Which trades to advise on adding bathrooms - plumber?, architect or builder?

ChasingtheWelshdream

I've been lurking here for ages ages whist gradually renovating a 'liveable wreck'  and pondering several improvements as and when we have the money. Now we have funding in place so I'm itching to get going. Until now we've only had informal chats with tradesmen on vague ideas, so now we're wondering how best to start.

We are a 5 bed semi over 3 floors, with one bathroom and a downstairs loo. The bathroom is on the first floor away from the bedrooms so we want to add at least an en-suite and possibly a shower room on the top floor, nearly above. There is plenty of space to pinch from the bedrooms but our initial issue is the layout - where best to place the bathrooms vs the plumbing practicalities. We've had varying opinions as to whether we can utilise an existing but unused cast iron soil stack, which is just about on the limit of building regs, distance-wise.

It may be more practical (but costly) to install a new stack into the underground pipe which we believe runs adjacent & parallel to the side wall. Unfortunately this area has been concreted over and we can only best guess without excavating at this point.

Which brings me on to my main question. As the potential installation may not be straight-forward, who would be the best trade to approach? A plumber? (one said fine to connect to the stack, another said not possible). A builder/groundworker? (to advise on installing a new stack) An architect? (to advise best layout) 

We are able to install the santiary ware ourselves once the pipework is in place, but it's getting to that point we are stumped with. 

Any thoughts?

ChasingtheWelshdream

On a similar vein, DH and I differ whether it's worth adding the top floor shower room. DH says it's not needed and a waste of funds. I feel it's worth exploring as a good chunk of the cost would be getting the water/drainage to the en-suite below and maybe not a huge amount more to extend the pipes to the floor above.  Also I'm thinking of saleability when we eventually downsize as the top floor bedrooms are huge and a shower room would be practical up there.

I'm happy to be wrong, so again, all thoughts are welcome!

Chickereeeee

ChasingtheWelshdream said:

On a similar vein, DH and I differ whether it's worth adding the top floor shower room. DH says it's not needed and a waste of funds. I feel it's worth exploring as a good chunk of the cost would be getting the water/drainage to the en-suite below and maybe not a huge amount more to extend the pipes to the floor above.  Also I'm thinking of saleability when we eventually downsize as the top floor bedrooms are huge and a shower room would be practical up there.

I'm happy to be wrong, so again, all thoughts are welcome!

If you don't add a top floor shower room, think seriously on extending the plumbing up there anyway, capped off but accessible. Then, you can install later if you change your mind, or if you sell, you can let buyers know what you have done. Then they can install their choice of fittings with (greatly) reduced cost.  (So you get increased sale-ability without the cost of actually installing).

ChasingtheWelshdream

Thank you, definitely worth thinking about. :-)