With 390/1, the SIA is setting new standards in climate-friendly construction
05.09.2025
Climate change is one of the biggest global challenges. With the new SIA 390/1 climate path standard, feasible but effective target values have been available since the beginning of this year. These are aligned with the federal government's 2050 net-zero target and show a reduction path for net-zero buildings.
Picture: Timber frame construction as post and beam structure ©Primula Bosshard
Project: Château d'eau school center, Marly
The new standard specifies the greenhouse gas emissions that a building may cause over its entire life cycle - from construction to operation to demolition. With the introduction of the SIA 390/1 standard, the SIA is for the first time presenting a reduction pathway up to the year 2050, which should lead to genuine net-zero buildings.
Climate path calculations as a planning tool
SIA 390/1 requires a life cycle assessment: all greenhouse gas emissions from construction through operation to dismantling are balanced and compared with the target values. The standard specifies two levels of ambition: Target value B as a base value (corresponding analogously to the previous target values in SIA2040) and target value A as an ambitious value that explores the limits of what is feasible.
Such calculations provide answers to key questions early on in the project:
- How do the choice of materials and construction methods influence the carbon footprint?
- Which measures will have the greatest effect?
- Is the project within the defined ambition level?
Timbatec supports you in the implementation of SIA390/1
As a specialist in building physics, we take on an extended task in the project for the implementation of SIA390/1 if required. Our building physicists provide the following key foundations for climate-compatible planning:
- Create climate path calculations for new buildings & renovations
- Carry out life cycle assessments to optimize the choice of materials
- Develop strategies for sustainable & circular building concepts
Lowering path residential conversion
Lowering path residential new build
Timber construction as a contribution to achieving goals
When it comes to climate-compatible construction, building with wood is one of the major levers and our strength. Wood is a renewable, low-greenhouse gas building material that binds CO₂ and stores it in the long term. Its production causes significantly lower emissions than concrete or steel.
Measurable advantages:
- Up to 24% less CO₂ emissions during construction compared to solid construction (Wüest Partner study)
- Carbon storage over decades, regional availability and short transportation routes
Conclusion and further information
Those who incorporate the requirements of SIA 390/1 from the outset and make targeted use of the potential of timber construction and other levers create the basis for sustainable, climate-friendly construction.
📄 More about the standard ➡️ SIA / Climate and energy | Lowering pathway
🌲 Inspiration for building with wood Lignum Magazine: ➡️ Sustainable building with wood
👉 Report in espazium - the publisher for building culture
