Energy conservation building codes written after the energy crisis of the early seventies, became a major disruption to many past well established building techniques. The reactive sealing up of buildings to prevent heat escapement, caused an immediate deterioration to interior air quality. Secondly, an “improved” vapour barrier requirement behind the interior drywall, now prevented any chance of feedback (no wet patches on the inside face of walls and ceilings) to indicate that the building’s weathering envelope was failing, until major wood framing damage occurred. In other words, this new vapour barrier requirement kept any rainwater penetration into the wall and roof system contained and hidden. That really is it, in a nutshell. This lack of feedback, to the trades people, would automatically leave them reassured that no rainwater was entering the building wall and roof components. They would have believed that all is well, for “the building seems dry, even in heavy rains”, so their job was well done. “No need for flashing and other weathering improvements as there are no leaks into the building whatsoever”, was a probable conclusion. “Perhaps we can be a little less fussy in the future with these outside details”, a trades person may have surmised. In other words, on lacking suitable feed-back, the trades people were given no indication at all, that rain could be leaking into the walls. Suitable feed-back is crucial, good or bad, in order to recognize if what has been done, is working as intended. There was also no feedback or obvious indication to the building occupier that water was causing the insulation to become wet and the wood framing beginning to rot. It seems that there were no “what if” questions thought about when designing this interior air tight vapour barrier. In other words, “what if rainwater entered the walls, and how would we know that such had occurred before any major damage was caused?”. This whole thing should have been properly thought out, before being put into practice. While it is perfectly true that this air-tight vapour barrier works ideally to prevent heated humid air exfiltration into the building insulation, this is only half the story. Yet, this is not the end of such foolishness in building code writing, as we merrily progress along in attempts to save the planet, without a more thoughtful and global approach to the problem. The question is, how could such foolishness have occurred? Well, this is an important point, which is discussed in detail within the content of this website. The “Longer Introduction” highlights some of the more specific details that are discussed within the commentary.