With condo towers being erected in cities around the world, cities are experiencing unprecedented growth and development. The densification of cities is putting more pressure and demand on transit systems, infrastructure, utilities and environment.
The impacts of each new development can have wide-ranging effects. Researchers at the University of Toronto are working to better understand, and in turn inform, the impacts of each decision to ensure that our cities are built to last, are cost-effective, and limit the strain on our natural resources and the environment.
Meet five professors who are better informing the debates about how our cities carry on with daily operations.
Professor Heather MacLean – Buildings and Energy
Professor Heather MacLean develops and applies systems-level approaches to quantify and evaluate the environmental and economic impacts of different engineering projects and processes. She has examined the life 
cycle energy use and greenhouse gas emissions associated with urban and suburban developments, including the production of building materials for housing and energy required for transportation. Currently, her research is focused on determining the environmental and economic implications, from a life cycle perspective, of a large set of conventional and alternative fuel and vehicle options for personal and freight transportation.
Understanding the systems level and life-cycle environmental and economic implications of different development scenarios is critical to inform a variety of stakeholders from policy makers to contractors and consumers, who all play a vital role in making our cities more sustainable.
It’s important to focus research on cities because of increasing levels of urbanization. About half of the world’s population lives in cities, which has a few effects. First, cities are playing an increasingly important role in the global economy because of the large populations who live in them. Second, there is an increased awareness of the fact that cities are large contributors to greenhouse gas emissions. Third, it is predicted over the next 30 years, almost all population growth in the world will be in cities in developing countries. Particularly in these emerging nations, where many more cities are expected to become megacities (cities with a population of over 10 million), there is an opportunity to inform more sustainable outcomes for these cities through appropriate planning and using an evidence-based approach. Hopefully, this can avoid many of the errors we have made in the planning and development of cities in mature economies.
Future levels of urbanization are expected to be even higher than they are now. Even at current levels many cities are struggling to provide adequate services and infrastructure for their residents and maintenance is severely lagging in many developed and developing regions.
There are a number of trends that coincide with this increase in urbanization. Some sustainable trends include an increased focus on developing walkable neighbourhoods, promotion of active modes of transport, car sharing, expansion of public transport options, and increased attention to energy efficiency in buildings. However, there are other trends that cities must also come to terms with including a desire for larger homes, consumerism and the ‘throw-away’ nature of many products. If there isn’t due attention paid to these trends, cities will need to respond to the many negative economic and environmental impacts.
Professor Matt Roorda – Transportation and Logistics
Professor Matt Roorda and his team at the University of Toronto research freight transportation and logistics, and curbside management in urban areas. They investigate better methods to optimize freight systems to improve their efficiency, taking advantage of new technologies (e.g. automated vehicles, drones, electric bicycles), and innovative new processes. They also develop city-wide models of freight transportation to predict the impact of freight on congestion, emissions and safety. This is important in a time where delivery of items is becoming increasingly complicated due to space and traffic constraints.
These constraints present specific challenges that Roorda and his team are looking to solve. Congestion, in particular, is a topic receiving a lot of attention because people living in cities deal with it everyday. This is true for both public transit and roadways. Infrastructure designed to relieve the pressures of congestion is needed. However, infrastructure projects are expensive and prone to extensive public debate. Roorda and his team are working to add evidence and fact-based analysis to inform decisionmakers when considering transportation infrastructure.
Another challenge for cities is to make better use of urban spaces. Urban areas have the potential to be more sustainable than sprawling suburbs. Cities must approach space allocation n new ways for urbanization to be successful. The curbside management research done by Roorda’s team focuses on ways to use street spaces more efficiently for transportation, delivery services, and make them great places to walk and cycle.
Roorda points to Peel Region as a municipality applying his research well. Peel is a freight hub in Canada. It has a very large distribution centres serving all of Toronto, southern Ontario and beyond. Roorda’s team has worked closely with Peel Region on pilot projects, including one that focuses on making deliveries in off-peak times.
Roorda thinks that one of the biggest questions in the coming years will be the introduction of vehicle automation. This technology could be beneficial if these vehicles can increase capacity, improve safety, reduce emissions (if they are electrified), and improve mobility for elderly and disabled. Alternatively, this could increase congestion and increase the number and length of vehicle trips.
Professor Marianne Touchie – Buildings and Energy
Assistant Professor Marianne Touchie is researching ways to improve the quality of indoor environments while also reducing building energy use. She specifically focuses on aging high-rise multi-family housing in cities. Using the Building Energy and Indoor Environment Lab, Touchie conducts primarily field-based research, examining the performance of existing buildings through monitoring and occupant surveys, and attempting to determine potential operational or retrofit strategies to improve performance.
Touchie hopes the lessons learned in the field, and the solutions modelled and tested in the lab and the field, can be integrated into policies and programs to influence the design of future cities. An example of this is a current study testing new control strategies for smart thermostats to reduce energy use in new condos, while achieving thermal comfort for occupants. The study involves several user groups, including local utility companies hoping to integrate findings into their energy-conservation programs.
In an effort to meet 2050 greenhouse gas emissions reduction targets, cities need to do more than just halt construction on new buildings. They would need to reduce energy use in existing structures. Around half of emissions in cities are a result of building operation, meaning significant energy retrofits are needed before 2050 to meet our goals. Furthermore, any new buildings must not contribute to the environmental burden and, if possible, should produce more energy than it uses.
In Europe, cities have benefitted from a stringent energy policy regime, but also a very important and differentiating factor – substantially higher energy prices. The argument, however, needs to be framed differently to be effective in Canada. It needs to be conveyed that low energy buildings are usually more comfortable, durable, and resilient to changing weather conditions. Beyond pushing for small energy cost savings, cities should also be demonstrating the broader benefits of higher performance buildings to both occupants and owners.
One of the most concerning trends Touchie identifies is increased use of air conditioning, since it uses a lot of energy to compensate for poor building and envelope design, particularly in contemporary glass buildings. Glass buildings are energy intensive, but also uncomfortable for occupants who experience a wide range of thermal and visual comfort issues. In recent years, restrictions have been placed on the proportion of glazing allowed in buildings, but this is only a start. The goal should be to find ways to allow our buildings to be operated more sustainably.
Professor Paul Gauvreau – Structures and Bridges
Professor Paul Gauvreau researches new designs for structures and bridges – an often overlooked aspect of city infrastructure. Bridges tend to be an afterthought, serving primarily a functional purpose, unless they’re not. He defines two different types of bridges; premium bridges on which money is spent for aesthetic purposes, and practical bridges for which no aesthetic premium was paid. Focusing on the latter, Gauvreau believes these can be done better and be made more aesthetically pleasing than they currently are.
Particularly in cities, the focus tends to be on building premium bridges. The Champlain Bridge in Montreal (expected cost of $4 billion) is an example of how much a premium bridge can cost. Several design features of the bridge offer nothing in the way of functionality, so it can be assumed these features are purely aesthetic. Common estimates for aesthetic premiums paid for bridges fluctuate between one to 10 per cent. Conservatively, the aesthetic premium on the Champlain Bridge is estimated at $40 million.
Beautiful bridges can be built without paying a premium. “Bridges don’t need to be extravagant to be aesthetically pleasing,” says Gauvreau. “There is a perception that if a lot of money is spent, it leads to a beautiful bridge, while spending less leads to an uglier one. This is not the case. Practical bridges doing their job well have the potential to be beautiful.”
It comes back to the debate over whether the aesthetics of bridges should be publicly financed. Practical bridges can be constructed to look better by innovating our designs and approaches, without paying a premium. There are plenty of opportunities to build with new materials or to build with new combinations of existing materials.
Bridges are a necessary part of the infrastructure of many cities and they impact city life in several ways, which can be improved. First, the value/cost paradigm needs to be re-evaluated. Bridges have the potential to be built for lower capital cost. By adopting newer ideas and materials, it’s possible to do things more cheaply and more efficiently. Second, disruption during construction must be limited. This is especially true in densely populated cities, where infrastructure projects inconvenience many. Third, bridges can be used to create a better visible environment. Bridges are permanent and visible on a daily basis. Their permanence makes it essential that they are made to look as pleasing as possible. A poorly designed bridge can affect a region’s mood or emotion for decades.
Professor Shoshanna Saxe
As cities continue to grow in size and importance, so does the need for them to be sustainable. Sustainability can mean a lot of things, but Assistant Professor Shoshanna Saxe is interested in understanding and improving the planning, design and construction of urban infrastructure. 
“There is an intimate relationship between the things we build and the world we live in,” says Saxe. “When we build a specific type of infrastructure, it changes how we live. If we continue to build roads, this incentivizes people to drive more, creating more traffic and emissions. If we invest instead in transit systems and supporting density, we have better accessibility for more people.”
Her central research question is ultimately, how do we make decisions around what we build to get to the society we’re trying to achieve? The research focuses on understanding the relationship between urban infrastructure and societal scale sustainability goals, taking into account design, construction, operation, use, and policy.
“I often get asked the wrong question, ‘what kind of infrastructure should we be investing in?’ So my answer is always ‘yes’. Yes we should be building all of them where they’re appropriate. Context matters,” says Saxe. “We need to be building the type of infrastructure that will support population growth of cities in a sustainable manner.”
Saxe would like her research and work to move the needle towards building more ambitious civil infrastructure to support vibrant and sustainable cities. Two conditions must be met for cities and urbanization to be sustainable. First, the transport infrastructure being built must be the right kind, and second, cities must be effectively layering land use and infrastructure planning . Her research works to discern the best possible infrastructure planning and construction for sustainable cities.
There is no specific city that gets the infrastructure question perfectly correct, however many are doing well in specific aspects. The U.K. is publicly engaging with the question of which infrastructure to build and where. Los Angeles, due to it having a high vehicle-per-capita ratio, is making massive investments in transit. Vancouver and Montreal are both investing in bike lanes. In Copenhagen, more than half of daily trips made by residents are made on bikes.
The movement towards deliberate planning in cities is a trend Saxe welcomes and she hopes continues. Ideally, more energy will be put into working to improve cities for the future. She also noted one harmful trend in particular; the tendency to think that ‘newer is better’ when it comes to ideas about cities. There is a lot of pre-existing knowledge in this space that should be drawn upon.