l-shaped

I shall make this clear with a diagram. I wish to build a side extension within PD. How big can I build a side two storey side extension onto the old single storey house? Originally people lived in loft, there still is a gable first floor window. House is pitched roof and extension would follow...

Hi We have an L-shaped cottage. It's been L-shaped for at least 150 years, probably more. Please see the attached images. The blue bit is about 350 years old (original). The green bits are about 150 years old (original). The bits in white were added after 1948 (extensions). We've been...