As net-zero goals impose increasingly stringent requirements on buildings, urgent action is needed in the design process to reduce greenhouse gas (GHG) emissions and comply with forthcoming mandatory targets. While the scientific literature is dense with measures to mitigate GHG emissions, practitioners often lack clarity on the level of effort required during design to stay within specific targets. This study systematically quantifies the GHG emissions reduction potential of various measures applied to a reference building (multi-family and single-family houses) in Switzerland, assessing their effectiveness in meeting targets along the life cycle phases. To this purpose, a parametric model is developed to generate a detailed bill of quantities based on a few initial parameters, with measures applied by adjusting relevant parameters or materials. The results indicate that current standard practices for new constructions fall significantly short of meeting existing targets, particularly in terms of upfront and replacement emissions. None of the measures tested in this study allowed to reduce GHG emissions below the 2025 target by itself. However, avoiding underground floors and substituting materials for structural elements show the greatest potential to approach upfront budgets. Achieving the 2025 embodied carbon targets requires combining at first two essential measures, one of which must involve either avoiding underground floors or optimizing structural elements. Additional effective strategies include substituting materials in non-structural elements, designing compact building envelopes, and opting for simpler preparatory works. Achieving operational emissions targets in new constructions demands a substantial increase in on-site renewable energy generation. However, this raises embodied emissions, creating an additional challenge to remain within embodied carbon budgets.
