Cities of Repetition: Hong Kong’s Private Housing Estates

Principal Investigator: Jason F. CARLOW (Co-PI), Christian J. LANGE (Co-PI)
Funding body: HKU Small Project Grant; FoA dean’s start-up fund


Throughout the 20th Century, in Hong Kong and around the world, the prefabrication of standardized architectural elements has enabled builders, governments and developers to increase the scale and pace of construction. During the influx of new residents to Hong Kong in waves throughout the mid-20th Century, new high-rise housing types were invented and built all over Hong Kong. The housing produced was tall, dense and standardized and built to house as many residents as possible as quickly as possible. While the history and architecture of public housing has been well researched and documented, relatively little has been done to trace the evolution of Hong Kong’s private housing estates.

The Cities of Repetition project provides a comprehensive graphic documentation and analysis of the largest Hong Kong housing estates built by private developers from the late 1960’s through the early 2000’s. The original drawings and diagrams illustrate and compare the ultra-dense, mass-produced, highly repetitive built environments in which tens of thousands of Hong Kong residents live. Drawings and plans not only display the immense scale of the housing estates within the city, but also present the hundreds of similarly planned housing units and their subtle differences. The exhibit and larger research project present a comprehensive analysis of the architectural and spatial realities of some of the most densely populated, urban environments ever built.


The project sets out to document degrees of repetition and standardization across Hong Kong’s largest housing estates and to visualize the close relationship between building code and building form in profit-driven housing projects.


The project shows that most all of Hong Kong’s largest housing estates share a single tower type with minimal adjustments for site conditions or unit variation. Over the course of the late 20th Century tower blocks became more repetitive as land value increased, code restrictions became tighter, advances in structural engineering allowed buildings to become taller and design was digitalized.


  • Exhibition, Cities of Repetition: Hong Kong’s Privately Developed Housing Estates, July – August 2015, HKU Shanghai Study Center, Shanghai, China
  • Lecture, AA Symposium, “Cities & Specificities, AA Visiting School Shanghai, Shanghai, China.
  • Book (Forthcoming) Cities of Repitition: Hong Kong’s Private Housing Estates, co-authored book with Christian J. Lange, (in contract negotiations with publisher).

Anticipated Impact

The project forms a critical graphic history of the densification of Hong Kong over the last 50 years. Broader publication will provide architects and urban designers across China, East Asia and the world with examples of extremely dense development and warn them against the possible dangers of overly standardized and monotonous urban environments.


Hong Kong Single Occupancy Strip

Hong Kong’s political system, geography and population density make it one of the most crowded urban environments in the world.  Skyrocketing real estate prices fed by profit driven developers and a deluge of investment and speculation from the Chinese mainland have made it increasingly hard for individuals in Hong Kong to afford an apartment.  In reaction to the increasing cost and shrinking size of Hong Kong housing units, the HK:SOS proposal presents a critique of contemporary development in the form of a super thin housing unit.  The project explores the challenges and limitations of living in minimally sized spaces by producing a linear apartment for a single individual.  By packing life’s quotidian activities into an impossibly thin strip, the project pushes the design of a domestic environment to a spatial extreme.

The project was initially investigated by “unfolding” a typical high-rise, Hong Kong apartment building into a linear array of rooms along the façade of the building.  In the project, axonometric drawings and physical models were constructed to test the idea of a long, linear building.  Bay windows, laundry racks and air conditioner platforms project from the exterior while furniture, room partitions and spaces for living project inward.  The result is a thickened strip of exterior and interior space that the project uses as a conceptual platform for design.

In the HK:SOS project, spaces for living, dining, cooking, bathing and sleeping are strung out in a linear array of micro-rooms.  Domestic activities are pushed into projecting window volumes that position the occupant precariously between a residential interior and the city outside.  The various rooms of the apartment unit are designed to be pre-manufactured out of concrete for exterior surfaces and thermo-formable, DuPont™ Corian® for interior surfaces.  Window units are sized and oriented in response to each domestic activity and are angled and inflected inwards and outwards to adjust for privacy or views.  Room types can be sequenced differently on each floor according to the desires of the occupants.  Units are stacked on top of each other to create a building that could be attached to the blank walls of industrial or commercial buildings to take advantage of highly valuable, underutilized space in the city.

Joint Studio with Columbia University

This joint studio between HKU and Columbia University’s GSAPP asked students to consider the long term impacts of industrialization on the natural and built environment. The studio considered the disturbed and derelict environments of industrialization and its “stuff.” Students sought to identify, research, record, and analyze an industrial activity and its impact on the social and geographical context. They were responsible for summarizing, cataloguing, diagramming, and/or mapping each process and productivity of the activity and its associated manufactured landscape.

Students identified sites (in Asia or worldwide) that have been impacted by industry or manufacture in extreme ways. Through in-depth research of speculative precedents, studio participants invented new scenarios and programs for these environmentally disrupted sites and tested their proposals through an architectural intervention. Working in teams, students began to speculate on potential programs and interventions that might tolerate or benefit from these disturbed and derelict environments. They inserted new architectural catalysts to add value or perhaps a different type of improved productivity within each local and global context.

Students were asked to broaden their view of industrialization, to re-focus their investigations on the entire cycle of manufacture, consumption and waste. They considered the consequences of present day production in the future and designed projects that acknowledge and anticipate “productive,” post-industrial outcomes.

Final projects were sited in remote regions of China, post- industrial sectors of Taipei, an abandoned factory in Detroit and in areas within the Pearl River Delta. They addressed diverse issues such as air and water pollution, electronic waste disposal, adaptive reuse of industrial structures and regional socio-economic conditions through architectural interventions.

Shell Game: Exploring Variation and Integration in Pre-Fabricated Facades

This research-based design studio sought to reconsider the static conformity of typical Hong Kong residential building facades that are driven largely by building code limitations, economic concerns and Fordist mass production. Students considered how building codes might be analyzed and reworked to improve performance through strategic variation. The studio brief was written to challenge standardized facades that are often repetitively applied to buildings without regard for issues like solar orientation, view or context. The studio took a more critical approach toward the overall residential tower design with a particular interest in the ‘thick’ skin of Hong Kong’s residential towers. Students made careful surveys of existing residential towers built over the course of the last three decades and traveled to the Pearl River Delta cities of Shenzhen, Dongguan and Guangzhou to visit various factories producing cladding systems and architectural interiors. The studio used the extremely dense and highly repetitive, South Horizons Housing Estate on Ap Lei Chau Island in Hong Kong as a site to test a series of new performance based, pre-fabricated façade systems.

The façade was used as starting point to rethink the entire tower typology and to generate new ideas about typical floor plan layouts, interior furnishings, structural systems and overall master planning strategies. Students looked to digital modeling software and prefabricated systems to yield not only a better performing building envelope, but one that creates a less uniform and monotonous urban environment.

Architecture & Urban Design I (ARCH 4001) – Shell Game: Exploring Variation, Integration and Coding from the Outside In

This research-based design studio has sought to develop innovations in the overall organization and design of mixed use buildings in Hong Kong.  Studio participants have reconsidered Hong Kong’s often typical approaches to programming, massing, as well as the static conformity of typical building facades, through a deeper understanding of the building code limitations, economic concerns and Ford-ist mass production that drive them.  The studio has built a critical argument toward repetitive buildings that are examples of developers’ attempts to maximize financial gain through thoughtless standardization.  Instead, the studio has combined an understanding of past and current building codes with rule-based digital tools to yield more responsive, better integrated, architectural prototypes.  As the studio name suggests, design research started with the shell or skin of the building and worked inward through various scales to rethink the overall building from periphery to plan to core.  This more critical approach toward the overall building and façade design with the use of digital software has created variations to yield not only a better performing building envelope, but an architecture that is less monotonous and more meaningful.  At the same time, the studio has also considered how Hong Kong’s building codes might be reworked to improve performance and esthetics in response to the design research.  Using digital software and contemporary computational design techniques, the studio worked to develop innovative façade systems that work within code-based limitations.  We not only considered the outward appearance of buildings, but also their performance in terms of programmatic, material and environmental factors.  The studio challenged the notion of the use of parametric or digital design tools to negotiate form or aesthetics alone.  Instead, students were asked to take a more holistic stance on digital design to consider the building aesthetics, façade performance and site specific production.

Architecture & Urban Design II (ARCH 4002) – Vertical Mumbai

This studio, run in parallel with an advanced, post-graduate studio at Columbia University’s GSAPP marks the 5th year of joint- studios between HKU and Columbia focused on the intersection of architecture and infrastructure.  The HKU studio has endeavored to use high rise development as a tool to address problems associated with rapid urban development in Mumbai.

Mumbai has a metropolitan area population of 20.5 million people and boasts the highest GDP for any city in India.  Given its large population and rapid urban growth in recent years, the city faces many challenges including inefficient transportation infrastructure, potable water shortages, seasonal flooding, insufficient open green spaces, waste management and a growing population of impoverished inhabitants.  The studio asked students to consider how high rise architecture can integrate new technologies and infrastructures to improve the social, economic and environmental ecologies of the city.

The studio capitalized on the relatively large scale and scope of contemporary development in Mumbai to embed public infrastructure into buildings (or vice versa).  Students considered how government planning agencies might incentivize private developers to combine profit-driven, luxury towers with public amenities that will benefit the overall metropolitan area.    Projects explored new models of public and private collaboration. Workshops in Rhino and Grasshopper were held in parallel with the studio.  Student teams endeavored to develop digital techniques to support their own design strategies for building massing, structure and skin.  The projects deal with integrating a range of programs and infrastructures including water purification, public space, transportation, waste management, bio-mass production and low-income housing.

Try a Little Slenderness: Explorations on the Hong Kong Pencil Tower

Hong Kong’s political system, geography and population make it one of the densest urban environments in the world. In recent years skyrocketing real estate prices fed by profit driven developers and a deluge of investment and speculation from the Chinese mainland has led to shrinking apartment sizes and more expensive real estate. Hong Kong’s pencil towers are an architectural byproduct of these extreme urban conditions.

Students in this studio studied the economic, architectural and regulatory conditions that make these extreme buildings possible to build in Hong Kong and focused specifically on residential towers with only one apartment per floor. Initial student research work included the survey and documentation of over 50 pencil towers in Hong Kong as well as research on Hong Kong’s restrictive building codes. Students were encouraged to bend the rules of the building code to create new possibilities for the world’s most slender building type.

Using digital software and physical models, the studio worked within extremely tight constraints to develop innovative structural, programmatic and circulatory strategies. The semester included workshops with real estate developers, structural engineers and local practitioners. Students worked collaboratively in teams of two on the final project to design towers sited in the Kowloon City neighborhood of Hong Kong. The resultant projects explored a range of new ideas that included mixed public/private programs, alternative siting strategies, making double use of circulation spaces, variable unit sizes and extreme structural proposals.