Keith Griffiths is chairman of architectural firm Aedas. He discusses the advantages of an elevated network of bridges in residential complexes. What are the advantages of elevated interconnected pedestrian walkways? During the planning and architectural design stage, what factors have to be taken into account? Hong Kong and [mainland] Chinese cities are dense urban environments where pedestrian movement at ground level is compromised. Our pavements are insufficiently wide for the people they need to serve and they are located alongside busy roadways that are dangerous to cross. Our cities need two further pedestrian networks: above and below the interruption, noise and pollution of busy roads. Asian cities are developing subterranean pedestrian networks linked to extensive subway systems and to building basements, as well as elevated pedestrian networks linking the second floors of buildings. These three pedestrian network systems will create safe and convenient links between our buildings and through our cities. The roads, pavements, subways, concourses, underpasses, bridges and building connections of interconnected cities must provide convenient and safe passage for cars, bikes and pedestrians. Through this holistic planning we are able to optimise the land use and convenience of travel by foot or by transport system across cities. Our government departments of Building Control, Lands, Planning, Highways and Transport must work together to create a plan for our city which includes a high level footbridge system. What are the economic, technical and social problems/constraints associated with the planning and construction of skywalks, especially interconnecting buildings, old and new? The economic, safety, health and convenience benefits of skywalks far exceed the minor issues associated with their planning, construction, maintenance and any perceived social [issues]. The Mid-Levels escalator is an example of a skywalk, which abuts directly onto existing second- and third-floor residential buildings, but no one would deny the economic benefit that the escalator system brought to this rundown area. The tenants realised huge increases in the values of their properties and moved to better residential buildings to make way for a vibrant and well-connected new commercial part of the city. For footbridge networks to become established, it is necessary for the government to draw up a cohesive city plan which identifies where the footbridge system is to be built. Private developers and building owners can then participate safely and without risk in constructing the system to the approved plans. Do you think building a multilevel elevated system is feasible? Is it a solution to high-density living? Hong Kong’s elevated walkway system already extends to the first and third floors such as in the Mid-Levels escalator and Hong Kong Central footbridges. The network includes elevated parks such as The Forum at Exchange Square and ICC. Our future cities will be more dense, complex and interconnected. The lower levels of buildings will be more open to public use with wider public passage as people increasingly use public transport and walk to work. Buildings will become porous to allow the public to access into and through them. I envisage a future of elevated public parks and decks connected by multiple level elevated walkways. These walkways will bring improved commercial value to the lower levels of buildings. Apart from serving as a footbridge, are there more purposes our skywalk system can serve? Can more entertaining facilities, greening and open space be created out of it? I believe that future cities will no longer have inhospitable pavements alongside impenetrable towers. The lower four or five levels of our future city will be a porous series of interconnected decks, skyparks, bridges, retail, dining, entertainment and public facilities. These well planned and well lit spaces will give access to the towers above and to the subways and basements beneath. The public will be able to walk across huge sections of the city without ever touching the ground or interfacing with roads and traffic. Alfresco dining will spill out onto the walkways and terraces; office lobbies and shop frontages will access directly onto these upper levels. The extensive greening of these sky terraces will provide clean air, breezes, sun and connectivity to nature.