The overarching goal of this study is to answer questions related to the costs of implementing a Whole Life Carbon perspective in Germany. It is part of a series: another short study focuses on the  costs of the tools, qualification, and costs of conducting a LCA required for life cycle assessment, as well as the  costs, availabilities and trends of Environmental Product Declarations (EPDs) in the German market.  

For the purposes of this study, BPIE and DGNB evaluated 28 DGNB-certified residential buildings with regard to life cycle greenhouse gas emissions and construction costs.  

The results of the evaluation are summarised below:  

• The results show that life-cycle-optimised construction is not necessarily more expensive, but that compliance with life-cycle GHG reference or requirement values ​​is already achievable today with significantly lower construction costs.  

• A correlation between low operational CO₂ emissions in residential buildings and higher construction costs cannot be confirmed. In fact, there is a slight tendency indicating that buildings with lower operational CO₂ emissions also tend to have lower construction costs  

• A look at life-cycle costs shows that more focus must be placed on operating costs in the future. While the absolute values ​​of production costs remain almost the same, the share of operating costs in the total life-cycle costs increases sharply. Significant uncertainties regarding future energy prices, availability of energy sources, and maintenance requirements should be prioritised in the planning of new buildings.  

• The more energy-efficient a building is, the higher the average share of greenhouse gas emissions attributed to the construction phase. Older projects (certified under DGNB Version 2015) generate about one-third of emissions through construction and two-thirds through 50 years of operation. In contrast, newer projects (certified under DGNB Version 2018) already produce well over 50% of emissions during the construction phase.  

• The greatest potential for reducing construction-related greenhouse gas emissions lies in the building design and the choice of structural materials. Buildings with timber structures show the lowest construction-related emissions.  

• Among the analysed projects, no correlation was found between the consideration of broader sustainability aspects (as measured by the DGNB overall performance score) and construction costs.  

The analysis has shown that introducing WLC requirements is feasible and will not pose insurmountable challenges for market participants in Germany. The focus now must be on facilitating its implementation.  

To read the original report in German, click here.