## 4 Examples of Critical Constructability Features in Facade Panels of the Orchard Commons Project
### Feature 4: Placement of Panel Embeds  
**Constructability Constraints and Experts' Knowledge:** Panel embeds are responsible for the connection of prefabricated panels to the rest of the main building structure, i.e., the receiving building elements such as slabs, columns, and walls. Therefore, the placement of embeds on the panels must be carefully designed in relation to the position of receiving elements. In a design where panels are not placed in a simple repetitive order, it is possible that panels with similar shape and dimensions require embeds at different positions. At the same time, due to constructability issues and to facilitate the fabrication process, practitioners often recommend normalizing the positioning of the panel embeds so that the variation in their location is minimal. This normalization of the embeds' placement is another type of constructability constraints.  
Although designing the placement of embeds on the panels requires close collaboration between different disciplines, especially between fabricators and designers, such collaboration was not possible in the OC project due to the project contract model and other project circumstances. Hence, there was no experts' input on this specific constructability constraint, and subsequently, this constructability constraint was not addressed through computational design, and no constructability features were specifically developed for this constraint.  
As a result, the positioning of the embeds in the OC project was the responsibility of the panel fabricator. The related calculation for all panels was performed manually based on the available experience on the fabricator's side. Figure 7 (left) shows the panel embeds designed by the fabricator for one of the facade panel types. Figure 7 (right) shows a worker adjusting the panel embeds on-site after identifying that those embeds do not meet the receiving embeds on the main structure.  
**Constructability Feature and Computational Implementation:** While no specific constructability feature has been developed in this case study to address the constructability constraint related to embed positioning, it is valuable to examine this type of feature in more detail, as it often necessitates close collaboration between designers and fabricators. This constructability feature pertains to constraints associated with optimizing the positioning of connecting elements on a building component, such as a facade panel. Its primary objective is to optimize the placement of connecting elements, whether they are extra connecting elements like embeds or mechanical fasteners such as rivets, screws, and nails, particularly concerning their intersections with other components, often of different types. Developing constructability features to optimize the positioning of connecting elements not only influences their fabrication but also significantly impacts their installation process. Inefficiencies in this regard can lead to additional workarounds and delays on-site, as observed in the OC projects.  
The constructability feature for optimizing the placement of connecting elements can be described in computational design through a location point on the host component (\(p_{(x,y,z)}\)), which is relative to the origin point of the host component. In cases in which components overlap each other, the implementation of the overlap in the computational algorithm requires the length of the overlap (\(l_{(d)}\)) in addition to the location point on the host component at which the overlap starts (\(p_{(x,y,z)}\)).