# Passive House Savings Calculator

Created by Bogna Szyk
Reviewed by Steven Wooding and Jack Bowater
Last updated: May 22, 2020

If you plan to build a house and wonder whether the additional costs of making it energy-efficient are worth it in the long term, this passive house savings calculator might be just be the tool for you. It will help you choose between a regular building, an energy-efficient house, and a passive house project. Read on if you want to learn how to calculate the prospective savings, what the differences are between passive and energy-efficient homes, and how to ensure maximum sustainability of your building.

## Energy-efficient house vs passive house

You probably heard a lot of various terms like green buildings, sustainable buildings, or passive houses. The main differences between them are:

• An energy-efficient house is a building that uses less energy than specified in the standards. For example, in Germany, such a building has the energy use of less than 50 kWh/m2 per annum.
• A passive house is a building with an extremely low energy use, not exceeding 15 kWh/m2 per annum. A conventional heating system is not needed in such buildings.
• A zero energy house has a net balance of energy equal to zero. It doesn't mean that it doesn't require energy at all, but the energy such a building takes from the power grid is equal to the energy supplied to it.
• An energy plus house generates a surplus of energy during a year.

## How to calculate passive house savings

1. Start with the parameters of your house. Determine the total area of your house and how much it cost to construction (per square meter).
2. Check with your local gas supplier how much it costs to heat your house. Type the price of gas per cubic meter into the calculator.
3. Determine any additional costs required to make your house energy-efficient or passive. By default, these values are set to 9% and 15%, respectively, but you can change them at your will.
4. Let our passive house savings calculator do the rest for you. It will return how long it will take for your investment to be returned.
5. You can also use the advanced mode to customize values such as:
• How much energy is supplied from one cubic meter of gas.
• What is the annual energy demand of a regular house.
• What is the annual energy demand of an energy-efficient or a passive house.

## Passive house characteristics

Some sample features of a green building are listed below:

• Passive houses tend to have compact structures - this means that the ratio of the area of external partitions to the volume of the house is as small as possible. What this means is the structure minimizes heat loss through partitions.
• Transparent partitions (windows) are used mostly on the southern side (in the northern hemisphere), where the heat gains and light from the sun are highest. No windows are placed on the northern elevation. Swap the directions if you are reading from the southern hemisphere.
• Special windows and doors with very low heat transmittance are used. It minimizes the losses of heat through such openings.
• Sustainable energy sources, such as solar panels, tend to be used. It is also popular to install heat pumps and recuperators.
• Special insulation materials are used to reduce the heat transfer through the walls to a minimum. If typical materials are used, the insulation is substantially thicker than in regular houses.
• Energy-efficient houses are built to maximize the proportion of natural light in lighting. At nighttime, low-energy lighting such as LED lamps are used.
Bogna Szyk
Size
ft²
Gas price
$/m³ Regular house Construction cost$/
ft²
Construction cost
$Heating cost$/
per year
Highly energy-efficient house
%
Construction cost
$Heating cost$/
per year
Investment returns after
years
Passive house
%
Construction cost
$Heating cost$/
per year
Investment returns after
years
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