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Concepts and definitions

Ambient energy

Ambient energy refers to energy extracted with heat pumps from the environment (ground, air or water) for space heating. Ambient energy is the difference between the heat produced by heat pumps and the electricity they consume. Electricity used by heat pumps in cooling use, as well as electricity used by heat pumps in heating use, are in this examination included in electricity consumption of heating.

Coefficient for specific annual consumption

In these statistics, the coefficient for specific annual consumption describes the consumption of different energy sources per cubic metre built (kWh/m3).

Consumption of heating energy in spaces

Consumption of heating energy in spaces comprises the consumption of fuels, electricity, district heating, and ambient energy. Heating energy comprises the energy of the main heating system and those of other forms of supplementary heating, inclusive of devices associated with ventilation and heat distribution. In these statistics, supplementary heating is referred to as additional heating. Some of the electricity used by housing companies in residential properties has also been allocated to heating and ventilation systems. Consumption includes energy sources bought or otherwise acquired for housing (e.g. wood fuel produced for own use) and losses from the use of fuels (e.g. boiler losses).

Cubic capacity of residential buildings

For buildings completed after the beginning of 1980, data on cubic capacity of residential buildings are available from a register. For buildings completed prior to this, missing data on cubic capacity are imputed by means of data available from the building stock on floor area and cubic capacity by purpose of use and year of construction.

Energy consumption in households

Includes consumption of energy needed for heating spaces in residential buildings and domestic water, and electricity used for household appliances. The use of natural gas and liquid gas in cooking as well as the use of wood and electricity for heating saunas are also included. Energy consumption of the means of transport (incl. private cars) used by households is not included in energy consumption in households but in energy consumption of transport.

Energy consumption of cooking

Calculations of energy consumption of cooking take into consideration stoves and ovens. The main energy source used in cooking is electricity, to some degree town gas and liquid gas, wood and charcoal. The use of wood and charcoal is estimated to be marginal and they are excluded from these statistics.

Energy consumption of domestic water heating

Energy consumption of domestic water heating comprises the energy used for heating water. The majority of residential buildings in Finland have central heating system by water circulation in which case water is heated with the same main energy source. Major dry heating systems are direct electrical heating, stove heating and air circulation central heating. In these systems, water is usually heated using a separate electrical storage boiler (hot water tank).

Energy consumption of electrical equipment

Energy consumption of electrical equipment comprises the energy used by pieces of electrical equipment in dwellings and real estate properties. Electrical equipment include e.g. microwave ovens, coffee makers and kettles, refrigeration equipment, washing machines, tumble dryers, televisions and computers with their accessories, cellar cooling systems, lifts and vehicle engine block and interior heating. Electrical sauna stoves and equipment related to heat distribution and ventilation are included in electricity consumption of heating.

Energy consumption of household appliances

Energy consumption of household appliances comprises the energy used for electrical appliances, lighting and cooking.

Energy consumption of lighting

Energy consumption of lighting comprises the energy used for lighting residential buildings and their surrounding grounds. Some of the electricity used by housing companies in residential buildings is also used for lighting common areas. The energy source for lighting covered by this examination is electricity; the share of other energy sources is assumed to be marginal.

Energy consumption of sauna heating

Energy consumption of sauna heating comprises the energy used for heating sauna stoves. Sauna stoves are usually heated with wood or electricity. In addition to detached house and apartment-specific saunas, the consumption also covers building-specific saunas in blocks of flats and wood-heated saunas in free-time residences.

Energy sources / heat sources

Energy sources for residential buildings comprise fuels, electricity, district heat and ambient energy. Electricity includes grid electricity only; self-produced electricity in the form of e.g. solar or wind power is left outside this examination for the time being.

Floor area of residential buildings

The floor area of residential buildings is obtained as gross floor area from the building stock. Gross floor area is the combined floor area of the storeys of buildings. Gross floor area includes the floor area of each storey up to the external surfaces of exterior walls.

Fuels

Fuels used as energy sources for residential buildings here include wood, peat, coal, light fuel oil, heavy fuel oil, natural gas and liquid gas.

Ground heat

Ground heat comprises the heat extracted from a bored well and collection pipework. Heat extracted from water bodies is also included in ground heat in this examination. The electricity consumed by ground heat pumps is not included in ground heat but in electricity consumption of heating.

Heating degree day (HDD)

Figures describing the annual heating requirement in different localities have been calculated for indoor temperature of 17°C assuming that heating is stopped in spring when outdoor temperature rises above 10°C and started in autumn when it falls below 12°C. Figures for heating degree days are produced by the Finnish Meteorological Institute. These statistics have been compiled by using the heating degree day figure for Jyväskylä to describe the average heating requirement for the whole of Finland.

Housing

In these statistics, housing refers to energy consumption in households. Housing covers residential buildings in housing use inclusive of their saunas and surrounding yards. For surrounding yards, the examination includes electrical equipment only i.e. outdoor lighting and car/block heaters.

Net effective heating energy

Net effective heating energy is the part of energy acquired for a residential building that can be exploited in heating. Some of the acquired energy is wasted due to fuel conversion and transmission losses. Bet effective heating energy has been calculated by deducting heating system losses from the amount of energy used for heating of spaces. District and electric heating are net effective heating energy as such. Net effective heating energy of heat pumps has been calculated as the sum of produced ambient heat and consumed electricity. The following assumed net effective heating energy ratios have been used for other energy sources:

• Small combustion of wood 55%
• Peat 60%
• Coal 60%
• Heavy fuel oil 83%
• Light fuel oil 78%
• Natural gas 90%

The assumed net effective heating energy ratios are based on the REM model (model for calculating energy consumption for the building stock) jointly developed by the Tampere University of Technology and the Technical Research Centre of Finland.

Residential building

In these statistics, residential buildings refer to the main categories of Residential buildings (A) and Free-time residential buildings (B) in Statistics Finland's classification of buildings. These are divided into the following sub-categories:

• detached houses: one and two-dwelling houses, semi-detached houses and other detached and semi-detached houses.
• terraced houses: rowhouses, terraced houses and other attached houses
• blocks of flats: balcony-access blocks and houses with at least three dwellings of which at least two are on top of each other.
• free-time residential buildings: detached summer cottages or free-time residences mainly intended for private use.

Unit specific consumption

Unit specific consumption refers to the average annual consumption of a certain equipment group. When it is multiplied by the number of pieces of equipment, the total annual consumption of the equipment group is obtained.

Unoccupied residential building

In this examination, a residential building is unoccupied if it contains no permanently occupied dwelling units according to register data.