Diagrams 3.10 and 3.11 show the maximum encroachment of basins into the WC access zone – the maximum penetration is typically 200mm, but 300mm adjacent to a WC. In wheelchair accessible layouts (diagram 3.11 and paragraph 3.36h) the intention is that there is a clear zone from the floor to the underside of /drainage/pipes/ services of between 400-600mm. This is to maximise ease of approach, whilst recognising that services have to be accommodated in some form. It is anticipated that pipes and drainage may need to be through-wall penetrations to achieve this result rather than running to the floor. Diagram 3.16A shows wash hand basin access zone encroaching by 200mm, in line with requirements set out in 3.11.