Most councils issue guidelines for extensions to domestic properties in their area. For simplicity, I have reproduced a typical householder’s design policy
(Figs. 4.1(a)–(d)). This has only been reproduced as a guide. When designing any building, it is essential to obtain the policy document issued by the Local Authority having control over the area in question. The policies differ from council to council. As the information is fairly self-explanatory, I would suggest that you study the document as a typical example of the sort of requirements that are normal.