Apologies - I didn't give much information did I. My bungalow is a corner plot with highways at the front and side, and from my reading an extension would need planning permission but a porch, so long as it is no nearer than 2m to the highway, would not. It might well be that an extension...
Here's a question. Can you add a porch without an external door? Say you have a kitchen with an external door and you add a porch against that door - can that porch have no external door? My thinking is that this would provide a tiny utility room with more space if no external door was needed.