Green solutions for old buildings

Europe is facing a big challenge regarding the energy consumption of its housing stock given that it accounts for approximately 40 % of the total energy consumed. Although building new homes according to the demanding energy efficiency regulations is essential, it will take several decades before such houses become a significant proportion of the stock.

The major challenge is to retrofit energy-inefficient buildings to meet 21st century standards. The EU-funded project 'Holistic energy-efficient retrofitting of residential buildings' (HERB) has been initiated to develop and demonstrate new and innovative energy-efficient technologies and solutions for retrofitting older buildings. These will be installed in a number of typical residential buildings in EU countries and their performance will be monitored.

HERB is selecting and integrating the best available technologies, following a truly holistic approach. Technologies envisaged for envelope retrofitting include various types of insulation materials. Energy-efficient solutions will also be deployed, including energy-efficient lighting, heating, ventilating and air conditioning as well as renewable energy systems. The proposed solutions will be affordable, durable, easy to install, and compatible with existing building functions and aesthetics.

The types of building for retrofitting include detached, semi-detached and terrace houses, and flats of different ages. HERB will use various methods for measuring the building performance before and after retrofitting. These will be leakage tests and thermal imaging to determine the main parts of the building envelope that need to be improved. Furthermore, smart meters will be used for each technology to measure energy savings.

So far, project members have developed computer models for optimising components for each technology and each combination of technologies for retrofitting various types of buildings. Additionally, they have developed models for simulating energy demand and supply as well as the indoor environment in residential buildings.

HERB is providing a holistic approach for retrofitting homes, allowing them to achieve the energy efficiency levels of new buildings. With its proposed solutions, HERB is moving towards the goal of a low-carbon society, achieving more than a 60 % reduction in carbon dioxide emissions.