New BC Building code energy requirements for houses adopted this year, effective 2014, noticeably lacked revisions relating to ventilation requirements. In short, they simply could not come to consensus in time. Now, a public review is underway in an effort to finalize new ventilation requirements to be implemented concurrently in December 2014. “Deferred implementation” is a fancy way of saying “trying to catch up”. The attached link provides a general outline of the issues, and a link to a survey where you can contribute your thoughts towards the new code language. There are also some good graphics which demonstrate the basics of different types of home heating and ventilation systems.