The tool now offers new features that allow you to assess the interactions between component layers for a quantitative measure of reversibility, a key principle of Design for Disassembly (DfD). Considering reversible design is a prerequisite to a robust circularity assessment, as materials can not be reused or recycled if they cannot be removed from the building without damage or contamination.
The methodology has been developed in collaboration with Aalto University. An extensive literature review of existing reversibility methodologies was conducted and the results have been evaluated through interviews with industry experts and three real test projects.
The tool has three new inputs: Structural role, Accessibility limited by, and Connection type.
For each layer, first select a Structural role and Connection type. Connection type affects the calculation result, and the weighting factors (derived from the literature review) are made visible for each option.
Structural role does not directly influence the result but is used to group results and to help in determining the accessibility of layer. Accessibility limited by is based on the Connection type of the layer that is blocking access to the layer in question.
In the example below, the Load-bearing layer has a Screw connection, which is partially reversible and therefore has a factor of 0.6 (a high score, easier to disconnect). However, it is blocked by a layer that is connected by welds and inherits Weld-connected layer for the accessibility value, which has a factor of 0.2 (a low score, harder to access). This combination describes how the choice of connection type is important across multiple layers, otherwise limiting access prevents proper disassembly.
In the scenario where one layer has multiple layers blocking accessibility, the value selection is made with the following criteria:
In the case of multiple layers preventing access to one layer, select the most difficult layer to disconnect.
In case of multiple connection types on one layer, select the most difficult connection type to open.
Most of the accessibility values are based on the connection type. The following options can be used in specific accessibility cases.
Accessibility value | Description |
Thin plaster layer | For cases where surface layers such as gypsum board, that do not have another layer blocking accessibility, have been plastered over. |
Soft seam | For cases where the connection between two layers is covered by an easily disconnected covering. |
Mechanically connected lid | For cases where the connection between two layers is covered by an easily disconnected covering. |