The macro impact of micro-climates
A Sidewalk Talk Q&A with Goncalo Pedro about shaping our buildings and public spaces to make a more comfortable public realm.
With his PhD in mechanical engineering (fluid dynamics), Goncalo Pedro may not fit the profile of a typical urbanist. But Pedro’s work could have tremendous impact on place-making and city-building — and even radically change our day-to-day experience of cities.
Pedro and his team at RWDI, a firm of Toronto-based climate engineers, are using algorithms to help architects understand not only how their designs can better respond to climate, but how their designs actually shape the climate around them — for good, like providing shading in summer, or bad, like creating harsh wind tunnels.
“We can leverage these tools, and provide this really important feedback to the design team, very early on in the process — which is something we couldn’t do 10, even 5 years ago.” The result, according to Pedro, will be a public realm where we can feel more comfortable outdoors, more often.
Sidewalk Talk spoke to Pedro about the importance of leveraging data, why a “building raincoat” could change life on the street, and the one innovation he’s most excited about for the future.
Let’s start out defining some terms. What is outdoor comfort?
Outdoor comfort, or thermal comfort, is just how people perceive their thermal environment. Everyone has their own perception of how they feel thermally. Some people might be cold, some people might be warm. Thermal comfort is the study of how people feel.
There are generally two big categories that influence thermal comfort, one is physiological. What are the conditions impacting the human body? That means what is the temperature, what is the humidity, how much sun is beating down on the individual, how much wind are they exposed to, what are they wearing, what are they doing, are they running, are they sitting down? That’s the physiological side. All that will have an impact on how your body interacts with the outside.
The second one is psychological. The psychological is a lot harder to pin down. That means, how do we perceive a space? A local, a person that lives in a certain location, might feel that a certain plaza is perfectly comfortable. But someone flying in from somewhere else, where climate is quite different, might go to the same plaza and feel very different. That’s a cultural, or local perception of climate. It’s everything from your expectation to what you’re surrounded by. Someone in a park looking at trees might feel more comfortable than someone sitting in a parking lot. Even though the conditions they’re exposed to are the same. Psychological impacts are almost just as important as physiological impacts.
What are microclimates and why are they important to cities?
The way we describe microclimate is: how buildings change incoming wind patterns and solar conditions and how that impacts pedestrians and people outside. For example, a building can not only block wind, but actually accelerate wind around it. Microclimate refers to how these small structures, buildings, neighborhoods impact the local conditions.
We can create a very difficult, challenging microclimate with buildings, or we can use the built form to improve it. The question is: how do we build buildings, plans, neighborhoods that actually leverage the positive features of the microclimate?
For example, in Toronto, during the summer, when it’s hot and humid, we quite often have a southern wind. Having your streets open to those winds helps a lot. It’s amazing the relief that it gives you. That’s an example of harnessing the microclimate to benefit, in this case, outdoor comfort.
My particular focus over the last few years has been working with planners, master planners, and urban designers as they iterate through their design process. We leverage computational tools to give them feedback on how their designs are stacking up.
Can you explain what these computational tools are doing exactly, and what data sets they use?
We have a group in-house that actually generates climate data. Why do this if we have airports that measure data? Well, maybe your project is in a place in the world where you don’t have a very good meteorological station, or you are trying to extrapolate what the climate’s going to be in 20, 30 years. You need a computational algorithm to calculate that.
We’re trying to push this computation earlier in the design process, so that even at concept design, even if the planners have only come up with basic massing or neighborhood orientation, we don’t have to settle for an Excel Spreadsheet calculation of climate data. We can simulate conditions.
Then we can start to follow what the designers are doing. Almost every iteration they come up with, we can test it and get quantitative feedback. Now when we say an idea is better, we can say it’s 25 percent better for this metric. That quantification becomes very valuable; in a world where everyone wants to design amazing things in shorter and shorter timelines, it becomes important to mitigate risk, and these tools allow us to do that.
You mentioned that this data can be useful, even if the planners are still at basic massing stage. Would you say that the choice of massing, orientation, and street grid is fundamental?
Absolutely. It’s critical. Fixing your neighborhood and street orientation, your street signs, the way your neighborhood interacts with the climate in general — those first steps could make or break the project.
Of course, sometimes you have no choice. If you’re designing a neighborhood, you might be constrained by the street grid that exists there. In that case, there’s limited choices. But in places like Toronto’s waterfront, where you have, in essence, a blank slate, these are things that we need to think about. Can we change the way we approach it to really maximize benefits?
Can you give me an example of a simple design choice that would have a very big impact?
Street orientation, that’s a huge one. In a place like Toronto, where wind blows more or less east to west, if you have your main streets oriented with the main cold winds, then you’re really exposing those streets to uncomfortable conditions. Having that understanding right off the bat, and quantifying that, allows the design team to make choices. Maybe you don’t want your main arteries to go in a certain direction.
Another choice, on the massing side — it’s very common to see towers with podia in Toronto. Towers redirect strong winds down to ground level; the podia are there to stop that from happening, they protect pedestrians from excessive wind. So, where should you put the tower on the podium? Can you shove the tower right up against one corner? Do you need to push it back and have it recessed? All these questions can be tested.
Working with Partisans, you’ve helped develop a “building raincoat” for the Sidewalk Toronto project. Does the raincoat act as an extension of the podium?
Yes. Placing a canopy, like a raincoat, around a building is a further measure to control wind and sun. They create very convenient spaces for people to inhabit and use, a natural extension of whatever commercial space you may have.
But the raincoat also provides a level of transition. Generally with buildings we have the outside and we have the inside. You have this very sharp edge, right? You enter through the door, you’re in an indoor environment. You exit through the door, you’re in an outdoor environment. With the raincoat, we are now providing a level of transition in what people feel. You can approach the building and go underneath this raincoat and maybe have lunch at a restaurant there and feel like you’re outside. Maybe it’ll protect you from the rain. Maybe there’s some heating in there.
This level of transition is interesting because it not only allows people to choose where they want to be, depending on time of year and conditions and comfort level, but it also gives businesses and commerce a lot more flexibility in how they want to serve the public. A restaurant might actually have several patios. It might take down the one that’s outside the raincoat in the winter, but maybe keep operating the one that’s underneath the raincoat. It all depends on how they perceive the level of comfort.
You work often with architects and designers and, I would imagine, developers — are these kinds of transitional space becoming more common?
They are because they maximize public space usage. In many places in North America, Toronto included, we haven’t really been able to replicate what happens in Europe, where you have these plazas and cafes with outdoor patios people can enjoy. What we’re seeing now is this real drive to make use of these spaces. A very good example is — have you heard of the King Street streetcar project?
Yes. They closed off the car lanes to everything but public transit and taxis, right?
Correct. So you can’t drive through; you can drive on it, but you have to always turn right at the end of the block. It really cut down on the amount of car traffic, to the point where it looked almost desolate. Businesses were given the opportunity to create these outdoor seating areas, patios on the street, that people are very into. I think that shows a mindset change. We are trying to get outside, use the outdoors a lot more, enjoy the open environment. It really signals a shift to more of that European approach, where businesses spill out onto the sidewalk and pedestrians, in essence, take over. And businesses depend on the patios to bring in a significant amount of revenue. If we can create these spaces that are comfortable and, effectively, extend fall and spring, that changes the game for a lot of businesses and people.
I don’t know if you’ve been down into the PATH [Toronto’s underground pedestrian tunnels]. It’s a very efficient system, connecting the business district to transit. In very cold times, it does provide this easy conduit — you don’t even have to put on a coat to go eat lunch. But we’re seeing a desire to get away from that kind of system, to take back the surface and create really interesting public environments. Part of that is making them as comfortable as possible.
Are there any buildings or neighborhoods that are inspirational to your work?
A lot of the older European cities, the way they were designed was driven by trying to improve outdoor comfort and making sure that the streets are responsive to climate in general. If you go to a place like Venice or Rome or even Paris, in the winter, you’re generally protected from excessive winds, and you’ll have a variety of shading and solar conditions within the space. This variety’s important because it allows you to choose where you’re going to be at different times of the day. That flexibility is something we want to replicate in our designs.
Is there an innovation in thermal comfort that you’re most excited about for the future?
We’re starting to see people incorporating sensors into bikes and phones and backpacks and things that actually provide a lot of information to, not only people like me, but cities, which are trying to get a hold of better data. For example, in Toronto, we lack a good air quality sensor network. There are some groups of volunteers that walk around with air quality sensors and collect data. That data can then be processed and we can get this sort of transient, time dependent, spatially-varied data set that can be used to drive a lot of decision making processes.