a plane of reference
Gaochun is one of seven districts of the provincial capital Nanjing. Although situated 70 km south of the capital, the new freeway and light rail are enabling stronger ties and are fueling rapid growth. This 5sqkm urban expansion is one of Nanjing’s twenty planned Technology and Science Community (TSC) districts, or technopolises. Its innovation potential is strengthened by its proximity to the adjacent industrial district and to a planned university campus to the east of the site. Being situated along the northern edge of Gu Cheng Lake makes it an ideal location for more than just hi-tech work places – this is a place for a complex and rich but specialized city.
The first design decision was the preservation of the largest village on the site; maintaining the smaller settlements was not an option for the client. While this maintains some historical reference in the new city it also offers an urban spatial texture not provided by the demands of the contemporary city.
Water networks on the site were preserved and the larger wetlands maintained. These combine with additional green links to form a continuous park network within a 5 minute walk (400m) of all parts of the site.
public transport scale (TOD – LTA)
The site was then divided into five local transport areas (LTAs), approximately 800m x 800m. Public Transport (PT) routes were then centred in the LTAs, ensuring a 5 minute walk to public transport within each LTA. The future metro runs through part of the site touching the main PT east–west spine, with a metro station positioned at the centre of one of the LTAs.
The LTAs are made up of four neighbourhoods (approximately 400m x 400m), and each neighbourhood is made up of four mosaics of sub-culture (200m x 200m). This community structure provides a rich and complex set of city scales that provide a sense of place and a sense of belonging to the community.
hierarchy of roads
The highest traffic volume roads have been situated at the perimeter of each LTA to remove the need for people to cross major roads in their daily life. Central to each LTA is the commercial network which is attached to public transport. Other roads are designed as green quiet streets for living and or working.
Like water rippling in a pond, one set of streets run parallel to the lake edge. The other set of streets run perpendicular to these avenues and produces a legible street morphology, with most of the perpendicular streets having a water view. A block size of between two and four hectares was selected in an attempt to balance market demands with urban design ideals. The market’s ideal is mega blocks to maximize development area. The urban design ideal is a smaller block providing a permeable (walkable) city with and even distribution of road traffic loads, an increase of building perimeters along streets, and an expansion of the public realm.
integrated land-use and networks zoning
To achieve a fine grained distribution of living and working programs across the site a continuous network of each program has been developed. The areas where these living and working land-use zones overlap one another are zoned hybrid (living-working) zones, maintaining a degree of flexibility to absorb the variance in demand caused by a cyclical development market. While hybrid land can be utilized as either living or working according to market demand, a minimum amount of each is maintained.
The commercial and retail network is situated along either side of the public transport network. As the city matures, its local retail, entertainment and support services will be free to emerge along these routes bringing these programs within a convenient 5 minute walk to all residents of the city.
no undies hanging on main street
The east-west spine is seen as the public face of the district and is zoned for predominantly office and laboratory functions with service oriented street edges.
public open space – a fractal distribution
Each scale of community structure (LTA, neighbourhood, and mosaic of sub-culture) is provided with a park and a plaza. This develops into a system of fractal public open space distributed throughout the entire city. All these spaces are linked by the green street network.
Public programs have been distributed across the site according to population density, walking distance and access to public transit and parks. Vegetable markets, supermarkets, hospitals, sports centers, community centres, schools and kindergartens are attached to the fractal open spaces.
city form + sunny active edges
Height controls are driven by the need to protect solar access to the commercial network’s active street edges during winter lunchtime hours. These height controls also protect public open spaces, including the fractal open space network, from excessive overshadowing.
The networks of land use extend to the waterfront, bringing a diverse array of both ecological and urban areas, passive and active uses, and business and mixed residential programs to the water’s edge, piers and jetties. A necklace of public buildings take prime locations along this foreshore.
environmentally sustainable design – esd
Urban scale initiatives include a city scale sustainable urban drainage network, based primarily in the green network. A reduced dependence on travel and travel in private vehicles is enabled by the integrated live-work zoning and by the convenient distance (max 400m) to public transit. A combined services duct running along the central spine of the city and branching out to various extremities provides for ease of monitoring and future proofing for smart green technologies. A central green services plant for combined heat and power CHP plant is proposed for each of the LTAs.