The good thing about these buildings is that they come in all shapes and sizes. For example you can get a corner summer house that will fit perfectly into one corner of your garden. You could site this at the far end of your garden to provide a quiet retreat from the rest of the house.
Another example would be to get a summer house to include a veranda. This provides a small area of decking outside the summer house. It also has a pitched roof over the top, providing an area of shade when you want to sit just inside the doorway and still be protected from the sun.
You can even get your shed and summer house in one building if you opt for something larger like the contemporary garden room summer house. This has a large summer room section with an integral shed at one end, with its own access door.