around the world are threatened by the urban heat island effect, a phenomenon through which urban areas experience higher temperatures than their surrounding rural areas (eg: +8°C in the center of Paris compared to the countryside 40 km away) due to the lack of vegetation in cities.
Since a widespread deployment of air conditioning would itself lead to an additional temperature increase during heat waves, the issue of passive cooling in cities is a question of urban and territorial resilience. The desartificialization and greening of cities are recognized as two of the best levers for action against the urban heat island effect. However, the densest urban areas in Europe, which suffer the most from urban heat islands, offer little free space for vegetation on the ground. Moreover, while roofs cover 30% of the horizontal surface of a city like Paris, the vast majority of buildings in European city centers have a pitched roof, making it impossible to install a traditional green roof.
Roofscapes' mission is to turn these untapped surfaces into green and accessible spaces in order to allow several billion square meters of European rooftops to fully participate in the mitigation of environmental issues and the reinforcement of social cohesion. Roofscapes transforms existing pitched roofs through the installation of mass-timber prefabricated platforms that welcome vegetation as well as human and non-human species.
Having a positive sustainable impact is Roofscapes’ purpose. Below are the key sustainability objectives of Roofscapes:
1. Climate change mitigation and adaptation: By participating in the passive cooling of city centers through shading heat-absorbing rooftops with planted surfaces, Roofscapes reduces the surface and interior temperature of buildings, thus providing more comfortable living environments for urban residents and diminishing the deployment of air conditioning systems with high electrical loads and heat emissions.
2. Water retention: By capturing rainwater, Roofscapes helps spread the load on urban water networks during storm events and ensures plants stay alive during droughts.
3. Land artificialization: By improving the quality of urban environments, Roofscapes helps create more livable cities, thus reducing the exodus to rural areas and the ensuing artificialization of agricultural soils.
4. Protection and restoration of biodiversity and ecosystems: By creating new green anchors at the roof level that welcome pollinating insects and birds, Roofscapes provides new habitats for urban wildlife and contributes to the resilience and continuity of urban biodiversity.
5. Pollution control: By increasing the presence of vegetation and soil in cities, Roofscapes helps filtering certain air pollutants and stormwater, contributing to improved air and water quality.
6. Transition to a circular economy: Roofscapes focuses on the reuse of materials on its projects, for both structural and non-structural elements.
7. Local food production: By enabling additional surfaces for urban farming, Roofscapes contributes to a shift towards increasingly local food networks.
Roofscapes provides a holistic approach to the sustainability challenges faced by cities as it addresses several issues that have been overlooked in the conventional maintain vs demolish paradigm of urban development.
Sustainability should go hand in hand with pleasing design and human experience. Below are key objectives of Roofscapes in that direction:
1. Accessible infrastructure: Although most rooftops are currently unused in European cities, they could host several programs, from energy production to urban farming. Roofscapes believes that urban infrastructures like rooftops should be made accessible to human beings as a way to provide additional outdoor spaces in crammed city centers. Roofscapes’ internal chart prescribes at least 70% of soil & plant occupation on its platforms, with the rest designed to be accessed by human users.
2. Spaces for social cohesion: Urban dwelling has been characterized by the decline of social interactions within housing and office buildings. Roofscapes offers new spaces to building users without affecting indoor occupation. Neighbors and coworkers finally have a place where they can gather and meet each other.
3. Highlighting heritage through accessibility: Countless European cities are praised worldwide for their heritage. At the roof level, however, such heritage is rarely perceived as rooftops are mostly inaccessible in European cities. By enabling the general public to penetrate those spaces, Roofscapes supports heritage preservation by making all citizens aware of it through a physical and visual experience.
By accelerating the greening of the built heritage without destroying it, Roofscapes seeks to strengthen the social and environmental resilience of European cities against the challenges of our century, without compromising on the aesthetic component of this transition.
Adapting exiting buildings implies regulatory, financial and physical challenges. Below are key objectives of Roofscapes to overcome them and provide the most inclusive offer:
1. Rooftops for all: Roofs are currently only accessible by those who own the spaces below them and those who practice urban exploration illegally. By offering secured timber platforms accessible to everyone in a building (and sometimes open to visitors as well in the case of publicly-owned buildings), Roofscapes challenges restrictions on rooftop access and contributes to the creation of a new lifestyle. People with physical disabilities are obviously included whenever elevators can be technically extended all the way to the rooftop level.
2. Cost reduction through shared access: Instead of creating expensive spaces only used by those living on the upper level of European cities, Roofscapes favors an approach in which dwellers from all floors pool resources together to fund a space they can all share and access.
3. Positive revenue streams: As some buildings might not be able to fund rooftop platforms by themselves and as subsidies are limited, Roofscapes offers several avenues to generate a positive cash flow and fund projects: rooftops can host cafés and other outdoor activities for external visitors, sell parts of their urban farming production or generate renewable energy.
4. Participatory design & planning: Whereas Roofscapes uses a similar approach for all projects through mass-customization, its platforms are able to adapt to hyperlocal conditions, such as the presence of a skylight or particular access paths. In every project, Roofscapes works with users, tenants and building owners to ensure that everyone’s needs are reflected in the design.
5. Roof-level network: Roofscapes’ long-term vision consists in developing a rooftop network complementing street-level circulation and spaces, through which new social opportunities for under-included audiences can emerge.
Ever since the inception of Roofscapes, user studies have been conducted with dozens of potential users, condominium associations and building owners in Paris and other European cities such as Zagreb, Venice, Zurich, Marseille, Toulouse or Bordeaux. In parallel, companies and professional organizations have been consulted to optimize the concept. Several changes have been reflected into the design of Roofscapes following these conversations:
1. Security and access: Citizens have voiced their concern about who gets to be on the rooftop at a given moment. As a result, Roofscapes will include electronic locks on rooftop access so that access can be collectively regulated by the building association, with open and restricted slots.
2. Maintenance: Citizens have expressed various levels of commitment when it comes to taking care of their roof gardens. Roofscapes is now considering several options, ranging from rooftops fully maintained by their users all the way to hiring external gardening companies or associations to provide routine maintenance at a predefined frequency.
3. Ownership & cost distribution: Citizens are curious about who owns their rooftops once it becomes accessible. Roofscapes is now proposing two ownership models based on each project’s cost distribution: on the one hand, collective ownership by the building association, on the other hand, private ownership by the upper-floor owners with a limited right of access for other tenants or owners throughout the year.
4. Programs: Citizens have come up with unexpected requests when it comes to utilizing their rooftop. Through several design workshops, Roofscapes has received dozens of ideas, from gardening to yoga, through rooftop dinners and biodiversity fallows. The design of Roofscapes’ projects now makes it possible for most of those programs to coexist on any rooftop.
Today, Roofscapes receives on average one feasibility request per week through its website, which keeps enriching the concept.
Roofscapes has sought advice and permissions since the very beginning from various stakeholders at multiple territorial levels.
1. Government: Roofscapes was initiated in Paris in the aftermath of the Mayor’s Office call for additional vegetation in the city. Ever since, exchanges with numerous politicians and public administrations at the city level (eg: city departments of green spaces, of urbanism, of public works, of fire safety, of architecture and preservation, etc) have generated pragmatic adjustments to the concept. The Roofscapes team realized early on that a project affecting the external aspect of buildings was, in fact, a political project that required decisions at a national level (and perhaps at the EU level) to favor adaptation to climate change over an ideological preservation of existing buildings that doesn’t take into account the shifting climatic realities of our era. Several meetings have already been organized and more are scheduled in the next few months at a regional and national level to advocate for the realization of Roofscapes’ first pilot projects.
2. Companies: Roofscapes is engaging manufacturers and installers at a regional level from the sourcing of timber used for its modular rooftop platforms all the way to the maintenance of rooftop gardens. At the European level, Roofscapes has established relations with companies in several countries (Netherlands, Germany, Switzerland, Italy, Denmark, Belgium) to exchange on best practices, develop mutual inspiration & learning opportunities and overcome similar challenges.
3. Citizens: As Roofscapes is first and foremost targeting private customers (be it individuals or companies), the needs of human users have been considered in the concept design since the very beginning. This research work began in Paris and has extended to other cities since then in order to develop specific adaptations to local climatic, geological or architectural conditions.
The core team of Roofscapes is constituted by three friends who met during their architecture studies. They eventually drifted towards complementary expertises, respectively in real estate development & urban planning, in timber fabrication and in sustainable construction.
Along these knowledge fields, other disciplines were involved in the development of Roofscapes:
1. Design: Roofscapes worked with consultants in user-centric design as well as with structural engineers to ensure the feasibility and inclusiveness of its concept from the earliest design phases.
2. Construction: Roofscapes integrated early feedback from roofers and carpenters in order to ensure the safety and lifespan of each rooftop.
3. Maintenance: Roofscapes engaged with numerous urban farmers and landscapers in Paris and throughout Europe to understand the operational challenges linked to vegetation on rooftops. Real estate developers and corporate owners were also brought in to raise any challenges they could foresee with green roof projects on their buildings.
4. Advocacy: Roofscapes involved professionals from the public affairs world to refine its outreach strategy with elected politicians, public administrations and the media. The resulting interactions with local, regional and national governments opened up new design possibilities that the Roofscapes team had previously rejected internally.
In addition, more traditional roles (accounting, legal…) took part in the development of Roofscapes but have played a limited impact on the concept so far.
The deeply collaborative process behind Roofscapes strengthened the concept’s design and development. The core team also realized throughout this process that although all the necessary knowledge to implement its concept already existed, there was a lack of coordination between all players. That is precisely the space where the Roofscapes team now operates, in addition to generating the initial vision and concept.
Roofscapes has emerged from two distinct innovations, respectively at the physical level (disruptive innovation) and at the organizational level (architectural innovation).
1. Disruptive innovation at the physical level: As cities around the world are increasingly threatened by the urban heat island effect, vegetation has been recognized as one lever to mitigate temperatures in cities. However, many European cities have limited available surface for vegetation at the ground level in their densest neighborhoods and their rooftops are generally not suited for traditional green roofs, since most buildings are covered by a pitched roof. Roofscapes hence stems out of the need to deploy green and accessible rooftops over pitched roofs to leverage the role of unused rooftop spaces in cities without destroying heritage buildings.
2. Architectural innovation at the organizational level: Contemporary contributions to the built environment, be it in architecture, urban planning or landscaping, often start from scratch for each project. Roofscapes believes that a more systemic approach is required to maximize the built environment’s adaptation. As copy pasting the exact same product is not desirable either, Roofscapes follows a mass-customization logic for its projects: the same constructive approach is deployed on similar but never identical buildings. Once load-bearing walls have been located, zinc or tile external layers are punctured to allow for the installation of columns to ensure structural continuity. Glued laminated timber beams are then installed, supporting prefabricated timber slabs before the installation of handrails and the opening of necessary accesses. Finally, planted surfaces with automatic watering are deployed, along with rainwater storage systems whenever structurally possible.
The vision and implementation process do not change from one project to another while the physical elements are adapted to local conditions.
As mentioned previously, the vision and the mass-customization approach behind Roofscapes make the concept easy to replicate in different contexts, in Europe or elsewhere. A number of differences need to be considered in such cases, especially regarding architectural typologies, ownership structures, local companies and decision makers, rules for heritage preservation, available funds, water supply, energy production potential, timber sourcing and native vegetation.
Although differences exist and contribute to the specificity of each location globally, the overarching global need for greener cities added to the inadequacy between existing buildings in European city centers and ongoing environmental changes make it necessary to implement and duplicate concepts like Roofscapes.
1. Climate change: Roofscapes addresses the issue of global warming by enhancing passive cooling in cities. By replacing high thermal conductivity materials, such as zinc (λzinc = 110 W/mK), with organic layers of timber, earth, and vegetation (λtimber = 0.20 W/mK), Roofscapes reduces surface and interior temperatures. The use of timber instead of zinc results in shading and reduces the absorption and reflection of solar radiations by rooftops, ultimately reducing the urban heat island effect.
2. Building adaptation: The existing built environment in European cities is not well equipped to handle future environmental challenges. Instead of replacing old buildings with new, more efficient ones, which is wasteful and carbon-intensive, Roofscapes seeks to adapt existing buildings through tactical interventions, avoiding material waste and preserving energy.
3. Land artificialization: Urban residents and workers face a lack of quality outdoor spaces and may move to less densely populated areas in search of greener environments. This contributes to land artificialization (eg: 25k hectares are artificialized each year in France, 4x the population increase). Roofscapes provides desirable, green environments in cities to curb the urban exodus.
4. Biodiversity erosion: The widespread use of artificial materials with high thermal conductivity in cities has led to the disappearance of urban biodiversity. Roofscapes aims to create new anchors for non-human species that support wildlife continuity.
5. Food production: To decarbonize agriculture, supply chains must become more local. By providing access to all urban rooftops, Roofscapes enables the creation of more urban farming spaces.
6. Water supply: Roofscapes' projects are covered with 25cm-deep planters with soil that retain storm water and spread the load of sewer systems.
7. Social inequalities: Roofscapes seeks to democratize rooftop access by providing new outdoor spaces for social encounters between all citizens.