Building deep renovation through prefabrication

The H2020 Infinite project showcases sustainable retrofitting through prefabrication, as seen in Slovenia's Ravne na Koroškem. A 1982 building is being transformed with eco-friendly panels, cutting energy costs while maintaining affordable rent, offering a model for Europe’s green renovation efforts.

Takeaways:

Sustainable building renovations through prefabrication: The use of prefabricated façade panels, sourced locally and incorporating energy-efficient solutions, significantly improves energy efficiency and reduces construction time and labour costs.

Community involvement: The project highlights the importance of involving residents and the local community from the start. By preparing residents for the renovation process and addressing their concerns, the project ensures a smooth transition and fostering strong local support.

A model for energy-efficient retrofit: The renovation serves as a model for retrofitting older buildings in Europe, showcasing how innovative, eco-friendly solutions can revitalize aging structures. The project demonstrates the potential for prefabrication to improve both the environmental impact and living standards in older buildings.

Buildings are the largest single contributors to greenhouse gas (GHG) emissions in the EU, with many European structures poorly insulated and consuming significant amounts of energy for heating and cooling. This makes the building sector a critical focus for reducing the EU’s environmental impact. In response to this challenge, the H2020 Infinite project introduces an innovative approach to demonstrate the potential of prefabrication in the construction sector. The project provides tailor-made, eco-compatible, affordable, and cost-effective retrofit solutions that can revolutionize the way we renovate buildings to improve energy efficiency. The project involves three case studies, and here we dig deeper into a case from Slovenia.

Prefabrication – the Case of Ravne na Koroškem

In the city of Ravne na Koroškem in Slovenia, a building, constructed in 1982, is undergoing a transformative retrofit, incorporating cutting-edge solutions for more sustainable construction. The building, with its steel-reinforced concrete frame and brick masonry, is a multi-use building housing offices on the ground floor and 71 residential units spread across four stories.

The building had not undergone any renovations since its construction, leading to poor energy performance due to a badly insulated envelope and windows, resulting in high energy consumption and costs. This issue is not unique, as many buildings across Europe and Slovenia face similar challenges. Recognizing the need for sustainable renovation solutions, the property owner decided to take a proactive approach to renovation.

“The building’s energy consumption was very high, which led to high energy costs for us,” explained the property owner. “We wanted to reduce these costs and improve the overall standard of the building.”

The renovation, expected to be completed by March 2025, also includes the addition of a new floor containing five apartments to be sold, helping to finance the project. The renovation includes the integration of prefabricated façade panels that not only improve energy efficiency but also include functions such as air ventilation and solar panels. During the renovation, residents continue to live in their apartments, minimizing disruption to their lives.

A sustainable solution through prefabrication

The prefabricated façade panels are made from locally sourced wood and are easily transported and installed, reducing construction time and labour costs. The renovation also includes installing energy-efficient windows and air ventilation systems, all produced locally.

“Prefabrication has a lot of benefits,” the property owner said. “It’s faster, less complicated, and the renovation process is smoother. However, it is still more expensive than traditional methods, which can be a barrier for other property owners to adopt prefabrication.”

Despite the higher upfront costs and that the project is not finalised yet, the property owner sees benefits. The installation of a new, more efficient heat pump has already reduced water and heating costs, which helps keep rent affordable for the residents. “From the residents’ perspective, the rent will remain the same. Heating and energy are included in the rent, regardless of consumption, so the financial benefits primarily come to us as property owners when we reduce energy costs.”

One of the most rewarding outcomes of the project has been the positive response from the local community. “The residents and local community are excited about the renovation,” said the property owner. “They are happy to see this happening in their city, and we believe this project will inspire other property owners to consider similar renovations”. Before starting the renovations, there was an anthropologist living with the residents for two or three weeks to ensure their involvement in the initial phase of the renovation. “We prepared the residents for this renovation, so they know what’s going on from the beginning and they showed great interest in the renovation and trying this new method with prefabricated facades”. Involving the residents from the start made them feel included and getting them onboard on the renovation.

Looking Ahead: A Model for Sustainable Renovation

Ultimately, this Slovenian case study demonstrates the immense potential of retrofitting older buildings with eco-friendly solutions. The renovation will transform the building into a model for energy efficiency, providing a comfortable and sustainable living space for its residents.

As the project progresses, it will serve as an example of what is possible when innovation meets sustainability—showing how prefabrication and energy-efficient solutions can breathe new life into Europe’s aging building stock, one building at a time.

Written by Jonas Calander and Emmanuelle Causse, UIPI
Photos by Gregor Sagadin, Stanovanjsko podjetje d.o.o.