This summer my family walked through the the narrow cobbled streets of Saint Malo’s Inter Muros, it’s the type of place that makes you feel like an extra in a Studio Ghibli film. Our European cities are all full of charm, character, history and beautiful old buildings. This heritage presents a modern challenge, a huge proportion of these buildings are energy-inefficient, draughty and carbon-intensive.
75% of the EU’s building stock is considered energy-inefficient and the built environment is responsible for around 36% of the EU’s total CO2 emissions, so how do we change? New eco-buildings grab headlines, (although as I explored in an earlier post, our most efficient building is now 10 years old) but we have to find a solution for the older buildings.
The key to sustainable urban development lies in retrofitting.
What is Retrofitting?
Retrofitting is the process of adding new technology or features to older systems. For buildings, this means upgrading an existing structure’s energy efficiency and performance. This doesn’t mean slapping on some solar panels, retrofit is a holistic approach that can include improving insulation, triple-glazing windows, reduced draughts, heat pumps, heat recovery ventilation(MVHR), smart energy management and renewables.
What are the benefits?
The case for large-scale retrofitting is robust, offering a cascade of benefits:
The primary driver is carbon emission reduction. Retrofitting can significantly reduce a building’s energy consumption.
Inefficient buildings are expensive to heat. Retrofitting lowers energy bills, making homes more affordable for residents and protecting them from volatile energy prices.
Draughty, damp, and cold homes are linked to respiratory illnesses and excess winter deaths. Retrofitting creates stable temperatures, reduces damp, and improves air quality.
The retrofitting industry is labour-intensive and local. It creates a wide range of jobs in construction, manufacturing, engineering and design, providing a significant boost to the green economy.
Retrofitting allows us to improve efficiency without demolishing our architectural heritage. It’s an approach that respects the past while securing the future.
It’s not without its hurdles
The initial investment can be substantial, acting as a major barrier for homeowners and landlords.
Every building is unique, especially historic ones. There’s no one-size-fits-all solution, requiring careful planning to avoid issues like trapped moisture.
The works can be disruptive for residents, requiring temporary relocation or living around building work.
Sometimes, the predicted energy savings from design models don’t fully materialise in practice due to occupant behaviour or construction flaws.
European retrofit projects
The ‘Energiesprong’ Model (Netherlands & UK)
Perhaps the most revolutionary approach comes from the Netherlands. Energiesprong https://www.energiesprong.uk/ (meaning “energy leap”) is a holistic model that aims for net-zero energy homes with minimal disruption. Factories produce prefabricated insulation panels and new roofs with integrated solar panels tailored to a specific house or block. These are then installed over a matter of days, often while residents remain in their homes.
The result is a net-zero energy home with dramatically reduced bills. The model has been successfully piloted in the UK in Nottingham where it has transformed post-war social housing.
Plattenbau Transformation (Berlin, Germany)
Plattenbauten, or large-panel prefabricated buildings, were East Germany’s response when conventional methods, such as bricklaying, failed to keep pace with the effort to rebuild cities and meet housing demands, the GDR began exploring methods of prefabrication in the 1950’s. Composed of large concrete slabs cast in a factory and assembled on-site, Plattenbauten provided a fast, cost-effective and resource-efficient solution to the GDR’s severe lack of housing. To tackle the inefficiency of the buildings, the KfW refurbishment programme provided low-interest loans and grants for large-scale retrofits including comprehensive insulation, new windows, and decentralised heating systems. https://www.sciencedirect.com/science/article/abs/pii/S0378778817338744
References
European Commission. (2020). https://commission.europa.eu/news-and-media/news/focus-energy-efficiency-buildings-2020-02-17_en
Energiesprong UK. https://www.energiesprong.uk/
Energy efficient retrofit of a prefabricated concrete panel building https://www.sciencedirect.com/science/article/abs/pii/S0378778817338744