This would be a very good and helpful manual for carrying out conversion work in the UK. It is full of copies of the relevany documentation that has to be filled in and indications of when this has to be done and how to interact with council housing and planning departments. I don't know for how long the documentation will remain current and it only applies to the UK.
What it isn't is either a book on the aesthetics of conversions (though it does have some very interesting examples) or a 'how to do it' approach from a builder's point of view. Perhaps more a client-to-architect-to-planner viewpoint. I found the 'what do you want' checklist useful but since my project is in France about half of the book was wasted on me.