This project summarizes the importance of reducing the embodied carbon of building materials and analyzes why that is difficult to achieve on small residential projects. It highlights problems with LCA data, misleading product literature and lack of awareness by design, engineering and building professionals. It calculates the embodied carbon of a house currently under construction and reviews the impact of  design decisions. It provides practical recommendations and guidelines for small projects. Appendices address i) why concrete has such high Global Warming Potential (GWP) and how this can be ameliorated; ii) whether wood in construction is really sustainable and should get credit for carbon sequestration, and iii) why some foam insulations are so much worse than others. 

Using XPS instead of the selected EPS would have added 85,000 kg C02 equivalents – as much as 210,000 miles of driving