Do WC pans need to pro-Diagrams 3.10 and 3.11 both state that the size of the sanitary units are given as minima in the furniture schedule in Appendix D. Using other sizes may affect the overall size of a bathroom or cloakroom. Using a larger unit than the 500x700mm WC + cistern given in the guidance may, therefore, impact on the overall clearances and room sizing needed to make a compliant bathroom, cloakroom or wet room. Larger units are permissible if the knock-on effect to overall room dimensions is factored into the sizing of a room’s layout. ject no less than 700mm in order to fit with the furniture schedule and also be clear of all boxing-in and pipework?