Challenges of Hyperdensity and Vertical Urbanism

Hong Kong has one of the densest urbanized areas in the world. Densification has been consistently pushed higher over the last 50 years. From the traditional chinese shophouse dwelling which barely exceeded two stories and created a low rise high density, the density in metropolitan areas of the city reaches for domestic use alone up to plot ratio 10 nowadays.

While the traditional urban density consisted of low rise high density structures, a building had a large surface as space, serving as a public interface and semi public realm. In urbanized areas buildings were mainly shophouses with 2-4 floors of which the ground floor was commercial and public space for the inhabitants of the building. Its floor ratio of public and private space was around 1:1.

The challenge to the densification of the city is not the fact that buildings get taller. The challenge is the ratio of public space to private space, which disadvantages the public space exponentially. Even more, the building codes favor prescriptive measures to maintain public spaces (indoor or outdoor alike) at the bottom 4-6 floors. It implies that the city is not divided anymore by the plan layout of roads but by a sectional division of a small and condensed public city below 6 floors and a massive private city up to 50 floors above that datum. The floor ratio between private space and public space (as per maximum allowable number of floors for each area) shifts to a 12:1 ratio in the current metropolitan environment. As street profiles remain the same within redeveloped areas, the increased density affects the quality of the urban environment.

The implications on the city are huge and visible all over the city. Recent transformations are accelerated by the construction of new MTR lines around the city. The effects of the density are affecting especially those old areas of the city that have evolved along the hillsides: Smaller streets and thinner blocks are dictated by the topography. A random urban quarter in Sai Ying Pun around the Centre Street Market - one of the oldest districts in Hong Kong - shows the dramatic effects of the density increase in relation to the narrow road network:

The pressure on the street and the ground floor level as a last resort for public space for an dominating privatized city above is immense and leads to a deterioration of the built (and unbuilt) environment. 

Yet the basic sectional configuration (of public and commercial space on lower floors, private space above) has remained the same up to today, the ratio has shifted dramatically in favor of the private space. 

The question arises if the regulations are too traditional for cities that shift towards a high density environment? Particular in Hong Kong, the reality of the regulations is of prescriptive nature rather than descriptive, leaving little room for flexibility and adaptability of architecture. 

Understanding the commercial driving force behind the maximization of private (sellable) space, yet with limited space for public and commercial activities left, the management and distribution of those should be revisited and made more flexible in favor of a better sectional condition of the vertical cities. 

Being great supporters of hyper densification of our metropolitan environments, our design practice is always confronted with the limitations of the building codes and their simple plan oriented codes. The acceptance the plan itself as the main planning guideline ignores the complexity of high density environments; a complexity which affects plan, section, profiles in a more challenging way with way more negative side effects than it would do in a low density environment.

The question remains why vertical and sectional zoning has not been introduce yet as guidelines for a high density environment. For the benefit of improved living conditions and better urban environments, two dimensional planning has to consider more the reality of three dimensional potentials. Vertical Urbanism has been the focus of our commercial practice as well as of our academic research.

Solutions we are currently investigating as a feasibility study are the potentials of updating sectional planning parameters for high density environments, such as introducing a verticality ratio as well as vertical parcel lots:

© 2013, ice - ideas for contemporary environments

Reflections on the City in sizzling summer heat

With the summer heat reaching a peak at around 40 degrees and 95% humidity, it is time to escape the narrow, stuffy lanes to take relief on breezy peaks in the shade of large subtropical trees. Ascending to Mount Parker and the fantastic views it creates from its peak, it demonstrates again the quality, the city provides. The city planning not only fascinates from above, but the entire fabric amazes through its compaction and densification on all scales and stages: It is not only the dense build environment (which has stimulated and inspired futurists and cinematographer alike in terms of a darker take on the future), but furthermore the closeness to dense raw nature just five minutes away from the city. It is an invasive and mutual relationship between the city and its nature. While nature has been fought in the past and tried to be controlled for the most part of the city development, there is a shift in understanding on how the relationship could be beneficial.

But are we on the right track towards a greener city, more sustainable city, or do do we miss the chance by simply applying western ideas of beautified landscape to the urban fabric?

It is true, that the tropical nature is way more invasive and destructive to architecture, than, say tempered environments. Not only in terms of plant growth, but also in terms of pests. Yet the chance lies exactly in its rawness and ever rejuvenating force. Because of Hong Kong's geographic unique situation of being of volcanic heritage, the city had to evolve around many smaller peaks, most of them too steep and too large to be inhabited. They left natural corridors with a rich fauna and flora just next to the city. The mistake, which has been done in the past, is to cut off the connections to the nature next to the city, trying to tame the nature within the urban environments to become maintenance intensive spots of green, manicured islands, resembling the western suburb: pretty to look at, not to use. The finger like connections, which stayed intact, remained mere accidents because of the volume of the topography and high costs of removing them.

The chance for Hong Kong lies in reinstating the finger connection to its nature, introducing a more sustainable element of wild into the urban centers. Similar to the (on paper only) garden city vision for the urban renewal of Rotterdam in the 50s, which introduced green corridors, creating un-interupted connections between city and nature and an improvement of the climate, Hong Kong could use the strength of its tropical nature, to introduce green channels, which allow fauna and flora exchange, improved climatic exchange and a secondary circulation network for leisure and recreation.

Other than a manicured nature, the local wild species are in less need to be maintained. In fact, their intense growth introduces the need to cut them back constantly. Introducing a wild corridor would reduce the need for maintenance and increase the self sustaining power of such environment.

Those thoughts come through my mind on a hot summer day up on the mountains, where the environment is so much better than down in the environment, created by us. Even if it appears to be not feasible for now due to mainly economic pressure within the city, we will launch a research project on nature highways and wild corridors soon....

© 2010, ice - ideas for contemporary environments

Back to EPFL

After having taught a Masters Studio in Lausanne last Winter Term, I am very excited to go back to Switzerland in March. Giving two lectures about contemporary typologies in architecture, one at the ETH Zurich and the other one at the EPFL Lausanne, I am also looking forward to visiting the completed Rolex Learning Center by SANAA (and maybe I will be lucky to give the lecture there).

The subject of the Masters Studio was: Sustainability and Density - Contemporary Typologies in Architecture. The design project was putting emphasis on dealing with complexity: The project was a high density mixed use development in Hanoi. The complexity was not only related to the amount of program but also the climatic difference and the completely new social and cultural environment - a tough but fruitful journey for the students...

The research has been focussing on two main aspects: How density will affect typologies and their transformation in such a compact spatial scenario. And about low-tech spatial strategies for sustainability.

The purpose of this studio is to bring back a more expansive view of Architecture, to refocus energy into the larger context of living, especially in the understanding of how others live and use spaces. To simultaneously create and be created by the forces of the context, architecture is no longer an object, but also a subject in the larger scheme of things. We want to design buildings, that are not just form, but perform.

With the building boom particularily in the emerging markets, there has been a run for high density mixed-use developments. Unable to bridge the scalar gap to the existing context, we have seen a lot of brilliant solutions of self referential projects, but the overall built environment is increasingly mismanaged: Ignorant to the environment, program and climatic parameters, high density developments pose quite often severe challenges to the city, such as canyon and heat island effect, social segregation, and economic pressure. With such development pressure of iconic high density structures, architecture is produced as an object of desire, rather than a space to be inhabited and used.

Team: Ulrich Kirchhoff, Louise Low

Students: Gedeon Abebe, Esteban Becerril Pellon, Olivier Genetelli, Pablo Gironda, Riccardo Grattacaso, Marta Lopez de Aisain Gamazo, Romain Lorenceau, Marta Lozano, Mansour Noverraz, Adrien Renoult, Julie Riedo, Erika Tillberg, Toru Wada