What is Passivhaus? Should I make my house a passive house?

PassivHaus (Passivehouse), PHIUS

PassivHaus is a standard for low-energy or zero-energy houses. It was developed in Germany by the PassivHaus Institute. There is a U.S. branch of the PassivHaus Institute called the Passive House Institute US or PHIUS. PassivHaus certification requires compliance to their exacting standards for both building materials and methods of construction as well as the final result in terms of energy efficiency. Every element of the construction must be audited back to its source. The PassivHaus standard for total energy use is 60 kilowatt-hours per square meter of floor space per year. This is equal to 5.6 kWh per square foot per year. If your house has 2,500 square feet of living space then your total energy budget to meet the PassivHaus standard (including heating fuel like natural gas or heating oil, plus your electricity use) is about 14,000kWh per year. The average U.S. house uses about 11,000kWh per year in electricity alone. When you add in the extra energy used to heat the home, often five times the amount of energy used in electricity, the average U.S. house uses about 500% more energy than the PassivHaus standard.

After we installed the fab four (insulation, heat pumps, solar panels and triple-glazed windows) our house is using about 6.5 kWh per square foot per year or only about 16% more than the PassivHaus standard. This is a remarkable result given that the Passivhaus standard was created for new houses and our house is a 1970’s design with no sealing of the walls against air infiltration and with only average insulation in the walls. Zero Carbon Home and PassivHaus have similar approaches to reducing energy consumption such as better insulation, low-E triple-glazed windows, heat pumps and solar panels. But because of the prescriptive details and audit trail on building components required by PassivHaus it is almost impossible to apply it to the renovation of an existing house and it is only applicable to new construction. It is both expensive and time consuming to do the audit.

If you found this page intriguing you will almost certainly find the book, Zero Carbon Home,  helpful. It is written in an easy-to-read style backed by a rigorous scientific approach and detailed financial analysis. The book costs $20 and is available by clicking here.

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