Classification of Raw Materials

Starting from the building materials, raw materials are derived by means of formulas (“recipes”). Appropriate sources for building material formulas are, among others, Ökobaudat, Wecobis as well as the declarations made by manufacturers of construction products and trade associations for construction products. Raw material classifications are based on national raw material reporting (Lutter et al. 2018), regional plans and similar plans.

Raw material allocations are available for most of the mineral building materials. For each building material group, a relevant building material was selected, its formula determined and used as a proxy for all other building materials in the building material group. In each case, the building material was selected that occurs most often in the buildings (in t/m³ gross volume) in terms of mass (basis: analysis of residential building types). The associated uncertainties should be taken into consideration (Schiller et al. 2022).

The allocation method used for the mineral building materials can be transferred to the non-mineral building materials.

If ingredients are listed in the formulas that have already undergone a manufacturing process, these are also broken down further according to their manufacturing formula (e.g. cement).
Water is not recorded here in terms of quantity and is not shown as a raw material, knowing full well that it is required in many manufacturing processes. If water is present, it is "calculated out" of the formula. This increases the proportions of the other ingredients accordingly.