The main difficulty associated with the application of graph theory to facilities layout is the conversion of the dual graph into a block layout. Hassan and Hogg (1989) presented a procedure to solve this problem. This paper gives some comments and critiques related to the problem and demonstrates that their procedure does not always work in a manner consistent with the adjacencies specified by the dual graph. In addition, rules for improving the procedure are developed. The paper is written in note format and the reader needs to refer to Hassan and Hogg (1989) for understanding the procedure and undefined notations.