The reason for refusal on this planning application is simple, The restricted width of the site, the proximity of neighbouring properties, the change in land levels and the layout of vehicular cross-overs, mean that it is not possible to accurately assess the proposal without further details of the access, scale and layout for the proposed dwelling.
Amazingly, these details were requested by the planners as soon as the application was registered, but the applicant submitted no further detail. When you are going for an application on a difficult site, you need to provide the proof that it can be developed see location here.
PAPA Says - Just submit a detailed planning application, it looks very simple to get an approval.