Design Solution · Building Envelope
Design Solution · Dream about it
Passivhaus-grade fabric upgrade of an existing building to slash heating demand.
An existing masonry/concrete frame is upgraded to Passivhaus EnerPHit standard with continuous insulation, airtightness and high-performance glazing. Cutting fabric heat loss reduces the size of mechanical plant required. Retaining the structure avoids the embodied carbon of demolition and rebuild.
EnerPHit is the Passivhaus Institute's defined standard for retrofit, and applying it to an existing masonry or concrete frame — continuous insulation, an airtight layer, and high-performance glazing — is the most robust way to cut regulated heating energy in an existing building while retaining the embodied carbon locked in the structure. The standard itself is well established, with a growing body of certified EnerPHit projects across Europe providing performance verification, so the approach is not speculative. The project-specific claim is unverified: no airtightness test results, no modelling outputs, and no measured energy consumption after occupation are cited, so whether EnerPHit performance was actually achieved or simply targeted remains open. The practical challenges in retrofit are significant — thermal bridging at junctions with the existing frame, continuous airtight layer installation around existing penetrations, and interstitial condensation risk if the insulation strategy is not carefully detailed — and a specifier should require measured post-completion airtightness data and confirm the design has been checked by a certified Passivhaus designer rather than treating the label as self-certifying.
#enerphit #airtightness #insulation #embodied carbon