Which category is shed and summer house building?

I'm not sure how big you are thinking of building, but a shed or summerhouse/gazebo can be exempt from any sort of permission depending on the size (relative to the existing property), location (on the plot), the height of the building, the type of usage and whether or not it incorporates any service which generates 'waste'. Contact me and we can go through your wishes and see how they could be best accommodated.