The mainstream approach to sustainable design is business-as-usual architecture with some easy bolt-on “sustainable features.” Easy solutions like this are what got us into the current mess: buildings contributing 40% of our CO2 emissions as we enter the anthropocene. (Have you read my manifesto?) Designing to the passivhaus standard means accepting more constraints and this requires more effort; it’s not an easy solution. A rigorous process must be followed. However, the passivhaus standard is actually very simple with clear performance benchmarks that must be met. And the results are simple: no complex offsetting or complex carbon calculating is necessary.

Passivhaus buildings simply reduce energy consumption and CO2 emissions, by design.

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Easy solutions are the problem

Relying on bolting easy “sustainable” solutions onto business-as-usual architecture is part of the reason why we are in the current Climate Change crisis. This is a reflection on wider society. We are living in fast paced times and always looking for quick fixes and easy answers. So we’ve kept on designing buildings that perform poorly and looking for easy solutions to add-on to make them comfortable and functional. First we waste energy operating a poorly performing building, then we consume more energy in an attempt to makes the building comfortable and functional. And, then we add “sustainable features” as an easy solution to make the building “sustainable.”

The obvious example is one we all know, the ubiquitous all-glass building. This kind of building boils as the sun adds even more heat to an interior that has already been warmed by the heat of the people and equipment in the building (and heating!) And then the building guzzles even more energy still, working hard to chill the inside to a comfortable temperature. You know, ‘Iced-tea buildings’.

It is much better to get the design right so the building can be comfortable with minimal energy input in the first place, and this means accepting certain constraints.

Embrace Passivhaus Constraints

This is what designing a passivhaus building requires: accepting and embracing constraints. Additional constraints over and above the usual architectural constraints of time, cost, site, location and project resources etc.. Architects and designers are actually pretty familiar with constraints!

Firstly, passivhaus makes explicit the constraints of building physics that exist anyway but are usually ignored. The laws of physics don’t mind if we ignore them or not though, they still hold true, so business-as-usual buildings perform poorly. Just as a bucket full of holes won’t hold more water, no matter how much water is added, physics simply won’t allow business-as-usual buildings to perform any better, regardless of any add-on “sustainable features.”

Secondly, passivhaus includes occupant comfort constraints and energy consumption constraints. These constraints are actually very familiar as most building codes or regulations include them, just with lower benchmarks and typically with less rigorous calculation methodologies. The higher benchmarks, and the detailed process that the passivhaus standard requires, means more work must be done. The constraints need full consideration and integration into the design process, rather than a cursory check once the design is almost complete.

Constraints that are accepted and embraced as part of the design process fuel creativity, not compromise. Constraints lead to tighter, leaner solutions: to simplicity.

Simplicity; you have to do the work

The simplicity of the passivhaus standard lies in having crystal clear targets. To have any certainty about reaching an ambitious target, a clear aim and rigorous discipline is needed. And then you have to tread the full path from the starting point to the end destination, doing all the work needed in between.

We can be tricked by surface appearances into thinking that minimalist design requires minimal effort to produce. The same is true of simplicity; we can mistakenly assume it can be produced with little effort. The reality is almost the opposite though; simplicity requires hard work and creativity to produce. Complex outcomes are rather more straightforward, business-as-usual in fact. Creativity is about being able to embrace constraints and produce simple elegant solutions that appear natural and effortless.

And this is what the passivhaus standard is all about. Embracing constraints. Taking a rigorous integrated design approach. Giving close attention to the details of the construction and building physics. And applying creativity to produce simple elegant solutions. We have to do the work.

Business-as-usual architecture is not the solution.

We need to stop looking for quick-fixes and easy solutions to add-on to business-as-usual architecture. Climate Change demands that we embrace the constraints of building physics, occupant comfort and energy consumption. It demands that we do the work to deliver deep reductions in energy consumption and CO2 emissions.

These demands are simple, but not easy. The passivhaus standard is a simple solution that delivers the necessary reductions in energy consumption and CO2 emissions, by design.

Wondering what kind of buildings result from embracing passivhaus constraints? Why not check out the winners of the 2014 Passive House Awards, which include single houses, apartment buildings, education buildings and even a museum.

9 thoughts on “Passivhaus: Simple but not easy

  1. […] ‘Zero-Carbon Buildings’ must generate enough ‘Zero-Carbon’ electricity to export to the grid to cover the actual consumption at the building, and to cover the additional CO2 emissions from when the building uses electricity from the grid. Complex unreliable offset accounting is required to actually get to ‘zero’. In contrast to this, using less energy in the first place is simple and reliable and doesn’t require any offset accounting. […]

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