Building smart, safe and sustainable cities

For the first time in human history, more than half the world’s population — about 3.9 billion people — live in cities. By 2050, the UN estimates that number will climb to 66 per cent.

“Urban populations are increasing at a pace that far outstrips the ability of governments to provide services,” says Jyoti Gondek, director of the Westman Centre for Real Estate Studies at the Haskayne School of Business. “This requires revisiting concepts like corporate social responsibility, stakeholder engagement and government accountability to ensure we find solutions.”

It also requires technical solutions to reduce and manage waste, harness clean energy and address our security in public spaces and in our homes.

Building deconstruction: demolishing demolition

When you want to build a new house or other structure, generally you tear down the old one and all the building materials — every two-by- four, scrap of drywall and kitchen sink — is carted off to the landfill.

A house is made of a variety of materials, some of those can be recycled or diverted from the landfill and some cannot."

“It’s a big problem precisely because it’s such a small problem,” says Josh Taron, associate professor of architecture in UCalgary's Faculty of Environmental Design. “Demolition cost is one of the smallest costs for any individual project. However, when you start to add up all these individual projects, all of a sudden, you have a very big problem for cities.”
 

As much as 20 per cent of municipal landfills are full of construction and demolition waste — millions of tonnes. Taron is studying what’s in that waste. Working with the City of Calgary, architects, owners and demolition contractors, Taron studied a group of 15 houses that were scheduled for demolition to quantify the waste produced.

“Is there a difference between waste from a house that was built in 1910 versus a house that was built in 1950 or 1990?” he says. “A house is made of a variety of materials, some of those can be recycled or diverted from the landfill and some cannot. But how do you actually keep track of those things? How do you start to understand them?”

Taron is working on a model for quantifying demolition waste. By knowing what sort of waste and how much a given building might produce, municipalities will be better able to plan for the future. “By identifying buildings that are about to become waste, cities can take proactive measures to mitigate those effects,” he explains. 

Taron is also studying how to construct houses and other buildings so they can be taken apart and their components reused instead of being sent to the landfill. Right now, it’s expensive and labour-intensive to dismantle existing houses. “When owners make a decision whether to demolish or deconstruct, the easier and more certain decision is to demolish,” he says.

Buildings don’t come apart as easily as they go up. “There are lots of permanent fasteners like nails and screws and glue,” says Taron. “If you think you have a recyclable material like wood but it’s connected to other materials that are not recyclable, everything ends up going into the landfill.”

Prefabricated houses might make deconstruction and reuse more accessible and cost-effective. “Building in chunks minimizes onsite labour and construction times,” he says. “From a design perspective, it’s interesting to think about what kind of new forms are out there that are more sustainable, more affordable and actually enhance building performance.”

Turning trash into treasure

A full-scale pilot project and research facility in Calgary is testing technology that could turn piles of garbage in landfills into piles of resources that can be composted, recycled or used as fuel.

“People think waste is a liability, but we can use the waste as a resource,” explains Dr, Patrick Hettiaratchi, PhD, professor of environmental engineering at the Schulich School of Engineering, who is partnering with the City in the Calgary Landfill Bio-Cell (LBC).

The facility has 85,000 tonnes of residential and commercial organic waste. “First, we create an anaerobic bioreactor by recirculating leachate, a liquid, to enhance the production of gas in the landfill,” he explains. “Then we inject air into the solid waste to create an aerobic bioreactor. Finally, we mine the Biocell to recover both material and space.”

“People think waste is a liability, but we can use the waste as a resource."

That mining uses a number of different technologies that separate recyclable materials, compost or refuse derived fuel (RDF). The Biocell also employs thin biocovers that help oxidize methane, making it a "zero-methane" emission landfill.

“We’re measuring a number of factors in the Biocell ,” says Hettiaratchi, "including internal temperatures, how the landfill has settled at different heights as well as landfill gas flow rates. That data is letting us map out internal gas distribution to make sure we’re on track with creating a sustainable landfill.”  

The landfill has come a long way from the days of just dumping solid waste and leaving it. The next wave of landfills used bioreactors to create a liquid that circulates through the waste to help it settle, break down and degrade. The Biocell goes further and promotes sustainable solid waste management.

The award-winning Biocell project is both simple and cost-effective. “We combine everything in one facility — solid waste and compost,” says Hettiaratchi. “That way we don’t need outside energy, we create our own, and we don’t throw out anything.” 

Catching rays in the city

The more people who live in an inner-city neighbourhood, the harder it can be to find good places to place the technology to harness the energy of the sun. Tall buildings throw shade on smaller ones. Bridges, trees and construction can also block access to the sun and its clean energy.

“They allow buildings to generate renewable energy."

Dr. Caroline Hachem-Vermette, PhD, is working toward solutions to increase the potential of solar capture in high-density urban areas.  The assistant professor of building technologies in the Solar Energy and Community design lab at the Faculty of Environmental Design (architecture) is developing guidelines for mixed-use solar communities, combining energy efficiency measures with solar technologies.

Hachem-Vermette is working on transforming existing multi-story structures, like apartment buildings, into high-performance, green-energy generator buildings by designing efficient façade systems that can accommodate solar technologies.  

“When it comes to achieving net zero energy status in urban areas, multi-story buildings present a challenge,” she says. “Their building envelope, especially façades, are not quite energy-efficient, while the space to accommodate solar technologies is limited.” New façade systems include curtain walls and double-skin façades that can be applied to existing or new buildings, to integrate solar capture technologies such as solar photovoltaic systems, advanced windows and shading controls.

These façade systems are designed with specific tilt and orientation angles, maximized surface areas and solar energy collectors, and have the potential to increase the energy generated by up to 250 per cent.  “They allow buildings to generate renewable energy which reduces the reliance on fossil fuels and lowers greenhouse gas emissions,” says Hachem-Vermette.

“We can apply these curtain wall systems to all types of buildings under different climate conditions, with some specific modifications,” says Hachem-Vermette. “We’re looking at the geometry of the building envelope, insulation, airtightness, the type of glazing and surface areas. These are all components that determine a building's ability to integrate solar technologies and in turn increase its energy performance.”

Reading biometrics to keep us safe

We're used to seeing biometric information, from fingerprints to retina scans, in Hollywood movies about complicated bank heists. Biometric controls for safety and security will soon be more apparent here in real life at events, transportation hubs and airports in cities around the world.

"Someone's document may be fine, but if something doesn't match, say their face or their gait, it means the smart access system would alert the personnel at the security check up," explains Svetlana Yanushkevich, professor in Electrical and Computer Engineering at the Schulich School of Engineering.  "Then the security personnel can attend to the high-risk alerts while low-risk people can be processed very efficiently."

Biometric information can do more than reduce bottlenecks at airport security lineups. Yanushkevich and her students are testing how to use technology to accurately read pain on a person's face in order to help the elderly and immobile.

"Say the elderly patients are bedridden and could be in pain but cannot communicate," explains    Yanushkevich. "The sensors will monitor their face to register the pain level and then send textual information, such as 'Alert in room 25: This person seems to be in pain.'"

Researchers are sorting out technical issues, and there are ethical and privacy concerns as well. "We have to make sure that the procedure and technology are compliant with consents that the patients or their guardians sign," says Yanushkevich. "Privacy versus security is a huge subject."

Eventually, biometric information may be used to help create smart senior residences and support the people who live and work there. "We don't replace personnel," she says. "We are assisting them to make better use of their resources by getting more information."

Building safer, healthier cities

Most North Americans grew up around cars. One in the driveway, maybe one in the garage and certainly lots of them on our streets. As cities grew, we tried to accommodate those cars by building more and wider roads. Over the decades, we developed cities that are dependent on cars, with low-density neighbourhoods and homes segregated from work, shops and other parts of our lives.

“If you make things smaller and more compact, it improves pedestrian and cycle safety but also cuts down traffic incidences for drivers.”

That car-oriented plan is backfiring.

“If you look at health research in terms of accident rates and fatality rates for both pedestrians and drivers, it turns out that a safer community is one that has very narrow lanes, between 10 and 11 feet wide,” says Greg Morrow, who holds the Richard Parker Professorship in Metropolitan Growth and Change and researches the intersection of health and urbanism in the Faculty of Environmental Design. “If you make things smaller and more compact, it improves pedestrian and cycle safety but also cuts down traffic incidences for drivers.”

Morrow, who sits on the Calgary Planning Commission, says urban design can help with a number of health issues, from traffic accidents to higher rates of obesity. “The way we’ve been building our metropolitan regions in North America over the last 60 years has been very much car-oriented," he says. "That has produced a pattern of development that segregates land uses and leaves all sorts of financial, environmental and social problems." 

Those problems include fiscal deficits, long commutes, loss of agricultural land, privatization of public spaces and fewer public spaces, which reduces how often people can just bump into each other — incidental social interactions that are good for us.

“The healthy community literature tells us a lot about the nature of the built environment and how it can either contribute or not to positive health outcomes,” says Morrow. “It’s everything from the way you design the roadways to the scale of the community to the connection to other communities.”

Encouraging higher density or more social and walkable neighbourhoods is not an attack on cars or suburbs, he says. Rather, it’s a move to create built environments that are good for our health and provide innovative, resilient alternatives for people over the course of our lives, from being single and central to having young families in quiet neighbourhoods to downsizing after the kids have left.

 “It’s not about a war on cars at all, it’s about accommodating choice,” Morrow says. “We want private space, we want big houses, we want big yards and all of those things. But how are we going to grow in ways that reflect how people want to live but also address some of the problems that the last 60 years have created?”

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ABOUT OUR EXPERTS

Joshua M. Taron is an assistant professor of architecture in UCalgary's Faculty of Environmental Design, where he runs the Laboratory for Integrative Design (LID). His current research focuses on structurally intelligent swarms as an alternative to conventional wholesale building demolition by grafting complex morphological assemblies into existing buildings. View Joshua Taron's publications

Dr. Patrick Hettiaratchi, PhD, is a professor of environmental engineering at UCalgary's Schulich School of Engineering. His research interests include sustainable landfill technology, methane biofiltration technology, waste to energy, landfill biocap technology, remediation of sites contaminated with complex hydrocarbons, greenhouse gas emission technology development, optimization of landfill construction and operation, and recycling of construction waste. View Patrick Hettiaratchi's publications

Dr. Caroline Hachem-Vermette, PhD, is an assistant professor in UCalgary's Faculty of Environmental Design. Her key areas of research include high energy performance building envelopes, renewable energy technologies, passive solar design of buildings and communities, energy efficient and low carbon buildings and neighborhood design. View a list of Dr. Hachem-Vermette's publications

Dr. Svetlana Yanushkevich, PhD, is a professor in the Department of Electrical and Computer Engineering at the Schulich School of Engineering. Access Svetlana Yanushkevich's publications

Greg Morrow is an assistant professor in UCalgary's Faculty of Environmental Design. His teaching and research interests are in urban design, sustainability, smart growth, land use reform, planning theory, urban/planning history, housing and real estate development. View a list of Greg Morrow's work