Costs of converting barn for function room/wedding venue

[didee]

I know estimating the cost of any conversion - especially a barn - is really hard but I'm stuck in the chicken and egg situation of having to budget/cost/plan for the cost of conversion before we go ahead.

We do not need all the fixtures and fittings we would in a house but do need it to be functional, dry, warm and light plus proper flooring etc. Can anyone give me a rough ball park figure of what this might cost us... I won't hold you to it. Or maybe someone else has carried one out and knows what it costs them.

Thanks very much
Diane