Study reveals how to reduce the carbon footprint of houses

Bruno van Pottelsberghe, Rector of Corvinus University of Budapest, and Joran Douhard, PhD candidate at the Solvay Brussels School of Economics and Management, compared standard houses (detached and semi-detached) to sustainable versions built with more environmentally friendly materials. The effectiveness of building material was calculated in terms of reduced carbon dioxide equivalent (CO₂eq) emissions per euro invested. This standardises the impact of emissions, e.g., methane has 28 times the warming potential of CO₂ so 1kg methane equals 28kg CO₂eq. 

The researchers found that most CO₂eq emissions come from the use of a house (operational stage), rather than construction or maintenance, with 65% of a house’s total carbon footprint attributed to energy used during its lifetime. 

When all costs are considered (construction, operation, maintenance), the total cost of ownership of the “more sustainable” houses is 7-11% higher than the standard houses. Maintenance costs are also 20% (detached) and 13% (semi-detached) higher in sustainable houses, due to the more frequent replacement of sustainable materials.  

“The impact of the construction sector is country dependent, so international comparisons should be made with caution (e.g operational impact is highly dependent on heating systems, which vary a lot between regions). Such heterogeneities are detailed in the state-of-the-art section of our study. Nevertheless, some observations can be easily generalised to a wider EU context, such as the lower overall impact of timber frames compared to concrete structures or the imbalance between embodied and operational carbon impacts. As the methodology and data are available, interested readers will be able to easily adapt our results to local specificities.”,  say the authors.

The study also shows that certain components of a house have greater influence on carbon footprint. For example, sustainable material used for external walls and windows had greatest impact, reducing emissions by 6kg and 3-6kg per euro respectively.  
 
As the residential sector accounts for 17% of all carbon emissions globally, this sector should be a focus point for those hoping to reduce society’s carbon footprint, and this research indicates where the use of sustainable materials could be prioritised for greatest impact. 

These findings were first published in the Journal of Cleaner Production.