new drainage

i want to add a sink in house in extension is it very messy and expensive to do (the waste pipe is in a bathroom about 5 ft away from proposed sink cheers

And your question is

Bahco, I would have thought the question was obvious when he said "Is it very messy". The absence of the question mark doesn't help, but I think it still counts as a question.

Barry, is the floor solid concrete or is it joists? If concrete, has it been laid already?

If the floor is already laid, I would think you would have to run the pipe round in the wall (if timber strapped), or box it in. Difficult to say without seeing any plans of the layout.

Barry it entirely depends what is currently between the sink and drain and whether you have a wall to fix to, and what the drain is like at that point....