Calculating B1-B3 EN 15978 modules

  • Oliver Morris

    Hi ETool,

    We wondered how B1 (use), B2 (maintenance) and B3 (repair)EN 15978 modules are currently calculated in the ETool software? We are having conversations with clients who are interested in understanding how Life Cycle and end of life emissions are calculated.

    Any thoughts would be really helpful.



    Hi Ollie,

    Thanks for your question!

    B1 refers to impacts of materials in use. Data in this field is still in its infancy and at present only concrete based materials will show some in-use impacts due to carbon sequestation at its surface. The standards and calculation methodologies are still under development within the industry and as the field matures we may see further impacts from say toxins in paints impacting on air quality and human toxicity (although at a global indicator level this is likely to be quite a small impact over buildings life cycle!)

    In eTool B2 captures both maintenance (B2) and repair (B3), Maintenance impacts will come from eTool inputs for people and equipment, i.e. window cleaning tradestaff in our window templates. In materials we have options for repair interval and percentage of material repaired i.e. re-pointing in a brick wall template – 10% of the mortar in a will be repaired every 50 years.

    Hope that helps!

    Hi Fei,

    On a similar topic, my understanding is that Stage A1-A3 in EN15978 covers the embodied GHG emissions of a product/materials. Can you confirm if my understanding is correct? We can extract the eTool results of Module A1-A3 to quantify the embodied GHG emissions.

    Our client is interested in understanding the embodied GHG emissions of concrete and how might we make improvement on the usage of concrete.


    Hi Jee Wei, yes eTool’s life cycle modules are based on EN 15978. I would say that the embodied impact of a product/material would probably span A1-A5. Please refer to the system boundary table in this post for the module descriptions. And yes you can find the results for A1-A5 from eTool via the ‘EN15978’ tab of the design page. Hope that answers your question.

You must be logged in to reply to this topic.