For the residential sector,5) energy consumption has been linked at the micro level to addresses of residential buildings, allowing analysis of energy consumption by building type, size and construction period. For the services sector, energy consumption statistics were only available by economic sector. The pilot study took the statistics on energy consumption in the services sector one step further by assigning gas and electricity consumption of services to buildings, allowing the analysis of gas and electricity consumption per m2 floor area by economic (sub)sector and by building type, size and construction period.
Matching data of gas and electricity deliveries in the services sector to buildings and subsequent floor areas is complicated. Companies often do not occupy just a single address and they often have more than one gas and/or electricity connection. The term ‘building complex’ has therefore been introduced to define one or more than one unique address occupied by a single company served by one or more than one gas and electricity connection. Examples of building complexes are described below:
— A company occupying a single building consisting of one unique address (for example a grocery store). This is the simplest case for which linking the energy consumption to floor area is rather straightforward.
— A company occupying a whole building consisting of multiple addresses (for example an apartment hotel). In such cases matching the energy consumption to floor area depends on the identification of which addresses belong together. Such information is available for most buildings.
— A company occupying only part of a building (for example a single shop in a shopping mall). In such cases other companies may occupy other parts of the building,
complicating identification of the floor area occupied by the company and the gas and electricity connections belonging to it.
— A company occupying several buildings that belong together (for example a university or a hospital). In such a case matching the energy consumption to floor area depends on the identification of which buildings belong together. This information is not always available.
In the pilot study a methodology has been developed to assign gas and electricity deliveries to ’building complexes’. Due to the complications discussed above, sometimes only a part of a building complex can be identified. In such cases the energy efficiency indicator is overestimated. In other cases none or not all energy connections belonging to a building complex can be defined. In those cases the energy efficiency indicator is underestimated. To exclude such cases in the analysis we developed a set of validation rules and plausibility checks at the micro level.
The methodology developed in the pilot study has been applied to data of the client registers matched to building registers of the year 2013. Building complexes were identified, including the energy connections belonging to the building complex. These connections have unique identification numbers. Data on gas and electricity deliveries of other years can be matched on the basis of these energy connection identification numbers. In the pilot study we developed a methodology to determine whether the building complex was still occupied by the same economic activity in different years, taking into account the effect of methodological improvements on assigning economic activities. Indicator E is only calculated for building complexes with the same economic activity across the years and with validated gas and electricity rates per m2 across all years. Contrary to indicators B-D, the methodological improvements discussed earlier have only a limited effect on the consistency of trends between 2010–2013 for indicator E.
However, the results are only representative for building complexes in the services sector throughout 2010–2013. The indicator does not take the effects of new buildings constructed after 2010 into account nor the effects of demolitions before 2014. The indicator is also not representative for companies housed in buildings with energy connections that are shared by different companies. One example is an office building that houses several companies with different economic activities. These companies rent the office space from a real estate company which manages the building infrastructure including energy. In such cases it is impossible to determine the share of gas and electricity consumed by the different companies.
In general the quality of the indicator is considered high for simple building complexes, i.e. building complexes occupied by one company consisting of a single address (for example primary schools and shops). The quality of the indicator decreases for building complexes that are part of a larger building (offices) and building complexes consisting of several distinct buildings (for example universities and hospitals).
Building types (for example primary schools, secondary schools, supermarkets, shops, etc.) have been developed together with energy institutes in the Netherlands (ECN and EIB). The building types are often an aggregation of more detailed classes in the economic activities classification (SIC 2008). The indicators (average temperature corrected gas consumption in m3 per m2 floor area and average electricity consumption in kWh per m2 floor area) are therefore available at a more detailed level than economic sectors. For instance for sector P (SIC 2008), the indicator is estimated for the building
types primary education, secondary education and tertiary education. Like for indicator D, it is impossible to estimate the total energy consumption at disaggregated level.6)