Energy Indicators for Sustainable Development: Guidelines and Methodologies International Atomic Energy Agency United Nations Department of Economic and Social Affairs International Energy Agency Eurostat European Environment Agency

(b) Measuring Methods: 
Energy Use: Energy use (including district heating and electricity) and electricity 
intensities are recorded separately. Final energy use is usually measured at the point 
of use (i.e. the building or enterprise). Data for enterprises in this sector are usually 
collected through the enterprise’s normal accounting of expenditures or use of energy. 
Note, however, that the correspondence between enterprise and building type can be 
very loose. 

---

61 
In a few countries, energy use in buildings by type of end use is measured by surveys 
of actual buildings. Where these data exist, they can be used to construct more 
disaggregated intensities that better reflect efficiencies of certain end uses. Heating 
energy use per square metre of floor area heated is an important example of such a 
measure. Electricity use per square metre is important to measure, but it is difficult to 
disaggregate into heating, cooling, water heating/cooking, lighting, etc., without 
recourse to detailed surveys. Some colder countries (e.g. Norway) have a high overall 
energy intensity in the service sector and a high share of electric heating, while other 
colder countries (e.g. Finland) also have high intensities, but with much less electric 
space heating. Similarly, warmer countries have substantial amounts of space that are 
fully air-conditioned. For many countries, data on the amount of air-conditioned space 
are not available. 
Despite all these uncertainties, fuel intensities give useful information about space- 
and water-heating and cooking activities, and electricity intensities for electricity 
services. 
Units: toe for final energy and kWh for electricity. 
Output: There are different approaches to measuring output in the service/commercial 
sector, with value added as the most direct measure of economic output. However, 
intensities calculated as energy per unit of floor area are more closely related to 
energy efficiency for end uses such as heating, cooling and lighting. Surveys of floor 
area, by building type, have been carried out in many International Energy Agency 
(IEA) Member countries. Often, the building type is specifically related to the activity 
of the enterprise — for example, school (education), hospital (health care) or 
restaurant (food services). However, in many cases, particularly for offices and 
restaurants, buildings contain a mix of activities and enterprises, each with its own 
energy system and with considerably different energy-use patterns. 
Unit: Constant currency. The market value of output in the real national currency is 
deflated to a base year using GDP deflators. The national currency can be converted 
to US dollars, using PPP for the base year. For floor area, square metres of built space 
is usually the unit, but in some colder countries, square metres of occupied or heated 
space is recorded. The difference, which can be significant, reflects unheated spaces, 
garages and stairwells, etc.