Converting a Victorian outside toilet to a utility room- idea of cost?

minibbb

We are just about to buy a two bed Victorian terrace house which comes with it's original outside toilet (although the toilet itself has been removed)

I was thinking about having the toilet converted to a mini utility room to house the washing machine/tumble dryer and knocking through from the dining room so it could be accessed without going outside.

Does anyone know what sort of costs this may entail? I'm guessing it would need to be insulated as essentially it becomes a mini extension.

I'd also need power/water supply sorting out if the water supply had been removed- not sure on this. Any thoughts appreciated!