> The fact that a house needs to be pressure tested seems insane.

What's the alternative, building intentionally leaky houses? Better to be able to control the leaks to your benefit, aka active ventilation.

> Sure you can leave the windows open, but that defeats the purpose.

Actually the purpose of wind-ows is to let the wind in - no pun, that's the actually etymology of the word, (also in Spanish: ventana originally meant "for venting").

Even in an old air-leaky house if you don't open your windows, the ventilation is happening through your walls, using them as an air filter which they were not designed to be, and in the process pulling moisture through them, which can cause all kid of bad stuff to grow in them. You shouldn't rely on such passive depressurization for ventilation, as it depends totally on pressure differences between indoors and outdoors.

> Most modern houses need air condition or at least ventilation systems, because they need to be so energy efficient, that there is no other way to get fresh air in.

There absolutely are ways to get fresh air in and dirty air out, including the following:

- Exhaust ventilation systems (i.e. whole home extractor fans)

- Balanced ventilation systems

- Energy/Heat Recovery Ventilation systems.

The poorly ventilated houses you are referring to were built between the 80s and 90s - yes they have ventilation issues. I know this because I own such a house and have fixed the ventilation issues with solutions from the list above.

Today in most areas, some form of mechanical ventilation is required by code on new construction, and has been for 15 or so years.

> The air in a modern home is often so dry that my nose start running the minute I enter. I don't want to live in that sort of climate.

In cold climates, the ability to safely humidify a house depends mainly on having good enough insulation and air sealing that the indoor humidity doesn’t condense on cold surfaces and rot the building. This is especially relevant near windows.

So if you want decent indoor humidity when it’s genuinely cold out, you want double- or triple-paned windows with insulated edges, proper air sealing near the windows, and possibly even an energy recovery ventilator.

(Or you can live in an old house, spend stupid amounts of money to heat it all the way to 63 degrees for a few hours a day, be cold and dry, and wonder what the heck anyone was thinking when they designed their single-pipe steam heating system.)

P.S. It is supposedly possible to properly design a single pipe steam heating system that achieves a comfortable temperature in more than one room. If so, I have never seen such a thing.

> Sure you can leave the windows open, but that defeats the purpose. Modern home needs to be ventilated three times a day, that means opening all the windows in the morning, when you get home in the afternoon and before going to bed. How many people will remember to do that?

I don't really understand your objection. in a leaky old style building without an effective moisture/thermal barrier, you don't get to choose whether ventilation is happening; it always is. with modern sealing, you can open the windows if you prefer fresh air, or you can enjoy much more efficient AC/heat if you don't. why couldn't you live in a modern home and just leave the windows open? it's easy to get a good draft going in any multifloor building with windows.

Most new homes today include heat recovery ventilators that continuously cycle the air from outside.