Passive House Savings Calculator

The Passive House Savings Calculator is a tool designed to estimate the potential long-term financial benefits of investing in a Passive House compared to a home built to standard building codes. It highlights how the upfront investment in superior energy efficiency translates into significant savings on heating and cooling bills over the lifespan of the home.

How the Calculation Works

The calculator compares the estimated annual energy costs of two hypothetical homes: one built to standard code and one built to Passive House standards. The core of the calculation is as follows:

1. Standard Home Annual Cost: This is calculated based on the home's square footage and an average energy cost per square foot for conventional construction. This average is derived from national or regional data on typical heating and cooling expenses.
2. Passive House Annual Cost: A Passive House is designed to be extremely energy-efficient, typically using up to 90% less energy for heating and cooling than a standard home. The calculator applies this percentage reduction to the standard home's estimated energy cost to find the Passive House's much lower annual cost.
3. Annual Savings: The difference between the standard home's cost and the Passive House's cost gives you the estimated savings for one year.
4. Lifetime Savings: This figure is projected over a 30-year period (a common mortgage term) to illustrate the substantial long-term financial advantage. It simply multiplies the annual savings by 30, providing a powerful look at the cumulative benefit.

Practical Example

Imagine you are considering building a 2,000 square foot home.

• A standard home of this size might have an estimated annual heating and cooling cost of $2,400 (based on an average of $1.20/sq. ft.).
• A Passive House of the same size, being 90% more efficient, would have an estimated annual cost of just $240.
• This results in an annual saving of $2,160.
• Over 30 years, this simple saving accumulates to an impressive $64,800, not even accounting for potential energy price inflation.

The Core Principles of Passive House Design

The dramatic energy savings are achieved through a set of core design principles:

• Superinsulation: A thick, continuous layer of insulation around the entire building envelope minimizes heat transfer.
• Airtight Construction: A meticulous air barrier prevents drafts and uncontrolled air leakage, which is a major source of energy loss.
• High-Performance Windows: Triple-pane windows with insulated frames are used to prevent heat loss in winter and heat gain in summer.
• Thermal Bridge-Free Design: Careful design eliminates "thermal bridges," which are spots where heat can travel easily through the structure (e.g., through studs or foundation edges).
• Mechanical Ventilation with Heat Recovery (MVHR): A balanced ventilation system continuously provides fresh, filtered air while recovering heat from the outgoing stale air, retaining up to 90% of the heat.