I have a Victorian mid terrace with essentially wasted space down the side of the rear. We were thinking of either extending the kitchen outwards by a metre which would mean:

Steels
Walls knocking through
kitchen refurb
Extension build up
New roof etc etc

Given the little additional benefit this would bring us we were thinking of a small 'lean to' accessed from the door coming off the middle room, it would only be to store washing machine, tumble dryer, clothes to dry.

We'd like to have as much light as possible as this area lights up the kitchen and middle room at the moment.

Thoughts on build up?

Yes that is about right, I'll try and get a picture later. what is the best way of uploading photos on here? I always struggle with sizing issues etc.