Why Smart Cities Need Passive House Buildings

Passive House is the best building standard to bring the physical infrastructure of the smart city up to the level of the digital infrastructure.

Thanks to Sidewalk Labs’ announcement of their massive waterfront project in Toronto and Bill Gate’s $80 million purchase in Arizona, news about smart city development has been popping up more frequently than ever. Most articles talk about the sleek, sexy autonomous electric vehicles that will be whizzing around the traffic-free streets or the Internet Of Things devices that will sense and track everything from the contents of our fridge to our morning commute. What you don’t see in headline news is how the skeleton of this complex, high-tech web will be constructed. Because no matter how excited we get about the newest gadgetry, we will still open a door every morning to leave our house, we will still sit in a chair when we get to work, and we will still spend all day in a building. You can't build a city in the cloud, you build a city by building buildings.

Two of the driving values behind the smart city movement are 1.) a lowered environmental impact from urban centers and 2.) an increased standard of living for urban dwellers. Technology is employed to achieve these goals by providing real-time data on the operation of all the systems that make a city run: plumbing, lighting, heating and cooling, electricity, etc. This data will allow for proactive management of these systems, enabling the most efficient use of resources in the dense urban area and minimizing the number of damages and outages. The purpose of the data is to maximize the efficiency of the systems. This can be a heavy (and necessary) lift when applied to existing, aging infrastructure. But when you’re building a smart city from the ground up, you can integrate efficiency and comfort into the design of the physical infrastructure too. A truly smart city needs a physical infrastructure that is just as efficient and innovative as the digital infrastructure that commands it.

Now if only there were a building methodology that had the same priorities of achieving environmental sustainability and a higher standard of living through increased efficiency of resource usage…

The Medium Is The Message


Enter: Passive House. Heard of it? If you're a regular reader of ours, you have, but that makes you the minority. The vast majority of the building world, and a significant portion of the green building world, have never heard of it. We talk to sustainable building consultants from San Francisco to Nova Scotia who don't realize it's even an option.

This is why it's vitally important that we continue to describe and relay the reasons why this standard is the best bet we have for the future of building. The principles behind the standard are simple- create an airtight, highly insulated building and you will need drastically less energy to condition the space. Passive House has been called the “stupid simple” of architecture, going back to basics in building science. Each building is itself a message to others that says: we made a dent in climate change, and you can too. All the more reason for high visibility and forward-thinking projects to put Passive House front and center in the design process.

Passive House and Grid Alternatives

In order to reduce greenhouse gas emissions and lower their environmental impact, many smart city developers are looking for alternatives to the fossil-fuel heavy electricity grid. The main contender for a grid alternative is renewable energy deployed locally on a district energy network. A renewable grid opens up the possibility of creating not only a city with a much smaller carbon footprint but a net-zero city. Unfortunately, there are some very tangible barriers to making a renewable grid scalable for use across even a small city.

The largest barrier is the sheer size of the energy demand of a modern city. Advances in technologies such as photovoltaics and wind turbines are working to make it feasible to meet the energy demand with solely renewable energy sources, but the space required to generate this renewable energy is still a major concern. Even if you covered the roof of every building in a city with solar panels, you could not generate enough energy to power the city. To power Manhattan with solar for a year you would need 12,800 sq mi of solar panels, over 550x the size of the city. In order to make renewable energy feasible, we need to drastically reduce our cities' energy demand.


Passive House and alternative energy have been successfully implemented on the neighborhood scale in the past. The Bahnstadt city district in Heidelberg, Germany combined multiuse Passive House buildings and a renewable district heating network to achieve a neighborhood with net-zero annual carbon emissions.

This year’s North American Passive House Network (NAPHN) Annual Conference was dedicated to Passive House + Renewables, and how these two technologies can support each other to create a net-zero future. 475 has helped many projects achieve Passive House performance with sustainable solutions and product support: airtightness with Pro ClimaLunos HRV ventilation , Daylight with Lamilux PHI certified skylights and Gutex woodfiber insulation.

If It Ain't Comfortable, It Ain't Sustainable

The 40% of the US energy budget going to buildings is being used to keep us comfortable. When you put it this way, it starts to make more sense- we’re spending our energy on controlling our indoor environment so that we can be comfortable throughout the day. With the average person spending 90% of their lifetime indoors, this may seem like a reasonable investment. Right?

If you are indoors right now reading this, I want you to take a moment to assess your comfort level. Are you too hot? Too cold? If you walked around the room you’re in, would some parts of it be different temperatures than others? If we’re spending this much energy on our buildings, why do so many people have space heaters under their desks at work, or sleep with either a fan or hot water bottle next to their beds at home? Why do we need apps like Comfy to regulate the microclimates that are created in a 2000 sq ft office? It’s because our buildings aren’t functioning how they should be. So until we fix the structural problems with our buildings- air leaks, thermal bridging, single pane windows, etc- no matter how much energy we use to pump them full of hot or cold air, they still won’t be consistently comfortable.

We can keep building our cities to old standards, and, down the line, keep layering on quick fixes like so many bandaids on a broken leg. Or, we can elevate our building standards to the demands of modern urban life. A city is an ecosystem that includes physical, mechanical, and digital systems, and to rethink a city requires innovation in all of these realms. Passive House is the leading innovation in the built environment and it is a standard of building ready to bring our cities into the future.

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