I have a loft conversion. It has very little standing room. The house is a semi. I want to square off one one side of the roof and fit a dormer.

Before I  go any further, what is the minimum this will cost. Thank you.

How long is a piece of string??. 🤷‍♂️ as we have no idea what work is required you are better getting quotes fir the work you want. 

Thank you. I will research further. My reason for the question is, I had a buildings designer look at the loft and he seemed knowledgeable and helpful and did not charge for the visit, and gave me a reasonable quote for his services. I would like to hire him, but I asked for a rough cost of build, and said not worth having plans if I cannot afford it. Planner said £5k to £15k for the build but upon Google research I see figures of £30k upward. I will ask for some quotes from builders. Thanks.