4 Physical quality of the residential building stock
4.2 Energy Use
There is no European source giving consistent data on the breakdown of the energy consumption by end use, except for the Database Odysee which is not freely accessi-ble (http://www.odyssee-indicators.org/). In this section an overview of the data available in each country is given. The type of data available may differ greatly by country. For Austria, Sweden and Switzerland, there is no more specific information than given in Section 2.4.
Finland
The residential sector is responsible for 11% of total Finnish gas consumption, 20%
of biomass (coal and turf) and coal consumption, 22% of light oil consumption, 5%
Table 4.1: Basic quality of the residential building stock
of heavy oil consumption and accounts for 38% of the use of district heating. A de-tailed breakdown of energy sources for space heating and hot tap water is available from the Ekorem report for terraced houses, detached houses and apartments and is given in Figure 4.1.
Sources of heat in the Finnish residential building stock
0 5000 10000 15000 20000 25000 30000 35000
Row houses Detached houses Apartments
GWh/year
Solid fuels
Oil
District heating
Electricity for heating
Electricity for non heating appliances
* Ekorem report, 2005
The Ekorem report also gives data on the average heat losses through each building component of an average dwelling. These data are calculated based on estimates of the average heat transfer coefficient of the building components considered. In gen-eral, walls and ventilation are responsible for the main losses.
Heat losses in the Finnish residential building stock
0 5000 10000 15000 20000 25000
Row houses Detached houses Apartments
GWh/year
Floors Roofs Walls Window s Doors
Ventilation-infiltration air
* Ekorem report, 2005
Figure 4.1: Sources of heat in Fin-nish terraced houses, detached houses and apartments*
Figure 4.2: Heat losses in average Finnish building components*
France
A breakdown of the energy consumption by type and age of building is available at the level of the entire building stock (Figure 4.3) and at the level of an average build-ing (Figure 4.4). On average, a post-1975 sbuild-ingle-family dwellbuild-ing consumes 11% less energy than a pre-1975 dwelling. For multi-family dwellings, this figure amounts to 16%.
Total energy consumption in the French residential sector
0 100 200 300 400 500 600
TWh/year
Multif-amily dwellings post-1975
Multi-family dwellings pre-1975
Single-family dwellings post-1975
Single-family dwellings pre-1975
*from “Les Chiffres clés du bâtiment, Energie – Environnement”, édition 2006, ADEME.
Yearly energy consumption of average French dwellings
0 10000 20000 30000 40000 50000 60000 70000 80000
kWh/year
Multi-family dwellings post-1975
Multi-family dwellings pre-1975
Single-family dwellings post-1975
Single-family dwellings pre-1975
Figure 4.3: Total energy consump-tion in the French residential sec-tor: breakdown by dwelling type and age*
Figure 4.4: Energy consumption of average French dwellings: break-down by dwelling type and age*
* from “Les Chiffres clés du bâtiment, Energie – Environnement”, édition 2006, ADEME.
The breakdown of the average energy consumption in dwellings by space heating, domestic hot water and cooking is also available and shown in Figure 4.5. The breakdown is similar to the European breakdown given in Figure 2.11, except that space heating has a larger share in France than in Europe (65% instead of 57%) and domestic hot water a lower share (12% instead of 25%). Specific data for each type of dwelling can be found in Appendix D, Figure D.1.
Average energy consumption in dwellings (19225 kWh/year per dwelling)
Space heating 65%
Domestic hot water
12%
Cooking 7%
Others 16%
Space heating Domestic hot water Cooking
Others
* from “Les Chiffres clés du bâtiment, Energie – Environnement”, édition 2006, ADEME.
Germany
An estimate of the breakdown of energy consumption by type of fuel for single-family and multi-single-family dwellings is made based on calculations of the IWU, see Fig-ure 4.6. In multi-family dwellings, district heating replaces half the oil consumption, which is still very large in single-family dwellings. The importance of all renewable energies for heating is, however, steadily growing. The percentage of the supplied en-ergy for heating increased from 3.9% in 2000 to 6% in 2006 (BMU 2007). Owner-occupied dwellings might be the most advanced sector. From this renewable energy, 69% is biogenic solid combustibles, 3.7% solar thermal and 2% geothermic.
The Netherlands
In the Netherlands, a breakdown of the primary energy use by building type is avail-able from KWR (2000) and related publications from VROM. In a Dutch dwelling 3100 kWh electricity is consumed on average. The electricity use of Dutch house-holds varies a lot depending on the incomes of the household. The average values shown in Figure 4.7 may be 20% lower for low income households and 20% higher for high income households. The average gas use is 2000 m3 per dwelling when cen-tral heating is present and 1600 m3 when only local heating is installed. Detached houses have a gas consumption that is almost twice the consumption of apartments.
Figure 4.5: Energy consumption of average French dwellings: breakdown by end use*
Single-fam ily dw ellings
Primary energy use in Dutch dwellings
0
MJ primary energy Gas consumption (central
heating)
Gas consumption (local heating)
Electricity
* from Basisrapportage Kwalitatieve Woningregistratie 2000, VROM
In the KWR, an energy indicator is used to indicate the energy efficiency of the dwelling. The value of this energy indicator, a figure between 0 (low quality) and 5 (high), depends on the number and type of insulation measures and the heating sys-tem. The relationship between gas consumption and energy indicator is shown in Appendix D, Figure D.2.
Figure 4.6: Energy consumption of single-family and multi-family German dwellings: breakdown by type of fuel*
Figure 4.7: Final energy consump-tion in Dutch dwellings: break-down by type of building*
United Kingdom
In the UK, 82% of energy used by households is for space or water heating (see Fig-ure 4.8). Since 1970, energy use for space heating has risen by 24%, for water heating by 15%, and for lighting and appliances by 157%. In contrast, energy use for cooking has fallen by 16%. The individual countries within the UK have wide disparities in the mix of fuels used in the domestic sector. Northern Ireland uses more coal and oil, since gas has only recently been introduced, while Scotland consumes more elec-tricity. This comes from the higher proportion of flats in cities in Scotland, which of-ten use electrical heating instead of gas or oil driven systems. Central heating is based on gas for 71% and on solid fuels for only 3%. Electrical storage heating accounts for 9%.
There is also data available on the effect of insulation and more efficient heating sys-tems on the energy use for space heating (see Figure 4.9). Without insulation, energy consumption would have been 59% higher by 2000 compared to 1970. Without insu-lation and more efficient heating systems the energy consumption would have been 110% higher.
*Graph from Energy Consumption in the UK, DTI.
Figure 4.8: Evolution of the final energy consumption in dwellings in the UK: breakdown by end use*
* Graph from Energy Consumption in the UK, DTI.