LOW-ENERGY HOUSE

Generically, a 'low-energy house' is any type of house that uses ''less energy'' than a regular house.

Contents

General usage

National standards

Beyond ultra-low energy buildings

Low energy technology

See also

External links

Examples

General usage

In general use, the meaning of the term 'low-energy house' has changed over time, and will certainly change in the future. Right now, it is generally considered to be one that uses around half of the German & Swiss low-energy standards mentioned below for space heating, typically in the range from 30 kWh/m²a to 20 kWh/m²a (8,000 Btu/ft²/yr to 6,000 Btu/ft²/yr). Below this the term 'ultra-low energy building' is often used.
Other uses, for example to mean any reduction in energy use below the standards demanded by current building codes, are also frequently encountered. Because national standards vary considerably, 'low energy' developments in one country may not meet 'normal practice' in another.

National standards

In some countries the term relates to a specific building standard. In particular these seek to limit the energy used for space heating, since in many climate zones it represents the largest energy use. Other energy use may also be regulated.
In Germany a "Low Energy House" ''(Niedrigenergiehaus)'' has a limit equivalent to 7 litres of heating oil for each square meter of room ''for space heating'' annually (50 kWh/m²a or 15,850 Btu/ft²/yr). In Switzerland the term is used in connection with the ''MINERGIE^®'' standard (42 kWh/m²a or 13,300 Btu/ft²/yr).
In comparison, the German ''Passivhaus'' ultra-low energy standard, currently undergoing adoption in some other European countries, has a maximum space heating requirement of 15 kWh/m²a or 4,755 Btu/ft²/yr.

Beyond ultra-low energy buildings

Beyond ultra-low energy buildings are those that use, on average over the course of a year, no imported energy (zero energy buildings), or even those that generate a surplus (energy plus houses), both of which are being built.
This can be achieved by a mixture of energy conservation technologies and the use of renewable energy sources. However, in the absence of recognized standards, the mix between these - and consequently the energy-use profile and environmental impact of the building - can vary significantly.
At one end of the spectrum are buildings with an ultra-low space heating requirement that therefore require low levels of imported energy, even in winter, approaching the concept of an autonomous building.
At the opposite end of the spectrum are buildings where few attempts are made to reduce the space heating requirement and which therefore use high levels of imported energy in winter. While this can be balanced by high levels of renewable energy generation throughout the year, it imposes greater demands on the traditional national energy infrastructure during the peak winter season.

Low energy technology

Low-energy buildings typically use high levels of insulation, energy efficient windows, low levels of air infiltration and heat recovery ventilation. They may also use passive solar building design techniques or active solar technologies. To reduce energy needs for domestic hot water these homes may also use hot water heat recycling technologies to recover heat from showers and dishwashers.
For further detail about the general evolution of the low energy house, see zero energy building.

See also

★

★ House Energy Rating

★ EnerGuide for Houses

★ EnerGuide for New Houses

★ Passive house

★ Superinsulation

★ Zero energy building

★ Low-carbon economy

★ VerdaTech

External links

★ Very Low Energy Houses - discussion paper - Nov 2006

★ IEA Energy Conservation in Buildings and Community Systems Programme.

★ Common Fire Foundation Comprehensive Overview of Green Building, plus info on the net zero energy "Greenest Building in the Eastern US" (non-profit)

★ MINERGIE^® (official site)

Examples

★ Minimum Energy houses in the Netherlands (1982-1983)