rarcherbythesea

I have a bungalow with what I am guessing is called a staggered/stepped front elevation (ie the front room sticks out well beyond the front door/porch by maybe 10-15ft). Does anyone know if I am allowed to extend the recessed part of the front to bring it inline with the currently furthest point so its all one flat wall - technically i wont be extending in front of the building line so should be permissable?