EASME

Closing the gap between promised energy savings and the real energy consumption of buildings

Closing the gap between promised energy savings and the real energy consumption of buildings

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15/12/2017

​We expect our homes, offices, and public buildings to meet the building regulations put in place by our country to save energy and protect the environment. Modifications that take place during building construction leading to divergence from the design can result in significant discrepancies in energy performance ratings. Identifying these gaps and making recommendations are at the heart of the EU funded QUALICHeCk project.

Through the Building’s Energy Performance Certificate prospective buyers and tenants are encouraged to invest in energy efficiency in buildings. Deviations between the actual versus claimed or expected energy savings could discredit the overall approach to energy conservation in the building sector and limit its benefits.

To avoid this, the QUALICHeCK project carried several field studies across the EU. In Sweden for example, the results of the field study assessing the difference between calculated and measured energy use in buildings were used in the review of the national regulations for energy performance certificates. An Estonian field study on summertime overheating requirements revealed that 68% of buildings investigated did not comply with the regulations. As a result, checks on overheating are now more widely used in the country and discussions on quality issues have progressed.

Results like these acted as a real eye-opener and led to concrete improvements in national practices. The project's knowledge has been gathered in two Source Books presenting practical recommendations to achieve compliant input data for energy performance certificates and improved quality of construction. Identified solutions include databases of pre-calculated values, standardised information on product characteristics, training programmes, and qualification and certification schemes, which are helping to pave the way towards Nearly-Zero Energy Buildings and a better implementation of the Energy Performance of Buildings Directive in several countries.

Collaborative exchange amongst Europe-based organisations working on these topics takes place on the QUALICHeCK platform.

Key findings in a nutshell:

  • modifications between design and construction are frequent, which can lead to significant discrepancies in energy performance ratings if there is no explicit national requirement that calculations be consistent with as-built characteristics;
  • non-compliant product selection or implementation compared to building work specifications are frequent, notably for ductwork airtightness, due to the lack of skills, economic conditions, or lack of control during the construction process, this being detrimental to the quality of the final building;
  • the significant deviations between claimed and actual energy performance, which can be over 50%, suggest that the national compliance frameworks for construction quality and calculation input data, as implemented today in some EU countries are not dissuasive enough, whilst occupant behaviour also has an impact on the energy consumption.

Image: Shutterstock / Ant Clausen

Useful links:

 Field Studies in Member States

Full report