Roofs are conceived as the final layer of an architectural entity, an essential shield to protect against the external environment, thereby defining its form and materiality in response to the local climate. With time, the roof evolved not just as a protective cover but as an architectural feature that defines a place, giving it a distinct character, thus becoming a cultural marker. 

The function of the roof changed as well, from a mere shield to a space that hosted a variety of activities, a place to socialize, a place to seek refuge and a haven to experience serenity at an elevated surface. Therefore, the roof became an inseparable part of the architecture and social culture of a place, an extension of urban life onto the surface.

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The new gardened roof of Facebook Menlo Park, California_©Inhabitat

In dense concrete jungles, with bland monotonous blocks, roofs act as an escape from the dull, hectic city life where the idea of retreating to a higher level seems appealing. With cities growing at an exponential rate and real estate value reaching its peak limits, the conventional linear and horizontal growth has been deemed unsustainable and degrading, thus resulting in a need to rethink roofs in a radical manner where instead of being perceived as the top layer, they are imagined as a base for a new layer, thereby giving new meaning and purpose to it.

Rooftops represent 25% of the city’s total land area, thus establishing its place as a significant part of the urban fabric. Ironically, the majority portion of such a prominent spatial resource is left unused or not used to its full potential. From sustainable framework and roof gardens to cultural and social spaces, activating rooftops as an added layer to the urban tissue is an emerging topic in the subject of city sustainability and resiliency.

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Building rooftop gardens in Barcelona to fight climate change_©

The most common way to put existing rooftops to good use is through green roofs, water management systems, energy efficiency systems and urban farming. The benefits of green roofs are immense, to alleviate urban heat island effects, collect stormwater runoff, reduce air pollution levels and foster biodiversity by encouraging the local flora and fauna, thus eventually leading to an improved urban landscape and enhanced quality of life.

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Hanging Gardens of Babylon_©TheIndependent

The concept of rooftop gardens is not radical, it has been present since the Mesopotamian civilization where the ancient architectural marvel of Hanging Gardens of Babylon featured stepped landscaped terraces, connecting the ground to the roof garden, thus forming a flourishing oasis in the middle of a desert. Roof gardens serve multitudes of purposes such as an extension of the living areas, a place to interact, a place to grow food, an environmental barrier, collection of rainwater and so on. 

Moreover, rooftops also frame the opportunity of urban farming, a requisite for a more sustainable future where reliance on external sources for food will be eliminated thus, resulting in self-sustained neighbourhoods.

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Thammasat University, Bangkok, Thailand-Largest Rooftop farm in Asia_©worldlandscapearchitect

The idea of green terraces is still being explored at a much larger scale, thus promoting the practice of sustainable architecture at the city level. The building codes of certain cities have already highlighted the sustainable use of rooftops in the face of climate change; Copenhagen has mandated the use of green roofs in newly constructed buildings since 2010, Barcelona is actively re-evaluating existing rooftops to set up sustainability infrastructure throughout the city and develop urban resilience. 

The City Council released a set of guides stating the guidelines and technical parameters to educate the residents about the different types of green roofs and the functions that could be incorporated alongside.

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CopenHill, Denmark_©theurbandevelopment

ROEF Amsterdam

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ROEF Amsterdam Festival_©

ROEF Amsterdam is an initiative that embraces the urban landscape through roofs thus, setting the city in motion. It not just offers the opportunity for sustainable energy demand and climate adaptation but also provides a public space for the citizens to enjoy and relax in dense urban spaces.

For cities that are in a constant state of flux with no further space to grow, adapting to this change is crucial. Change is inevitable but the answer to how architecture can adapt to this and innovate new solutions for densification of cities is where the idea of rooftops as means to expand vertically comes into play.

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Tunesian Village, Radetzkystraße, Vienna_©

Radetzkystraße – A village on the roof

Insertion of a series of cubic apartments was made on top of a 19th-century building keeping in mind the parameters of safety and privacy. Thus, the project explores the possibility of infill developments as a medium for urban densification. This project is one of the examples towards the goal of compact, sustainable cities where instead of hindering the natural systems by building on a new parcel of land, an unused space was utilized, thus, challenging the notion of horizontal development.

Rooftop architecture holds the promise of a more sustainable future, a wide array of possibilities yet to be explored and implemented, thus paving the way for an absolute urban transformation.


Andreea Cutieru. “A New Layer of Public Space: The Case for Activating Urban Rooftops” 05 Apr 2021. ArchDaily. Accessed 30 May 2021. <> ISSN 0719-8884

Zamperini, Emanuele & Lucenti, Simone. (2014). Symbiotic architecture: rooftop additions on existing buildings. 10.14575/gl/rehab2014/121.

Matt Alderton. “Life On High: the Renaissance of Rooftop Spaces is Here to Stay” 18 Dec 2018. ArchDaily. Accessed 30 May 2021. <> ISSN 0719-8884




Surabhi is a student of architecture and is trying to figure out how she can contribute to the field and society. She finds architectural writing as an escape to a world full of possibilities and hope. Her curiosity, zest to learn, explore and share, is what keeps her going.