Existing homes that are either poorly built or simply due for upgrades can look to the Passive House Institutes retrofit standard called EnerPhit. If your home wastes energy and is uncomfortable or unhealthy to live in, the EnerPhit Standard provides a proven step-by-step pathway to dramatically improve energy efficiency, thermal comfort, acoustical comfort and indoor air quality.
In an ideal situation, a complete retrofit would be done all at once. But the financial reality of some do not permit, so the solution is to plan the retrofit in phases. This is done by assessing the current condition of major building components; roofing, cladding, doors & windows, mechanical equipment, etc. Each part has a life span, and can be prioritized according to how far along they are in their respective lifecycle. Then the Passive House Designer will group various components into retrofit phases 1-2-3-4… the grouping may not necessarily follow deterioration priorities. For example; When changing cladding, windows can be better installed at the same time. When making the envelope more airtight an HRV/ERV may need to be introduced to avoid condensation issues.
Avoid poor planning cost lock-In
If you do it, plan it right from the start! Unrehearsed Ad hoc renovations often lead to missed opportunities. These works often interfere with the methods a Passive House Designer would have preferred and are then too costly to undo = poor planning lock-in. A deep energy retrofit requires a master plan, tailored in phases if necessary. A Passive House Designer will be considering each phase’s effects on the buildings proper functioning as a system. Each component effect the building as a whole; moisture balance, fresh air changes, surface temperatures and more.