Session · Retrofits and EnerPHit · Designers and consultants

From One Apartment to Many: Replicable EnerPHit Retrofits Across Climates

Francesco Nesi, ZEPHIR Passivhaus Italia · March 5, 2026 · Chapter · PHNE (Northeast Passive House)

EnerPHit retrofits delivered one apartment at a time, from Casa Baretti in Bergamo, the first EnerPHit certification for a single apartment, to projects near Naples, and how the approach adapts across climates and scales up.

Key points

• How unit-based EnerPHit retrofits differ from whole-building ones.
• Managing condensation and mold risk in interior insulation retrofits.
• Thermal-bridge strategies under tight architectural constraints.
• Airtightness as a quality-control process, with staged blower-door testing.
• How unit-level pilots can build a scalable market with local supply chains.

Topics: Retrofit