FAQ

How much of the world’s energy is consumed by buildings?

Buildings represent 32% of total final energy consumption. In terms of primary energy consumption, buildings represent around 40% in most IEA countries.

What does primary energy consumption mean?

Primary energy consumption refers to the direct use of energy at the source, or supplying users with crude energy which has not been subjected to any conversion or transformation process.

What does final energy consumption mean?

Final energy consumption refers to energy that is supplied to the consumer for all final energy uses such as heating, cooling and lighting.

How much energy do electronics and computers consume in buildings?

Consumer electronics and computer equipment now represent 15 percent of global residential electricity consumption. It is estimated that the energy used by these devices will triple by 2030 unless actions are taken to increase energy efficiency.

What are the main policies to reduce energy demand in the buildings sector?

There are three types of policies that address energy consumption in buildings:

• Regulatory instruments: The main regulatory instrument is the building energy code, which is a set of minimum energy performance requirements. The purpose of the energy code is to ensure that a building’s energy performance is considered during the design stage of a building project. (Building energy codes are mandatory in the European Union and often voluntary in other countries). Energy requirements can be set in different ways and the basic types are:
  • Prescriptive: energy requirements are set for each building component (windows, walls, roofs) as well as heating, ventilation and air conditioning and lighting equipment.
  • Trade-off: Although energy requirements are set for each building component, a trade-off can also be made. For example, a building might balance its energy requirements by having a stringent requirement for insulation and a lower requirement for its lighting.
  • Model building: General reference calculations are made for different types of buildings such as hospitals and multi-family buildings. For any new building, a calculation is made to demonstrate that it will be as good as the reference calculation.
  • Energy frame: An overall framework establishes the energy requirements for a building, including set levels for maximum amount of energy that can be lost because of the way a building is constructed. A calculation of the building has to show that the building will not exceed the maximum allowed loss of energy.
  • Performance: Energy requirements are based on a building’s overall primary energy consumption. A maximum allowed primary energy consumption is given for each climate zone and building type. A calculation of the building has to show that the building will not exceed the maximum allowed consumption of primary energy.
• Information instruments: Labels are the best known information policy tool used for both appliances and buildings. There are two main types of labels:
  • Endorsement labels: They are voluntary and provide easy to understand but limited information. Their voluntary nature means that there is no enforcement mechanism.
  • Information labels: They help increase understanding of energy efficiency by providing detailed information. However, they require a strong campaign to avoid misinterpretation of the information. They also need to be regularly updated to be aligned with technology developments and require enforcement mechanisms. (Information labels are implemented either on a voluntary or mandatory basis).
• Incentive schemes: They are complementary policies to regulatory and information instruments used to help increase interest in energy efficiency investments. They include all policy instruments that relate to fiscal, financial and other economic incentives and disincentives to deliver energy efficiency improvements. Their objective is to motivate consumers to pursue investments they would not have ordinarily considered.

What does S&L stand for?

• Standard (Minimum Energy Performance Requirements, MEPs)
• Labels

This abbreviation is mainly used for appliances, lighting and equipment and very rarely for buildings.

What is an Energy Performance Certificate?

It is the European mandatory energy label for buildings.

What does Zero Energy Building (ZEB) mean?

Although this is not yet a standardised definition, there is a common agreement on the fact that a Zero Energy Building should refer to a building with very low energy demand, and that the energy consumed is primarily supplied by renewable sources.

Can Zero Energy Buildings be built in any climate and for any type of building?

Yes. New buildings can be designed from the outset as Zero Energy Buildings. This involves assessing how the building will integrate into its environment. (For example, if a building is near a mountain, this will determine where the windows are placed to ensure maximum exposure to sunlight in cold climate). The process also involves working on the design and overall shell (roofs, walls, windows) of the building. The last step is to use the most efficient appliances and equipment. For existing buildings, it’s not always possible to reach Zero Energy demand. However, each time a building is retrofitted, it is necessary to adopt a holistic approach and start with the shell to ensure every part of the building is considered so that the maximum energy savings potential is realised.

What does passive house mean?

Passive house is a widely used German voluntary label. It was originally only used for residential buildings but it is now increasingly also used for non-residential buildings. The definition of a passive house is based on its energy need for heating and cooling. The building’s total energy need is given as an absolute value of its primary energy consumption as follows for different climate zones: For all climates, the building’s air leakage coefficient must be below 0.6 l/h at 50 Pa