Rooftops, redesigned

Rooftops, the most panoramic, sun-washed, and valuable parts of urban real-estates, serve currently as functional spaces. Is this paradigm about to change?

Rooftops are a largely underutilised part of the urban landscape, often simply fenced off and used for functional and practical purposes. However, as guessed by Le Corbusier in his Five Points of Architecture, rooftops can be transformed into elevated parks that provide a variety of benefits to city dwellers, including better access to green spaces and dramatic viewpoints, lower urban noise and heat, and additional playful pedestrian routes.

The rooftops of our cities are often overlooked, relegated to the background as a mere functional aspect of buildings. However, there is a hidden world of potential lying just above our heads, offering sun-drenched spaces and stunning views of our urban landscapes — an untapped potential to transform the urban experience for residents and visitors alike.

Rooftops are increasingly becoming functional spaces

Opportunities exist for both old and new neighbourhoods. Old neighbourhoods could be retrofitted to create monumental green highways in dense, busy city centres. New neighbourhoods could instead include a vision for green rooftops and green highways natively into the projects, possibly spanning through multiple adjacent developments to create a linear, stretched green park.

Rooftops are increasingly becoming functional spaces

Breakdown of a dual-layered urban development, where a system of parks, bridges, and facilities transforms the most valuable part of the city in active urban spaces.

The concept of a rooftop network involves creating interconnected pathways, gardens, and leisure spaces on the roofs of buildings within a city. This new urban space would offer numerous benefits, including:

Additional green spaces and access to sunlight. Rooftop gardens and parks can provide much-needed respite from the concrete jungle, offering natural environments for relaxation and recreation. This is particularly true in dense urban areas with little public green. Additionally, a great deal of sun-washed surface is given back to the public.
Additional pedestrian areas. Rooftop pathways can ease congestion and provide alternative routes for pedestrians in busy urban areas, reducing the need for ground-level road space. For example, there could be the opportunity for pedestrians to bypass road crossings, or to create new access routes to train stations, office buildings, or museums.
Stunning city views. Rooftop spaces can offer unparalleled views of the city, creating unique and inspiring environments for residents and visitors.
Access to functional buildings. Rooftop networks can facilitate direct access to cinemas, museums, and shopping centers, enhancing convenience and ease of movement.
City playfulness. Breaking the standard of the ground-floor-only pedestrian circulation, a multi-layered city allows for a more playful urban environment, with terraces, viewpoints, bridges, and tunnels through buildings, adding to modern city aesthetics.
Noise and heat reduction. Some studies show that green coverage on top of buildings can help absorb traffic noise and solar heat, reducing noise and temperatures.

A conceptual view of a rooftop pedestrian public corridor.

To create an effective rooftop network, certain prerequisites must be met:

Flat rooftops. The majority of buildings must have flat rooftops to accommodate the proposed pathways and green spaces.
Similar building heights. Buildings should be of similar heights to allow for easy and safe connectivity between rooftops.
Close proximity of buildings. Buildings must be situated close enough together to enable the creation of continuous rooftop pathways.
High traffic and need for additional road space. The rooftop network should be implemented in areas where there is significant pedestrian traffic and a clear need for additional road space.

We worked on a conceptual example for the city of Amsterdam: Amsterdam High Park. This independent, speculative project envisions a public rooftop park, stretching from the busy Flower Market on the Singel canal, to Rembrandtplein, in one of the busiest parts of Amsterdam. The green corridor would connect the rooftops of a number of buildings — TNW, a NH Collection hotel, 2 Pathé cinemas, and some private buildings —, thus creating an additional park right in the city centre of Amsterdam, currently lacking green spaces.

Conceptual drawing for Amsterdam High Park, a public park streching through the rooftops of NH Collection hotel, TNW, and the Pathé cinemas. A number of facilities, linked to the "hosting buildings", could be created within the park, boosting the link between the rooftop park and the buildings underneath. For example, the TNW coworking space could extend working stations into rooftops pods and greenhouses; NH Collection hotel could curate a rooftop bar open to the public; Pathé cinema could host rooftop cinema screenings in summer.

The development of a rooftop network would require extensive collaboration between local governments and private property owners. This unique endeavour would necessitate the creation of a public space that is closely intertwined with private properties. Through careful planning and negotiation, the implementation of a rooftop network could revolutionise the urban experience, creating green pedestrian highways, and unlocking the benefits of a multi-layered city.

Special attention should be put into the creation of similarly-tall buildings and/or the predisposition for the future implementation of pedestrian corridors across buildings, for a unified approach to emerge.