Engineering has always been about building for what lies ahead—creating lasting legacies in the form of extraordinary buildings or resilient infrastructure that can stand for centuries. David Symons, sustainability director for Canadian engineering firm WSP, looks at some of the ways the profession is designing now to be ready for the future.

Now more than ever we need to adopt a future-ready approach to design that anticipates developing trends in climate, society, technology and resources. And although we can’t see precisely into the future, we can build schemes that will be adaptable to suit our changing needs.

We are asking engineers to think about ways to support the hotter, windier, wetter cities that are predicted for decades hence. And that can involve a mind-boggling range of solutions to meet—for instance, the demands set in UN Sustainable Goal 11 focusing on rapid urbanisation.

The United Nations predicts that more than half of humanity, around 5 billion people, will be living in cities by 2030. By 2050 this number will reach over 6 billion. In 2019 cities house 3.5 billion people and occupy just 3% of the Earth’s land but account for 60% to 80% of energy consumption and 75% of carbon emissions. What can engineers do to create places that are safe, comfortable and healthy to live in long into the future?

Is your business looking for ideas on making a positive environmental impact? Check this free online report from B Lab that compiles articles and resources to help your business become a climate leader. Whether you work at a large company or an agency, get inspired to do more today.

Options can include creating space without encouraging urban sprawl by building upward and—more challengingly—downward, and planning everything with a fundamental switch to electrical power in mind to reduce carbon emissions.

Solutions don’t necessarily have to be expensive, but they do require engineers to build in flexibility upfront and to explain that need to their clients. Engineers are by definition problem-solvers, and we are challenging them to be at the heart of solving the big issues of the future. We are giving them the chance to create something compelling and exciting that will be around for hundreds of years. Future-ready really is at the leading edge of intelligent engineering.

Let’s look in detail at just one aspect: How you can create extra space in densely developed cities.

Taking Urban Development Underground

Cities are gaining 77 million new residents each year, equivalent to the population of Turkey or Germany and twice that of California. Over the first three decades of this century, the global increase in land cover is expected to be greater than all urban expansion so far in human history. Urban centres ranging in size from 500,000 to 10 million residents will continue to evolve, putting land in these high-density areas at a premium.

Underground construction is creating sustainable opportunities and approaches to address those realities. And there is a growing recognition that the future should include integrated cities where underground facilities link with infrastructure and make life above ground more enjoyable.

I’d argue that we must start planning for the underground city now.

Of course, this is not a new concept. In the early 1960s, Montreal embarked on a visionary project designed to cover exposed railway tracks connected to the Central Station in the heart of downtown. The initial development connected an office tower, an underground shopping mall, a major hotel and the station via a pedestrian tunnel system. This has since developed into a network spanning 33 kilometres that is used by as many as 500,000 people and contains bus terminals, business, housing, restaurants, parking, university pavilions and much more.

Sixty years later, there are a growing number of schemes around the world that include plans below the pavement.

For example, in north-central Paris an abandoned underground parking garage below a 300-unit affordable housing complex has become the La Caverne subterranean farm — 3,500 square metres of underground permaculture that produces 54 tonnes of vegetables and mushrooms annually.

And in March, Singapore’s Urban Redevelopment Authority unveiled its 2019 draft masterplan proposals for an inclusive, sustainable and resilient city that included designating three areas to develop underground. The strategy intends to free up surface land for people-centric uses by relocating utilities, transport, storage and industrial facilities underground.

At WSP we are engaged in future-ready underground infrastructure around the world.

In Sweden we are involved in redeveloping the Slussen Bus Terminal in central Stockholm into an underground transport hub linking commuters with buses, trains and metro lines. With surface space at a premium, the decision was made to excavate more than 250,000 square metres of rock to create caverns to house the new underground terminal. When the work is complete in 2023, surface space will be freed up for redevelopment as part of a dynamic new urban quarter.

And in Mexico, Garden Santa Fe in Mexico City is an above-ground park complete with a running track and terrace that surrounds a seven-level underground shopping centre housing retail stores, entertainment, a food court and three levels of parking. Central to the scheme are three inverted glass cones that project natural light and ventilation into the mall.

For more information on what is going on with underground construction worldwide, download the WSP report Taking Urban Development Underground.

Creating Space Out of Thin Air

That’s down, but what about up? Cities have been building skyscrapers for a long time, but finding land for them as development becomes denser and pricier in cities will be a future challenge.

But with clever engineering, space can be conjured out of thin air. At Principal Tower in London we have helped create a new 50-story mixed-use development in the air above railway lines but so discreetly that residents never know that trains are running beneath the buildings.

Buildings have been erected over railways before, but the really tricky part for us was that almost half of the Principal Tower’s foundation had to leave space beneath in a protected corridor for potential tracks in and out of Liverpool Street station — known as the eight-track corridor. At the same time the architect did not want the conventional, visible, massive arches or A frames that are the usual options for bridging rail lines, so a primary objective was to develop a design that looked like it was built on solid ground. Our solution had to be a hidden gem.

We devised a design that involved forming the sides of the protected rail corridor, effectively creating a tunnel.

Principal Tower has been a showcase of what is possible with precision engineering in the empty space over railway lines. And the possibilities of that space have been the subject of research at WSP to tease out the full potential of creating space for infrastructure to address London’s housing crisis.

In our study Out of Thin Air, we analysed London’s rail infrastructure and concluded that development of its most viable “overbuild” sites could potentially provide the city with more than 250,000 new homes — or several years’ housing supply. A follow-up report, Out of Thin Air One Year On, aimed to identify the best sites and in doing that found that more than 280,000 new homes are possible at rail overbuild sites.

The benefits of the approach are many. Clearly no new land or major demolition is required. But more importantly, the developments would offer a sustainable solution to urban development. They would give residents greater mobility, placing them closer to rail or metro stations while promoting the ridership of public transport, cutting car use and helping to reduce emissions and improve air quality.

The methodology we used to gauge overbuild potential can equally be employed to identify similar opportunities in any dense, space-constrained city anywhere in the world. Applying an informed estimate of 1,200 homes per hectare on rail land indicates that Melbourne, Australia, could create around 77,000 new homes within 10 kilometres of its centre, while Vancouver, Canada, could build 46,000 hew homes. In Copenhagen, the potential is almost 42,000 homes.

By taking a global perspective, engineers are able to draw on best practices from all over the world as they look to tailor solutions for specific circumstances such as growing populations. Future-ready is at the leading edge of intelligent engineering and will have a positive impact as this century unfolds.

The Energy Challenge

The “electrification of everything” is designed to reduce emissions of greenhouse gases and its effect will be largely felt in cities, which account for about 70% of carbon dioxide emissions. The transition to electricity will be one of the defining features of the cities of the future.

We are designing schemes in anticipation of an electric lifestyle. In Bermondsey, London, a Grosvenor Estates proposal for 1,600 residential units and 14,800 square metres of flexible commercial space is designed with the idea that cars, heating and day-to-day life will be powered by electricity. We looked at how vehicle patterns mean that residents will move away from car ownership toward pool vehicles, with car club vehicles to be provided on site and facilities put in place in anticipation that many of these will be electric vehicles.

To cope with rising demand for energy, cities are developing innovative strategies to generate, distribute and consume energy as cleanly and efficiently as possible while addressing issues of reliability and security. One such strategy involves the use of microgrids and distributed energy systems.

These represent the next stage in the push toward electrification—a way to reach into the far corners where the big grids cannot go and to make electric service more reliable, clean and less costly.

Most will be located close to a point of consumption, generally in an area with a defined boundary such as a residential district, a university or corporate campus. Microgrids help reduce the cost and potential energy loss involved in transmitting electricity over long distances, support energy reliability because they can disconnect from the grid and operate in “islanded” mode under emergency conditions, and contribute to sustainability goals by incorporating renewable energy sources.

As an example, in Quebec, Canada, Hydro-Quebec is developing a microgrid in Lac-Megantic as a way of testing new technology with the goal of rolling it out elsewhere. Being planned with our assistance, the project calls for the installation of solar panels on 30 residential and commercial buildings with a total of 300 kW installed capacity, 300 kWh of battery storage and electric vehicle charging stations.

Around the world, engineers have signed up to the UN sustainability goals and are developing ways to meet the ambitions. What is clear to us, and should be for everyone involved in infrastructure, is that for future goals to be achieved, the hard work starts now.