Where to start with vague Extension/loft conversion plan?

Doozergirl

united4ever said:

Picture of pitch attached. I have merely popped my head through the hatch, it's not boarded to really investigate it.

Bit too blurry.  You want to get outside and count the number of brick courses from the eaves to the ridge.  Multiply that by 75mm and that gives you a measurement which is, erm, greater than your current available head height, but it's a start.  

united4ever

32 bricks which gives 2.4m. I guess a staircase, boarding, insulation, electric sockets and plastering would be the requirements. Then decoration and flooring. Maybe 2 velux windows/and/or a window on the gable wall? Probably velux would be better.

Doozergirl

It's really tight.  Looking at the window height, the ceiling joists are included in that 2.4, as is your ridge beam.  The maximum height at present isn't likely to be above 2.1 - then the process of conversion makes it smaller with the addition of 125mm of insulation, plus plasterboard, and allowing an air gap. 

If you can do it, you'd be looking to get a big dormer, otherwise you'll have very little useable space.