A group of Dutch housing associations that came up with a brilliant idea for retrofitting older homes has won the Gold Medal in this year’s World Habitat Awards. 

Energiesprong retrofits usually take less than 10 days and achieve a 70-80% reduction in the building’s energy use. Since 2011, more than 10,000 projects have been completed in seven countries across Europe and North America, and thousands more are planned.

The Netherlands-based Global Energiesprong Alliance (GEA) is the umbrella body that coordinates the approach. 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 so all the energy the building needs is generated by renewable sources on-site.

Energiesprong shows that it is possible to quickly and cost-effectively retrofit very large numbers of homes to carbon neutral standards. 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, and the planet will gain from Energiesprong’s potential to dramatically reduce global carbon emissions.

This story is adapted from the World Habitat Organization’s article about how they developed their strategy and about its potential for making retrofitting older homes much cheaper and more sustainable.

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, but retrofitting aimed at greater energy efficiency is costly and time-consuming.

So a group of Dutch housing associations asked manufacturers to find a faster and cheaper way to retrofit their homes at scale, promising that they would implement the best one.

The winning idea, ‘Energiesprong’, uses prefabricated insulated wall and roof panels that are attached directly to the existing building, speeding up construction and minimizing disruption for residents, as well as a range of smart green technologies. 

While 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 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. 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. 

Individual ‘market development teams’ work in the countries carrying out Energiesprong retrofits, including the UK, France, Germany, Italy, the USA and Canada. Working with government agencies and financial institutions to create policies that support large-scale building retrofits, the teams coordinate housing organisations, construction companies and technology manufacturers to launch pilot projects and then broker retrofit deals involving thousands of homes.

Buildings undergoing an Energiesprong retrofit are measured precisely so insulated roof panels and wall façades pre-fitted with high-performance windows can be made off-site. Prefabricating these and other building components creates a standardised product that can be manufactured in large quantities. 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.

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 throughout, and 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. 

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.

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..

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.

GEA 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.

Photo: The cover photo shows the prefab approach. The photo in the text is one taken by Tracey Whitefoot in Nottingham, England. Both shared by World Habitat Awards.