Affordable Housing Solution in Hung Shui Kiu, Hong Kong

Despite being one of the most vibrant economic mentroplis in the world, Hong Kong suffers from a severe affordable housing crisis due to its astronomically high property price, with the average price per square foot at HK$13,755 (US$1.8k). Subsequently, around 20% of Hong Kong's population, or over 1 million people, live in cramped, poorly conditioned housing, including subdivided homes and the infamous cage homes.

In my project, I wanted to design an affordable housing solution for the low-income community in Hung Shui Kiu, near Huen Yung Road. Hung Shui Kiu is located in the Yuen Long District of the New Territories. Experiencing rapid development from a rural residential zone to a renewed town hub, Hung Shui Kiu aims to expand its transportation system and connectivity to Shenzhen and other urban centers, reframing itself as a regional economic and civic hub. However, the rapid urbanization has displaced local villagers and traditional industries such as local markets. This has led to a call for heritage preservation and more affordable housing units for local residents.

Thus, my proposal aims to ensure Yuen Long can continue to urbanize while maintaining its cultural ties, preserving parts of its natural environment and traditional industries, and create economic opportunities and uplift the community socially. Addressing all three pillars of sustainability--environmental, economic, and social--, my affordable housing plan strives to address the following community needs:

1. Improve the environment/support local sustainability goals
2. Promote the community’s economic development
3. Preserve the community's cultural heritage

To make this a truly affordable housing project, I adapted Modular Integrated Construction (MiC) and sourced materials locally.

Ideation:

1. Sketchbook
2. Pen/pencil
3. Legos

Modeling/Rendering:

1. Revit
2. Rhino
3. Adobe Photoshop
4. Adobe Illustrator
5. PromeAi (Used Revit 3D views to create images, then imputed these views into PromeAi to create renderings, and lastly, added final touches via Adobe Photoshop)

Located in a semi-rural region, this low income apartment is within 15 minute walking distance from essential ammentities including restaurants, supermarkets, transportation, schools and green spaces (image 1). The walkability of this site and access to public transport reduces vehicle emissions and encourage daily physical activity, which contributes to the sustainability of the project (referencing the Location and Transportation section of the LEED checklist).

Inspired by the traditional Chinese courtyard residence--四合院--, I centered the apartments around a communal "courtyard" --or park (Image 6, 7). The park is permeable on all four sides, welcoming not only housing residents, but the greater public to increase the community's accessbility to green spaces. Furthermore, the pillars and archway entrances references the historical architecture of the Tang indigenous clan (image 9: Tang Ancestral Hall), reflecting the heritage of the site (image 8).

In the courtyard, residents can stroll through the park, which is planted with a variety of native plants for lower maintenance and thus higher sustainbility, exercise and practice Tai Chi, a common activity among the Cantonese elderly, and host community events such as festivals and celebrations on the staircases that double as seating on opposite sides of the courtyard.

In designing the units, I applied the concept of Hong Kong's vertical living--a city boasting over 9,000 high-rises--at a local scale: creating two story apartment units to maximize vertical space.

Building the low income units to be two stories serves not only as a poetic reference to Hong Kong's vertical living, but more importantly, it serves the practical purpose of allowing more units to fit in a single level.

In addition, this two story configuration allows the unit modules to be stacked on top of each other, creating gaps in between that creates balconies. Having two stories, with the top floor opening up to the first, also allows for better stack ventilation. A natural ventilation strategy, stack effect ventilation uses the difference in air density caused by temperature differences to circulate indoor and outdoor air, promoting a cooler indoor temperature. The less dense, warm air rises to higher openings in a building, while cooler, denser air enters from lower openings, creating a continuous airflow. This improved ventilation is escpecially essential in Hong Kong's humid and hot climate.

The apartment complex is comprised of sixteen 570 square feet units per floor, each unit housing 2-4 individuals. To blend in with the height of other apartments nearby (image 5), this apartment is 24 floors, comprising of a total of 192 units and a max occupancy of around 768 people.

The L-Shaped Form of the apartment was derived from stacking legos in different configurations to create openings for balconies yet also maximize space efficiency (image 2). By stacking modular units on top of each other, I introduce a more optimal form to fit two-story apartments in a minimal amount of space.

Each unit is only 570 square feet, which is within the range of a typical 4-person apartment in Hong Kong (between 400 and 800 square feet). On the first floor, residents can access the balcony through the sliding doors in the living room (image 1). On the second floor, there is an open kitchen and dining space. To accommodate up to 4 people, the dining area can be transformed into another "bedroom" by pulling the bed from the cabinets on the opposite wall (images 3, 4). The formal bedroom is at the end of the plan for greater privacy. Windows are installed on both walls to promote ventilation and increase natural lighting. Furthermore, the staircase not only acts as a connector between floors, but creates an opening on the second floor to allow for a high ceiling in the living room, thus improving air circulation and promoting ventilation and cooling (images 6, 7).

Using Autodesk Forma, I created an environmental analysis of the solar energy potential of the building's rooftop, and found that it can generate 117,000 kWh annually (image 7). However, since each household generates around 3600 kWh annually, or 691,200 kWh for the total 192 units, I would need to use a hybrid energy strategy to meet demand using both passive energy conservation and active energy production.

At first, I considered installing a wind energy farming on the rooftop. However, after using Forma to simulate the wind intensity in the region, I learned that wind turbines will not be effectual in this case because as the area do not experience strong winds (image 9).

Thus, I decided to integrate energy-efficient applicances in the apartments such as LED light to conserve electricity. To reduce indoor water use, the bathroom and kitchen is installed with water-efficient fixtures like low-flow faucets, toilets, and showerheads. Furthermore, since air conditioning is the major source of electricity consumption in the residential sector, accounting for around 38% of electricity used in apartments, I sought ways to reduce reliance on air conditioning through installing low energy-consumption fans, using passive ventilation systems, particularly stack ventilation (image 3), and incorporating shading devices in the top floors corridors to reduce solar heat gain. Only the top 4 floors need shading devices because, according to the Forma simulation of daylight potential of the structure, the facades lining the corridors of the lower floors receive shade for the majority of the time, so they are not subject to intense solar energy gain (image 8). Furthermore, the patterns of the shading devices references the rectangular, geometric pattern found in traditional chinese lattice doors, connecting back to the community's cultural roots (image 2). While the exterior facade of the building receives high amounts of daylight throughout the day, the balconies are "embedded" in the building, rather than being extruded from the building as with most apartment balconies. This character in itself allows the balconies to be more shaded, allowing for greater temperature comfort (Images 4, 5).

The rooftop is installed with solar panels to generate electricity and a rainwater catchment system (Image 1). The solar panels are tilted south for optimal solar energy gain as well as to facilitate the flow of rainwater into surrounding pipes, channeling them to be recycled as grey water and be used for non-potable purposes. As Hong Kong experiences frequent rains in the summer, collection gutters are placed below the solar panels to transport rainwater to the water storage tank. The tank is located on the roof to capture and filter rainwater, leveraging gravity to help pipe down water for residential use.

Due to the open core design, the corridors are also outdoors, eliminating the need to install energy-intensive HVAC air conditioning systems in the corridors found in typical apartment complexes. To ensure that the corridors are still cool, large fans are installed in the ceilings.

The central courtyard features various vegetation and shading from trees, which helps to reduce the urban heat island effect through shade and evapotranspiration. This project also incorporates Smart Growth Practices such as incorporating mixed-use development (retail on the ground floor, and residential on all other floors) and it is also strategically positioned within a 15 minute walk from essential services. (image 12)

Why MiC?

This design uses modular integrated construction to reduce building costs, expedite construction, reduce waste, and improve quality control and reliability. Since the units are produced in a controlled factory enviorment, it is not susceptible to weather elements, therefore improving the quality and durability of the material. MiC uses steel framework which could be used up to 100 times, rather than the traditional timber formwork which could only be reused less than 10 times. Additionally, MiC utilizes more precise and advanced construction techniques. Thus, this construction method can decrease on-site waste by 70%. Due to the streamlined process of modular construction, reduced chance of damage of construction materials, and how on site foundation work and in-factory modular construction can operate simultaneously, MiC can also reduce construction time by half the traditional construction time. Ultimately, the higher expediency and quality of modular construction can reduce project costs by up to 10%.

How This Project Incorporates MiC

The units are prefabricated into smaller sections according to the space usage (image 1). The MEP (Mechanical, Electrical and Plumbing) systems are also prefabricated: The raised floor system contains Electrical and Plumbing systems, and the energy systems are in the prefinished ceilings (image 5)

After prefabrication, the modules are transported by truck to the site (Image 2). They are then assembled into units on site, each unit stacking on top of each other as indicated in image 3.

Leveraging Proximity to Mainland

Leveraging Hung Shui Kiu's close proximity Shenzhen, which hosts advanced large-scale, high-precision prefab factories, the modular units can be built in the Mainland to reduce costs.

In fact, there is a current development, the Northern Metropolis Development Strategy, that aims to build a Hong Kong–Shenzhen Western Rail Link to directly connect Hung Shui Kiu to Qianhai via Shenzhen Bay Port (projected to complete by 2035) (image 4), as well as Route 11 and Northern Metropolis Highway to connect border points to Hung Shui Kiu (projected to complete by 2033). The new transportation routes would streamline the transport of the modular components from Shenzhen to Hung Shui Kiu, as the modular units can be carried via truck to the construction site, and be assembled onsite.

Examples of MiC projects in Hong Kong: (image 6) (Image 7)

Steel, concrete, and wood are used for the building structure due to their durability and ease of fabrication. Concrete, in particular, is preferable due to its ability to withstand Hong Kong's humid climate. Although concrete may be notoriously known as an unsustainble material due to its high embodied carbon content, using modular construction will actually reduce the carbon creating of the concrete structure. This is because in the controlled factory environments, less waste is produced when creating precast concrete. Additionally, the factory can easily recycle waste material compared to traditional on-site pouring. Furthermore, precast concrete decreases the need for operations like mixing and curing used in on-site pouring, thus minimizing on-site CO2 emissions. The materials and production of the prefabricated modules is within a 500-mile (800 km) radius of the project site, rendering the transportation of the units more sustainble by reducing fuel consumption and thus carbon emissions due to shorter transportation distances.

For shading devices and finishes, bamboo is used because it is a fast growing and highly renewable material endemic to Asian countires. Often seen in Hong Kong construction scaffolding, this material can be repurposed into the shading devices and other decorative features such as handrails (image 5).

The demolition stage of a building is often overlooked and underhighlighted when designing a building. Despite the goal to have the building to last as long as possible, it is inevitable that a building will reach its end of its lifespan, so I wanted to ensure that its deconstruction is considered in the greater sustainability goals of this apartment complex. To ensure the sustainability of this structure during demolition, these construction methods will be adapted:

1. Avoid using sealant or glue for construction, relying on nails, bolts and screws instead for easier disassembly
2. Since intertwining electrical, plumbing, and HVAC systems could complicate diassembly and prevent flexbility in altering or removing a system, MEP systems would be seperated to enable easier recycling during demolition
3. Using standard materials such as concrete, steel and wood, and avoid composite materials so that materials can be easily reused, or recycled
4. Having uniform materials and simple designs to allow for easy sorting

The material waste can be sorted in Tuen Mun Area 38, which is 15 km from the site, into inert (stable materials like concrete) and non-inert waste (decomposable materials like wood). While the non-inert materials can be disposed of in landfills, inert materials can then be reused in future construction projects, thus alleviating landfill burden.

The communal courtyard park invites a diverse range of activities (Tai Chi, Go, a chinese board game, Ping Pong, etc), and is open to the public to benefit the wider community. The landscaping consists of mainly native plants to reduce maintenance, enhance biodiveristy, and decrease outdoor water use and other resource use, thus increasing the sustainability of the park (image 3). The two staircases which double as seating can be transformed into a space to host festivals and various community events. To promote economic development, the ground floor hosts retail stores, welcoming both traditional and modern businesses.

Using the LEED scorecard, based on my existing sustainble strategies, the project receives a LEED Silver certification. This is achieved through the incorporation of green spaces, promoting walkability, using renewable energy sources, implementing passive energy systems, encouraging daylighting, improving water efficiency and management, and considering the life cycle of materials from construction to demolition.

Since in-factory prefabrication of units and on-site excavation and foundation work can occur simultaneously, this project takes significantly shorter time to complete compared to traditional residential buildings. It is estimated that this project will take around 12 months to complete.

I created my base models using revit, then used adobe photoshop to create the technical drawings. For renderings, I used PromeAi to create a base rendering, then fine tuned it using adobe photoshop. I also used Autodesk Forma to create enviornmental analysis to inform what sustainable strategies would be most effective for my site.

Before designing my project, I conducted extensive research on existing MiC projects in Hong Kong, Tokyo and Montreal: Innocell (Image 3), Nakagin Capsule Home (image 2) and Habitat 67 (image 1).

All of these projects utilized modular pods/capsules that could be rearranged and stacked, inspiring me to use legos to brainstorm possible design configurations. Habitat 67's stacked concrete modules creates unique terrains and outdoor spaces. This idea inspired me to stack the modules in a way to similarly create outdoor spaces such as balconies.

Nakagin Capsule Home's concept of plugging in modules inspired me to overlap units like a Jenga tower, while InnoCell's highly efficient construction process, completed in only 14 months (which was 6 months ahead of schedule), led me to research more thoroughly how modular integrated construction can save time as well as reduce material waste and cost less.

Through this project, I was not only able to improve on my Revit modeling skills and Photoshop skills, but also learned to use a new software, Autodesk Forma. In addition to furthering my technical skills, I was able to deepen my understanding in modular construction and how it can create more sustainble buildings. Reseraching the site and current developments in the area also reminded me of the need to always consider the community I am designing for, and be aware of its challenges as well as its aspirations.

Although this was an incredibly challenging project, it was also extremely rewarding as I was able to gain a deeper understanding of the architecture and construction industries. I am deeply grateful to Autodesk and Instructables for this opportunity to exercise my creativity and problem solving skills within real world constraints, and supporting my passion for architecture.