Envelope upgrades refers to improving the thermal efficiency of a building through insulation, replacing windows and reducing the leaks.

 

Envelope upgrades tend to be very expensive. As such, the financial returns based on energy savings alone are very poor.  Envelope upgrades are generally addressed when there are other factors that are impacting the use of the building.  For example, if the insulation in a building has been damaged (e.g. water leaks), then an upgrade is required for the health of the building.  For example, if the windows are leaking, then occupant comfort is impacted and may require window replacements.

 

When an envelope upgrade is required (for non-energy savings reasons), we recommend leveraging modern technologies.  For example, when replacing windows, select window systems that are triple pane and have glazing to reduce the energy demand.  If the exterior cladding needs to be replaced, consider replacing with a solar wall or solar PV in place of standard cladding materials.