There are usually two important questions that are asked: “Why would you build a Passive House?”—and—“What is a Passive House?”
(See the Accelerator's Passive House 101 section.)
The posts focus on the amenities first including the fact that a Passive House:
needs very little heat;
has filtered fresh air 24/7 regardless of whether your windows and doors are open or closed;
is sealed from bugs / critters, dust and allergens;
has significantly less outside street noise;
has reduced heating and cooling bills by up to 80–90%;
is the path to Net Zero (creating at least as much electricity your home needs via renewable energy i.e. solar, wind, etc.).
Wikipedia defines Passive House well:
“Passive House is a rigorous, voluntary standard for energy efficiency in a building which reduces the buildings ecological footprint. It results in ultra-low-energy buildings that require a little energy for space heating or cooling.
“The standard is not confined to residential properties; several office buildings, schools, kindergartens, and supermarkets have been constructed to the standard. Passive house design is not an attachment or a supplement to architectural design, but a design process that integrates with architectural design.”
You can see more about Passive House including sources for the quote above, the history of Passive House and more by visiting this page on Wikipedia.
Other sources that describe Passive House well —
1. Hans ‑Jorn Eich posted a fantastic video called Passive House in 90 Seconds.
2. I also posted a video that goes further into the amenities of a Passive House as well as a quick primer on how you get there.