Thanks for the replies. I should of probably said the property is build complete.
To instal an outside tap at any or each wall of the building its easy. It's neither hard to run additional pipes through entire house if needed, Its the price you're willing to pay for it, in some cases price for redecorating walls, or replacing new floors and ect, not knowing many needed details, i can say it could turn into very very expensive instalation.
Distance to the nearest c/feed. Do you want pipes to be hidden under floor boards or them to be exposed on the wall.
Do you want everything done from A-Z , example - if it needs getting under floorboards, you expect all to be sorted to the smallest details, boards, type of flooring, skirtings, repainted if needed and ect. Or you're happy to pay for the plumbing installation only and sorting everything else yourself.
There's no straightforward answer to your question, but if you provide more details abour the job and your expectations on hidden/exposed pipewpipework or how would you like entire work to be carried out, plus a few pics of the area/rooms where work is expected, it would let us at least to give you maybe an estimate price and help you to understand how much work is invoved to do it.
Hope it helps