Passive House Calculator

Evaluate whether your building meets Passivhaus (PHI) certification criteria for heating demand, cooling demand, primary energy, and airtightness.

Floor Area (sq ft)

Thermal Envelope Area (sq ft)

Average U-Value (Btu/hr·ft²·°F)

Airtightness (ACH50)

Heating Degree Days (HDD65)

Cooling Degree Days (CDD65)

Passive Solar Gain (%)

Tab to move between fields

Heating Demand (kWh/m²/yr)

2.6

Cooling Demand (kWh/m²/yr)2.4

Primary Energy (kWh/m²/yr)34.9

Airtightness (ACH50)0.5

Peak Heating Load (W/m²)7.5

Passivhaus Certifiable1

Internal Gains3,344.4

How to Use This Calculator

Enter Floor Area and Thermal Envelope Area in sq ft.
Enter Average U-Value of the entire envelope in Btu/hr·ft²·°F and Airtightness in ACH50.
Enter Heating and Cooling Degree Days for your climate and Passive Solar Gain percentage.
Review Specific Heating Demand in kWh/m²/yr — Passivhaus limit is ≤ 15 kWh/m²/yr.
Check Peak Heating Load in W/m² and Passivhaus Certifiable status against all criteria.

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