Life Cycle Assesment: What can a historic farm teach us about low-impact restoration?

In collaboration with the Danish Agency for Culture and Palaces, we have conducted a detailed Life Cycle Assessment (LCA) report of the historic Danish farm Kirkehøjgård's restoration using bio-based and locally sourced recycled materials. 

The restoration, conducted by Kirkehøjgård's owner, prioritized local, recycled materials and bio-based alternatives when added resources were needed and the heating system was upgraded to geothermal energy. Unlike typical restorations that rely on materials like mineral wool and reinforced concrete for insulation, this initiative chose low-impact solutions such as hempcrete, limecrete and leca, to name a few. 

Placing these solutions into the bigger picture, the Life Cycle Assessment report compared its restoration calculations to those of a standard renovation – revealing a 30% reduction in total CO₂ emissions. These numbers also emphasized that bio-based solutions can continue to uphold longstanding conservation values.  

A holistic approach to restoration

The conclusions of the LCA report emphasize the need for a more comprehensive view, if we want to continue to reduce the climate impact of restoration.

"The work on the report for Kirkehøjgård has given us greater insight into both the data and the calculation methods for existing constructions and restorations and clarified the need for a better and clearer framework for LCAs for these buildings. An insight that also requires a critical stance on the two new EU directives on energy renovation," say Martin Vraa Nielsen, Lead Sustainability Consultant. 

The figures show that although there are CO₂ savings to be gained in energy consumption on the operating side by adding, for example, insulation, this should always be weighed against the climate footprint linked to the materials that the solutions require, including the emissions associated with the materials extraction, production, and transport. 

Renovation processes are often too narrowly focused on energy optimization. The Life Cycle Assessment highlights the need for us to zoom out – using a broader outlook to effectively reduce the climate impact of restoration.

When comparing LCA calculations, it is important to note differences in methods and inclusions. Material choices, particularly bio-based options, and simple constructions can significantly reduce emissions. Prioritizing maintenance over replacement also benefits both the climate and conservation values, while demolition has a major climate impact. And finally, balancing conservation efforts with climate reduction goals can be mutually supportive.