Background

Energy use and indoor environment – equally important

The majority of the energy is used during the operation phase of a building’s life cycle and is therefore the most important to reduce. The energy use of a building depends both on the building envelope and on the building services systems which, in their turn, affect the indoor environment. Concentrating excessively on either good indoor environment or energy efficiency might cause mutually negative effects; sub-optimisations are hence important to avoid.

 

Retrofitting and energy use – no universal solutions

If we are to achieve significant reductions of energy use in existing buildings, it is important to perform future large-scale retrofitting of buildings in a systematic and controlled manner. When retrofitting a building many aspects must be taken into account, such as local resources, costs, building traditions, legislation and financing. These aspects will have an impact on decision-making and on the outcome of the retrofit, which will differ from case to case, and so there are no universal solutions.

 

A dynamic and flexible quality assurance (QA) system

However, to achieve the intended results of the retrofit requires knowledge, continuity and communication that can be assured by a dynamic and flexible quality assurance (QA) system that describes a systematic and controlled way of working in each country. The QA system should cover both retrofitting and maintenance, since experience shows that a successful energy improvement retrofit will be permanent only if use of the building is guided by effective routines and increase of competence of all parties.

 

The potential for energy efficiency improvements

Since an important part of the energy efficiency improvement potential lies in the residential building stock, the use of the QA system for retrofit improvements is justified as follows:

■	there are several million residential buildings in the European Union
■	many of these buildings were built before the oil crises of the 1970s, and therefore use unnecessarily high amounts of energy
■	the need to make up for many years of neglected maintenance means that both the building envelope and building services need to be upgraded, which provides the owners with an opportunity for cost-effective energy measures
■	the social housing stocks consist of many similar apartments the measures can easily be replicated cost-effectively