As the global population heads towards the eight billion mark the problems and pressure on available space are only set to get more acute. In crowded and ever-growing cities, over station developments could make a major contribution towards meeting the demand for integrated and sustainable urban communities.

Public authorities and transport agencies are under unprecedented pressure to reduce operating costs. At the same time, these bodies are also being asked to drive forward investment in modern, low-carbon and less-polluting infrastructure to cope with the extra 2.5 billion people expected to live in urban cities by 2050.

To challenge these conflicting demands, over station development (OSD) is one solution that could make better use of the space above our cities, stimulate economic growth, and reshape how cities will be organised and function for generations to come.

Building upwards

OSD is not a new concept. For both existing transport hubs and new facilities, using the station footprint to build upwards can provide solutions that address the shortage of development sites in cities. It is a logical approach – highly connected locations in prime city centre sites command high values – making the commercial case for air-rights development a sound one.

Many cities have successfully demonstrated that with the right design and technical solution, supportive urban planning policies, and the right team to deliver innovative solutions, OSDs are a viable way of creating integrated and vibrant communities.

In the UK’s capital city London, a significant commercial development opportunity has been created above the new Crossrail Station at Bond Street in Mayfair. An established example in London is the successful redevelopment of Broadgate; sitting above Liverpool Street station the site has been transformed into a mixed-use destination featuring offices, restaurants and shops.

Similarly, in Australia, key examples can be found in the delivery of Sydney Metro at Martin Place, Pitt Street and Central Station. In New Zealand, Auckland’s City Rail Link is providing substantial development opportunities across the Central Business District.

The maturity of the conversation around OSD typically relates to the level of pressure placed on the region from population growth. This maturity is only set to accelerate as younger generations seek to live and work in cities.

However, once the railway station acted simply as the terminus for commuters to alight, today they are seen as transport, commercial and social hubs, delivering footfall for shops and businesses and providing customers with convenient and accessible services.

New cultural and commercial norms

Transport authorities have become better at recognising both the risks and the opportunities that now exist in and around expanding cities. As a result, they are starting to identify and prioritise the use of low-value, high-potential space and land. Similarly, the private sector is becoming more expert at spotting the potential and making the case for exploiting it.

Increasingly, public sector transport authorities around the world are producing a reference design for development around new and existing transport hubs and investing in enabling works.

The best commercial models for these are derived from a high level of market engagement and an understanding of the needs and risks. These models result in an attractive profile for developers, while maintaining the essential core design elements in integrated place-making. As few transport authorities have either the skills or the risk appetite to take on the role of developer, this risk can be transferred to a private development partner while still retaining a proportion of any potential reward.

Understanding the benefits; managing the risks

That said, the advantages and opportunities of OSDs rarely come without huge technical challenges and therefore substantial associated costs. For both promoters and developers, a vital step is to convince potential investors that this complexity and added expense is worthwhile and a manageable risk. A long-term view of the development is essential, as is public sector investment to pump prime a model that will stand the test of time.

OSD can be complex and prohibitively expensive. Stakeholder environments and competing interests are hard to navigate, and the engineering and safety requirements of the rail sector make the design and approvals process very challenging. This is an area that very few developers really understand.

Quality design is therefore vital to manage those risks and provide successful, long-term development which creates a sense of place that reflects the needs and desires of the local community.

Executed successfully, the community stands to accrue multiple benefits, starting with improved connectivity and access to fast and efficient transit options.

Designed correctly, commuter congestion can be alleviated as over station developments act as catalysts for new and improved public spaces, residential areas, community facilities and shopping centres.

Getting on top of urban life

As global cities compete for investment under the lens of population pressure, the ability of transport hubs to address these key issues is leading to city administrators embracing OSD as a key strategic planning tool. Businesses are also pushing for better solutions to help reduce traffic and pollution effects and so attract staff through enhanced working environments. OSD can provide the sustainable transport-oriented solutions that deliver these desirable and liveable places and which address the critical social and environmental pressures now placed on cities.

Get it right and we will see OSD lead a genuine move away from the rail station being simply a final transport terminus to a destination in itself, and a hub to create new places that truly support the long-term needs of global cities.

By Grant Bowery, Director at Turner & Townsend