It’s not necessarily true that building out a high performance home be an expensive endeavor, even though it sounds like it. High performance car comes to mind when thinking of other things that are high performance. In a lot of ways, such a home is about attention to detail: fully adhere the weather-resistant barrier (WRB) and tape and seal all cracks and holes. Consider “ex-sulation” rather than just insulation, which creates a thermal break and keeps the exterior climate from having much affect on the interior climate. So how is it defined?