Many things need to be sealed. Like a passive house. Like icecream. When we want to control an environment to protect something, or to keep it stable, or to keep it fresh, we generally need to seal it.
Even if we decide to open the container (when it suits us), we need to seal it when we want to control the indoor environment.
If you don’t seal the icecream container, it will melt.
Like a house, office building, hospital or school. We should seal them so that we can keep out unwanted cold air or hot air.
Even though we can choose to open windows when it’s nice outside.
And let’s not forget a properly designed ventilation system, even in a commercial building when you can’t open the windows.
In a properly designed passive house (not passive solar, passive house standard), you seal up the building AND think about ventilation at the same time.
Hence my sourceable article, which generated quite a bit of debate. Check it out. NATHERS Scheme based on untested premise.