The key questions here are whether the plot lies within the development boundary of a village or, if not, whether your council has a specific policy allowing infill outside development boundaries. Finally, if there is an infill policy, does your plot meet the criteria? Generally speaking, infill constitutes the filling of a small gap in an otherwise built-up frontage. You can readily find out what policies apply to your location from your council’s local plan. If the situation is marginal, write to the council seeking its informal opinion on whether permission would be granted. If the reply is positive, by all means make a full (or detailed) application. If it’s still marginal, go for Outline Planning Permission to save risking the cost of having full plans drawn up.