Help - Where to start with Extension

Credit-Crunched

All,

Apologies if I am being very basic, never attempted this as this is my fist house and I work in the world of finance! (any tax advice I am your man!)

We have moved into a property with the back half of the house half and half roof as shown below. What we would like to do is carry the tiled roof across and complete the roof taking away the plastic top as its bl***dy horrible!

WE would be putting to sky lights in to retain the light, however my question is would this need planning permission as we would be replacing the right hand side plastic wall / window with a brick wall. So in essence the actual size of the building will not change just the physical construction.

Also do i need plans, who do I contact next regs or planning permission.

A very Confused man.