Definitions of a Low Energy House

At present a low energy house is practicable without insulation systems. Passive houses are also starting to become more common. Passive houses are also just an interim phase, as it is possible to build houses who net energy consumption is zero, or even houses that produce more energy than they consume.

In comparing definitions of kW readings it is worth noting that such readings are calculatory and describe the heating energy needs in a normal year.

Low energy house

According to the commonly used loose definition, a low energy house consumes half the heating energy than a house that fulfils current building regulations.

According to Ministry of Environment guidelines, in planning a low energy house the building’s calculated heat loss must be at maximum 60% of the comparative heat loss in building regulations. By designing a house on this principle and by taking into account free heat loads, overall energy consumption can be halved.

A low energy house consumes less than 60 kw/ brm² a year in South Finland, and under 90 kW/ brm² a year in North Finland.
 

Passive energy house

A passive energy house does not, according to the usual definition, need any heating or cooling energy. In the Finnish climate the level of cost effectiveness has yet to be reached where no heating is required at all. According to the Technical Research Centre of Finland’s definition, a passive house in South Finland requires 20 kW/brm² a year and 30 kW/ brm² in North Finland.
 

Zero energy house and plus energy house

A zero energy house produces at least the same amount of renewable energy than the non-renewable energy it consumes. Plus energy produces more annually than it consumes.

Page last updated 5.8.2011

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