What are the passive house requirements for windows?

VELUX PassivHaus Centre-PivotCustomers who are involved in a passive house build often get in touch to ask us “what are the passive house requirements for windows?” Originating from Germany and growing in popularity across Europe, passive house (also known as Passivhaus) is a design system which can yield huge energy savings.

The Passivhaus Trust is encouraging local authorities to adopt the standard in new developments. More architects are also starting to become certified in passive house design in the UK.

Passive house requirements for windows

In general, passive house windows need to be twice as efficient as conventional windows. They must also be positioned to receive the most natural sunlight all year round. Passive house standards demand that windows are typically at least triple glazed and use metal spacers with low conductivity.

One of the most important facets is the window’s ‘U-value’. The U-value measures how well heat is transferred in or out of a building. The certified passive house standards state that U-values for windows should be below 0.8 W/(m²K).

How passive house windows prevent heat transfer

The glazing used in passive house windows is high-performance technology which harvests maximum solar gain, particularly during winter months when it’s needed most. We call this ‘thermal glazing’. Manufacturers use materials such as argon or krypton to prevent heat transfer.

What are the passive house requirements for windows certification standards?

Quad glazed windowsThe VELUX PassivHaus range includes quad-glazed windows. These are also solar-powered, meaning that the solar cell charges the window itself.

Rain sensors are another consideration. Do you want windows which automatically shut when the weather changes? You can control this functionality remotely using a VELUX INTEGRA Control Pad with a range of ventilation options. When occupants are on holiday, there are also ‘open and shut’ programs to deter thieves.

You can open and close windows in a passive house building, despite the misconception that it will affect the building’s energy efficiency. In fact, many UK studies have concluded that opening and closing windows regularly is beneficial.

Energy savings using passive house windows

Passive house systems are most commonly used in new developments. However, you may choose to retrofit an existing property with passive house techniques. This can still result in up to 75% energy savings. Contractors can replace roof windows in as little as half a day’s work. All of the work can all take place from inside of the room. Disruption is kept to a minimum because scaffolding is not needed.

A passive house gathers energy from sunlight and the heat generated by household appliances. Buildings also harness heat energy from the people living within it. Heat is then deployed and reused around the building. You can use a ventilation system to filter fresh air into the building.

For expert advice concerning passive house requirements for windows, call our team now on 01752 692 206.