5 examples of how to reduce buildings’ energy consumption

State of Green
By State of Green, February 19, 2019

Buildings are one of society’s greatest energy consumers, accounting for almost 40 per cent of global energy consumption and 36 per cent of CO2 emissions.

According to the Danish Energy Agency, approximately 85 per cent of the buildings we will live in by 2050 already exist today. Therefore, if we want to achieve carbon neutrality, it is of key importance that we take steps to improve the energy performance of already existing buildings. Retrofitting brings a range of benefits such as improving the indoor climate, reducing CO2 emissions and is beneficial to the economy.

Therefore, we’ve put together 5 examples of how to effectively reduce buildings’ share of energy consumption.

1. Improving the air quality to enhance educational outcomes in Aarhus, Denmark

Recent research in Danish schools shows that in more than 50 per cent of cases, the air quality does not meet minimum standards. This affects students’ learning ability and concentration. In comparison to adults, a bad indoor environment is more critical for children, as they are still developing. In fact, children can miss the equivalent of one educational year due to a poor indoor climate.

A holistic approach to the renovation of a school in Solbjerg in Aarhus increased the air change rate using natural ventilation through new façade modules, which created added benefits by improving the indoor climate. The natural ventilation air intake is located in the upper part of the façade modules. The air is then supplied through the entire area of the newly installed permeable ceiling, creating draught free conditions in the classrooms.

2. Making a positive impact on public health in Anderlechtois, Brussels

Due to the increasing age of the European building stock, unhealthy buildings have become a public health issue. These unhealthy buildings do not only affect inhabitants physically, but also have an impact on the general economy. However, if just 2 per cent of European homes were renovated every year, by 2050 we could reduce the number of Europeans who live in an unhealthy home by 50 per cent.

RenovActive House is a single-family house constructed by the public housing company Foyer Anderlechtois in Brussels. In 2016, the house was renovated based on the concept of “Climate Renovation”, which aims to create a first-rate indoor climate and good energy performance. The social housing projects concept consists of seven different elements. Each element supports specific properties that improve ventilation, strengthen the climate envelope and expand the living space through densification or extension. The RenovActive project in Belgium proves that by exploiting a renovation concept that can be adapted to even the strictest of budgets, it is possible to solve one of the biggest health issues in European society

-Related solution: Sustainable building designed to leed platinum

3. Retrofitting a world heritage listed museum in Melbourne, Australia to reduce CO2

Museums Victoria in Melbourne attracts approximately 2.5 million visitors each year, and its six locations have recently been upgraded for a more climate friendly future. The Victorian Government’s Greener Government Buildings program selected global engineering company Siemens to bring state of the art energy and environmental efficiency technology to Melbourne Museum, the World-Heritage listed Royal Exhibition Building, Scienceworks, the Immigration Museum and two storage facilities. The project comprises of a total upgrade of the building management, lighting, water and cooling systems.

The success of the modernisation concept is already tangible: CO2 emissions have been reduced by 35 per cent. Siemens anticipates a savings of 4,590 tons of CO2 by the end of the contract term. Water consumption has dropped by six per cent. The utility costs have been reduced by 32 per cent, an amount equivalent to the electricity consumption of 1,264 average households.

4. Ensuring worshippers stay warm in Copenhagen’s synagogue without increasing the energy bill

The synagogue in Copenhagen was built in 1833 and is a listed building after being deemed worthy of preservation by the Danish Ministry of Culture. The building is used several times a day for religious gatherings, lectures and especially during the Jewish Sabbath each Saturday. An effective heating system is required in a cold climate like the Danish one, but as the synagogue is almost 180 years old, the insulation level and structure do not enable a warm indoor climate. To heat all of the building’s  1225 square metres without increasing energy consumption, an energy reduction project was needed. Architects and engineers from Rambøll initiated the renovation project of the old synagogue, which is constrained by the obligation to maintain original architectural, cultural and environmental aspects due to its heritage-listed status.

The renovation process included the addition of adequate roof insulation, installation of removable windows with energy measures, a new heat-distribution installation, ventilation system and, lastly, a replacement of existing light sources with LED lighting. The new heat installation enables energy savings through various measures, such as ensuring capacity equals the heating demand – thereby alleviating the need to supplement demand with expensive electrical heating. The energy reductions will make a positive impact on operational costs and potentially reduce CO2 emissions at the same time. The old synagogue can expect to reduce annual energy costs by EUR 16,000, and simultaneously ensure an energy efficient building with a warm and comfortable indoor climate for the users.

5. Grassroots energy renovations in Middelfart, Denmark

Middelfart municipality is located on the Island of Fyn in Denmark. Here, multiple initiatives have been launched in order to increase energy efficiency in both public and privately owned buildings. The keywords in the initiatives are awareness and mobilising citizens as the main driver for changes, which will have a tangible impact on the path to a climate-neutral future.

The municipality is the first to introduce “Building Analytics” based upon a co-operation with Schneider Electric. The approach, using big data and analyses, bridges the gap between analyses of buildings’ performance and decision-making. The tool gives an overview at two levels: First, it demonstrates which actions could be initiated from a cost perspective and secondly, it is possible to get a prioritised list of actions if building operations take health and comfort perspectives into account. Parameters such as humidity, CO2 concentration, and temperature are prioritised, whilst optimising building performance by an average of 7 per cent.

Instead of traditional energy saving campaigns, the municipality of Middelfart and a local evening school started the “Evening School” based on non-formal adult education. The theme was retrofitting and renewable energy options for homes. Homeowners paid a small amount to participate and local engineers and companies contributed as teachers in the modules. The evaluation showed that the participating citizens had made investments amounting to almost EUR 268,000, showing the importance of knowledge sharing for increased investments in renovation.


For more information read the white paper Energy renovation of buildings here.

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