What is better? Net Zero or Passive House?
In post Pandemic era, many talks/efforts have been made to retrofit old buildings in the architecture and construction industry.
With social changes brought on by the Pandemic, WFH, and Great Resignations, thinking about empty buildings and how to use them would be the next obvious step in our future planning.
However, compared to the past, one difference is that its emphasis on typical energy consumption has changed to a health and wellness focus.
Instead of focussing solely on energy consumption or financial implications, the focus has been shifted to our recently developed obsession: health and wellness.
A few weeks ago, I attended the City of Toronto’s Deep Retrofit Challenge webinar as part of my work. The webinar introduces the city’s effort to present building owners/developers to retrofit their existing buildings. The aim was to decrease energy consumption which helps to contribute to a more significant objective: climate change.
Minimizing environmental impact by considering old buildings and transforming them into sustainable, low-energy green buildings is critical in the climate change objectives.
The typical discussion of energy consumption and its financial implication has been discussed with another typic: the health and wellness of building tenants.
The topics of retrofitting existing buildings and their usual energy/financial advantages are well known in the architecture and construction industries. At this webinar, discussing the current and future tenants’ health/wellness wish lists and the energy discussion created a lively conversation.
As an architect focusing on creating energy-efficient/less carbon footprint buildings has always been THE goal. The new emphasis on one’s health and wellness in such structures, coupled with a past obsession with energy consumption, creates a renewed urgency.
Definitions for these two terms: Netzero and Passive House
I have used these two terms without overthinking them in the past.
Both describe the green building efforts for using less energy/ smaller carbon footprint, which contributes to mitigating the negative consequences of climate change.
With this casual understanding, I decided to find the accurate, scientific definition for these terms, a.k.a. googling.
- Passive House
Passive House Institute defines a passive house: “Passive building comprises a set of design principles used to attain a quantifiable and rigorous level of energy efficiency within a specific quantifiable comfort level.”
Another way to describe the term is that it “optimizes gains and losses” based on climate.
- Netzero Building
A net-zero home produces as much energy on an annual basis as it consumes. Design and engineering usually involve off-the-shelf energy-efficient technology and renewable energy sources, such as solar panels, to reach zero net energy use throughout the year.
It may not necessarily be engineered entirely to use the lowest energy possible. Still, if it produces enough to compensate for those shortcomings, it could be considered net-zero.
These two standards clearly have the same goal (WHAT) of creating green, energy-efficient, sustainable buildings. The differences lie in the HOW TO part of implementing those goals.
Upfront Cost justified
Like many (or ALL) things in our life, both Netzero/Passive House standards require our commitment…especially financial ones.
Despite the “eventual” financial gains from implementing these standards on our buildings, they are challenging to execute due to initial cost.
I had several discussions with past and potential clients about this forever debated difficulty in retrofitting the old buildings.
Projecting the initial cost (consistently high) and coming up with “potential” gains from such initiatives have always been the challenges for building owners to overcome.
We ( including building owners/developers) understand the benefits of retrofitting old buildings or building new houses with the Passive House standards.
They understand the math of recouping the energy cost over time… just “how much over” stop in their track.
However, experiencing the Pandemic and its subsequent emphasis on health/wellness in our physical environments push us to view these efforts differently: not just in financial calculations, but in the essential qualities, all of us look for.
The Pandemic changed many things… Including our priorities.
I believe this seismic shift in our thinking would significantly impact how we view/plan our present and future.
Considering the initial cost involved in retrofitting the existing building or developing a new building with even a higher initial cost would be the total must starting point.
Beyond Energy Efficiency
Our past discussions on retrofitting/passive house standards have focused primarily on energy consumption and its financials.
However, the climate change urgency and also the Pandemic induced priorities changed our views on how we want to live now and in the future.
Like the social changes- WFH and Great Resignations– we are going through, we are rethinking our physical environments and how we want to live.
I believe our past financial obsession (aka energy) in the design/construction industries would have another equally (if not more) focus. Creating a healthy physical environment for us to thrive now and later would be such a priority.
Seeing the various interest from the recent webinar, it was clear we are moving from the usual financial discussion (although there was some of that) to future focussed topics.
I realize the question, “what is better,” is incorrect, especially in the post-pandemic time.
Instead, we need to ask the “where” question regarding Net Zero or Passive Building discussions.
In the context of old/existing buildings, deciding between these two standards to achieve the COMMON goal of the green building would not be accessible with many variables.
However, as the saying goes, the greenest building being the existing one, we should always start with the attitude of what to improve rather than the costly demolishing and rebuilding.
Editor’s Note: This post was originally published in Life Outside of Design Studio and has been updated for accuracy and completeness.
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