For someone outside the building sector, many of the shorthand symbols frequently used in Passive House related content – including educational videos, press releases, webinars, and even some of our other blog posts – can be quite confusing. What the heck is a U-value? What are all those different subscripts? And what the heck is this symbol -> Ψ? Don’t fret. We will get into all of those, as well as an explanation regarding their relevance to Passive House design in this handy guide!