I spent some time yesterday trying to determine the right grid size for the aforementioned roof structure that I am working on for the Marsa Open Centre. I made a series of 1:50 models that helped to show how various grid sizes might relate to the human body (that is, if the human body was completely bright orange). The first series of models present a piece of the grid at 4 different sizes (4 x 4 m, 3 x 3 m, 2 x 2 m, and 1.5 x 1.5 m respectively) completely out of context just to get a sense of their size in relation to the 1:50 human. The dimensions were chosen based on the idea that the members could be easily cut from standard lengths of structural steel (6, 9, 12 m) without wastage and were of a size that could be handled by 2 or 3 people.
I then inserted the best candidates (the 2 and 3 metre grids) into my 1:50 model of the entrance courtyard to see how they felt on the site and the types of spaces they created. I wanted to decide on 2 grid sizes: a small one for outdoor gathering spaces and a large one that could span existing buildings and have greater structural possibilities. I tested the small grid options in the courtyard space.
3 x 3 m grid option in context
2 x 2 grid option in context
As you may be able to see from the photos, it looks as if the 2 metre grid is a bit constricting while the 3 metre grid allows for more interesting spatial experiences and fits better in the courtyard. However, these first impressions might change.
Finally, I used the 2 metre grid option in my 1:100 site model (thus making the 2 metre grid a 4 metre grid). In this context it would be acting as both a roof and also a structural system for hanging the community centre bridge and other rooms.
I was worried that the 4 metre grid might feel too large but it actually seemed to fit rather well in this context.