Passive House Savings Calculator

A Passive House (Passivhaus) is a rigorous, voluntary building energy standard that achieves very low space heating and cooling demand through superinsulation, airtight construction, heat-recovery ventilation, and careful thermal-bridge-free design, typically capping space heating demand at 15 kWh per square meter per year.

Annual heating energy in kWh equals the building's floor area in square meters multiplied by its heating demand in kWh per square meter per year. This calculator computes this figure separately for the conventional building and the Passive House scenario, then multiplies each by the energy price to get annual cost.

15 kWh/m²/yr is the certification threshold set by the Passive House Institute, chosen because at that level a building's peak heating load becomes small enough that a full conventional heating system can often be replaced by a much smaller supplemental system, sometimes just the ventilation air itself, dramatically simplifying and reducing building services.

Payback period in years equals the extra upfront construction cost of building to the Passive House standard divided by the annual energy cost savings. It answers how many years of energy savings it takes to recover the additional construction investment, before accounting for financing costs or future energy price changes.

This calculator focuses on space heating demand, the primary metric used in Passive House certification and most conventional-versus-Passive House comparisons. Cooling savings can be significant too in hot climates but follow a similar calculation with cooling-specific demand figures.

Both conventional and Passive House energy use scale linearly with floor area, since demand is expressed per square meter. A larger home has proportionally more energy use in both scenarios, so the absolute dollar savings grows with floor area even though the percent reduction stays the same.

Compared to a typical existing building, Passive House construction commonly reduces space heating demand by 75 to 95 percent, largely because superinsulation and airtightness address the two biggest sources of heat loss, conduction through walls and roof, and uncontrolled air leakage.

Usually yes, due to thicker insulation, higher-performance windows, heat-recovery ventilation equipment, and more rigorous airtightness detailing. The extra cost premium has been falling over time and varies widely by region, climate, and how experienced local builders are with the standard, entering your own estimate gives the most accurate payback figure.

Yes. Enter the renovated building's projected heating demand as the passive value and the pre-renovation demand as the conventional value, along with the renovation cost as the extra cost, to estimate the same energy savings and payback metrics for a deep energy retrofit (sometimes called EnerPHit).

Higher energy prices increase annual dollar savings for the same energy reduction, which shortens the payback period. This calculator lets you test different energy price assumptions to see how sensitive the payback period is to future energy cost changes.

The chart plots annual heating cost for both the conventional and Passive House scenarios as floor area varies, holding demand and price fixed. The growing gap between the two lines as floor area increases visually shows how absolute savings scale with building size, with a marker at your entered floor area.