## 3 Results
### Circularity Assessment Frameworks
#### 3.2.5 Circularity Criteria and Guidelines  
This type of framework delivers descriptive criteria and recommendations to deliver more creative solutions for a circular economy. Multiple guides aim to provide general guidelines that apply to different areas to develop a circular mindset and design culture for practitioners and young professionals (e.g., the circular design guide). Other guides deliver design criteria particularly for buildings (the reversible building protocols).  
1. The Circular Design Guide  
The Circular Design Guide is developed in collaboration between the Ellen MacArthur Foundation (EMF) and IDEO to help designers create more effective solutions for a circular economy. The guide is not dedicated to building designers or the construction industry. It rather targets whichever designer and product developers in any industry can benefit from the circular economy approach. This guide consists of a series of methods to build up a circular mindset and reframe questions to get started with the circularity challenge. The value of this guide lies in experiencing, exercising, and training through multiple methods to transform designers into being intuitive about circularity. The reason is that design practice is largely based on experience and less on tools [67].  
2. The reversible building protocols  
Based on the principle of closed-loop systems and resource productivity in a circular building, [PERSON] [26] approached the concept of adaptability by developing what she called the \"Reversible Building\". Building reversibility manifests at three different levels: spatial, structural, and material happening through transformation actions such as separation, elimination, addition, relocation, and substitution of parts. [PERSON] considers the level of building reversibility a key indicator of circular buildings and is measured by transformation capacity on three levels and reuse potential of all parts at a building, system/component, and element levels. [PERSON] argues that transformable buildings' elements cannot be attributed to a fixed number of layers as different scenarios might occur. Each scenario calls for a different number configuration and hierarchy of changing layers.  
The reversible building approach introduces a comprehensive framework of multiple complementary strategies taking place concurrently, including design for adaptability (DfA), design for disassembly (DfD), and material reuse and recycling. These strategies support the waste hierarchy assumed by the circular economy by questioning the end-of-life options to maintain closed-loop value chains.  
To understand the physical capability of buildings to cover as many scenarios as possible, [PERSON] [26] proposes four forms of spatial reversibility of transformable buildings:  
1. Trans-functional: switching between four functional scenarios: housing, office, education, and public buildings.
2. Adaptable mono-functional block: when the main use persists while the habitants' requirements change as the family members increase or grow older.
3. Transportable from one location to another.
4. Transformable: when it has the capacity to perform all of the three previous changes.  
As for structural reversibility and reuse potential, the type of transformation required informs the type of reversibility required. For example, a simple, functional adjustment requires a partial level of reversibility. In contrast, a high level of reversibility assumes dismantling the structure to the initial set of elements so they can be reconfigured to create a new structure of new function or to perform major alterations. Key indicators are the functional independence of a building's elements and parts and the exchangeability of its systems, components, and elements with minimal interface interactions, causing no damage to juxtaposition parts.  
The reversible building model has been further developed through the European project of BAMB (2015-2019) where the protocols were implemented and tested on several pilot projects.