Many countries have introduced carbon reduction targets as part of the global effort to tackle climate change. Old buildings use a lot of energy, making them a major source of carbon emissions, as well as being uncomfortable and expensive to live in. However, refurbishment works and improvements (often called retrofitting) aimed at greater energy efficiency are costly and time-consuming. For non-profit social landlords that often have several hundred homes to tackle, the problem seems unsolvable.

The programme is particularly focused on social housing, which in many countries makes up a considerable proportion of the building stock and is often old and in need of renovation. Large housing providers face the challenge of decarbonising their housing stock in accordance with national regulations or their own targets. This has been exacerbated by the energy crisis in Europe, which has driven a large part of the population into fuel poverty.

The approach was initially developed in the Netherlands, where there is a large stock of post-World War II social housing. It has been adapted and implemented in other countries, such as the UK, France, Germany, Italy and the USA, where there is also a need for large-scale building retrofits and continues to attract interest from other countries.

Objectives

To future proof our lives, we must change how we live, what we eat, what we buy, how we move around and how we develop ourselves. GEA focuses on some of these challenges and translates them into the following programme streams:

• Boost the energy transition market for our homes and communities so we no longer use fossil fuels.
• Push forward the development of energy-positive materials when we build or renovate buildings.
• Inspire and facilitate personal and business developments that make change possible. 4. Push forward and map the right regulations and financing schemes needed to bring about change.

The Netherlands-based Global Energiesprong Alliance (GEA) is the umbrella body that coordinates the approach. Individual ‘market development teams’ work in the countries that are carrying out Energiesprong retrofits, including the UK, France, Germany, Italy, the USA and Canada.

These teams work with government agencies and financial institutions to create policies that support large-scale building retrofits. They coordinate housing organisations, construction companies and technology manufacturers to launch pilot projects and then broker retrofit deals involving thousands of homes.

GEA has always worked ‘open source’ to help kick-start the retrofit market. This means everything it does and creates is freely available to the public, so anyone can access it without paying or applying for usage rights. This approach helps to drive the retrofit movement internationally and encourages technological innovation in the industry.

Buildings undergoing an Energiesprong retrofit are measured very precisely. This is so insulated roof panels and wall façades pre-fitted with high-performance windows can be made off-site. The benefit of prefabricating these and other building components is that it creates a standardised product that can be manufactured in large quantities. This improves quality, reduces costs and allows retrofits to be completed on-site in as little as 10 days.

Reducing reliance on fossil fuels is a big part of Energiesprong’s approach and renewable energy sources, like solar panels, are included in its retrofits. Other technologies include smart and highly energy-efficient heating and cooling systems.

Residents are involved in every part of the process, attending community meetings and workshops, where they learn the benefits of an Energiesprong retrofit. They have a say in decision making to ensure the refurbishment meets their specific needs and creates comfortable homes that are easy to live in. They are also offered the choice to include extra elements in the project, such as a garden, or to renovate a park to benefit the whole neighborhood. Once work begins on-site, the speed of the process means there is very little disruption to tenants’ lives. When the retrofit is finished, residents provide feedback through surveys and interviews. This information is then used by GEA to refine the Energiesprong approach.

GEA uses performance-based contracts for the works. This incentivises construction companies and manufacturers to carry out high-quality work that achieves the required energy savings and that these benefits are maintained over time. Tenants are trained to manage any new appliances while monitoring systems allow them to see how much energy they are using in real time.

GEA is a non-profit organisation and has an annual turnover of around €200,000 ($217,500 USD). This is allocated to international collaboration and support of new markets (40%), knowledge exchange (20%), marketing (25%) and administration, back office and software (15%). Funding mainly comes from the EU projects that GEA is part of, including Horizon 2020, Interreg NWE and the LIFE programme.

A small amount of funding comes from annual contributions paid by Energiesprong market development teams. The teams themselves are independent and are funded by public authorities in each country. This funding ranges between €500,000 to €2,500,000 ($544,000 to $2,700,000 USD).

One of GEA’s main aims is to make retrofit projects more cost-effective and, despite the rising price of materials and labour, the total cost of retrofit projects will come down soon. This is due to the growing market for renewable energy that Energiesprong is helping to drive.

The cost of an Energiesprong retrofit per unit varies from country to country and depends on the type of building and previous works. The average cost is between €60,000 ($65,000 USD) and €100,000 ($108,300 USD) per home. Housing providers fund the works with their own money and sometimes receive funding or subsidies from national decarbonisation schemes or from the EU. Their investment is returned through the guaranteed long-term energy and maintenance savings that result from the retrofit.

In some of the pilot projects, housing providers asked residents to contribute towards the costs. This contribution was calculated in a way that still resulted in significantly lower monthly costs for residents, who benefitted from a 70-80% reduction on their utility service bills.

By retrofitting existing social housing with energy-efficient technologies, the programme aims to improve residents' living conditions, lower energy bills and reduce carbon emissions – thus achieving a social, financial and environmental impact.

Financial impact

To date, the Energiesprong programme has retrofitted more than 10,000 buildings across Europe and North America. These retrofits have resulted in a 70% to 80% reduction in energy consumption and carbon emissions, with many buildings achieving ‘net –zero' energy performance. This means they produce enough renewable energy to meet their own annual energy consumption requirements. Reduced energy consumption translates into lower energy bills for residents, improving their economic circumstances and helping to tackle fuel poverty. The Energiesprong approach has created a market for prefabricated retrofit components and has led to the establishment of several companies (such as pre.formance, Ecoworks, Renowate, Factory Zero, Synerpod).

Social impact

Energiesprong retrofits reduce a building’s energy consumption by 70-80%. This improves the comfort of tenants’ homes and lowers their energy bills. This is particularly important in Europe, where more people are being driven into fuel poverty because of the energy crisis caused by the war in Ukraine.

GEA wants to eliminate the use of fossil fuels to power buildings and many of its 10,000 retrofits to date have achieved ‘net-zero’ energy performance. This means all the energy the building needs is generated by renewable sources on-site.

Internationally, the market development teams have strengthened government support for large-scale whole-building retrofits. This includes the introduction of subsidies and tax incentives in several countries as well as specific decarbonisation funds and competitions to lower the cost of energy efficient retrofits.

Environmental impact

The construction industry and the energy-inefficiency of old buildings are both major sources of carbon emissions, which cause global warming. Renovating old buildings, rather than constructing new ones, dramatically reduces the amount of carbon released into the atmosphere. Using renewable energy sources, such as solar panels, to power refurbished buildings also lowers emissions and reduces reliance on fossil fuels, like oil, which are burned to generate electricity.

GEA is committed to sustainable construction and the Energiesprong approach reuses and repurposes materials, rather than demolishing and discarding them. Prefabricating building components off-site also decreases construction waste.

The alliance wants to increase the use of ‘bio-based’ construction materials and is embarking on a three-year pilot that will use building components made from straw, wood, bio polymer and miscanthus grass, to retrofit 88 social homes across five countries.

Reducing water usage is not yet part of the Energiesprong approach but GEA plans to introduce a water-saving component in countries where water scarcity is a serious issue.

The approach has won the following recognition:

• World Green Building Council Award (2018)
• European Commission’s award for most innovative project (2019)
• Ashden Award (2019)
• At EU level, Energiesprong has been recognised as a best practice example of energy-efficient building retrofit and has influenced the development of the EU's Renovation Wave. • At international level, it has been described as promising good-practice by climate scientists of IPCC in their 2022 report-III on solutions to mitigate climate-change (page 1565).

One of the biggest challenges facing social housing providers across the world is the need to improve the energy efficiency of their homes. Old buildings use a lot of energy, making them a major source of carbon emissions as well as being uncomfortable and expensive to live in.

Many countries have introduced carbon reduction targets as part of the global effort to tackle climate change and the renovation of old buildings is essential if these targets are to be met. However, this kind of refurbishment work is costly and time-consuming for social landlords, which are non-profit organisations that often have several hundred homes to retrofit.

Transfer and expansion

GEA believes the Energiesprong’s flexible approach can be replicated in other countries and is committed to introducing the concept to as many territories as possible. The alliance is particularly focused on Eastern Europe and Energiesprong’s potential to help rebuild Ukraine once the war is over. In countries where there is little or no social housing, GEA believes Energiesprong can be adapted for other housing sectors and focus on specific issues, such as renewable energy.

The size of retrofit projects in the countries in which Energiesprong already operates is steadily increasing as the retrofit market grows, along with greater confidence in the process among housing providers. GeWobau Erlangen, in Germany, has committed to retrofitting 6,000 of its 8,800 homes with the Energiesprong approach by 2025, and there are plans to renovate an additional 55,000 homes across the EU and USA.

Energiesprong clearly demonstrates that it is possible to retrofit very large numbers of homes to carbon neutral standards, in a quick and cost-effective way. As the number of renovations increases from tens of thousands to millions of homes, many more tenants will benefit from increased comfort and reduced energy bills. However, Energiesprong’s potential to dramatically reduce global carbon emissions, means it is the planet that has the most to gain.