Ensuite Loft conversion: Megaflow/Lead pipe uograde

Hi
Im a new user - homeowner.

We are doing a loft conversion with ensuite plus a side extension. We are getting a megaflow put in and some plumbers we had in earlier said we had enough flow to justify this. However my builders are now saying that their plumber does not think we have sufficient flow rate to supply the new megaflow for a 5 bed house with 2 bathrooms and a cloakroom and has suggested upgrading our water main lead pipe.

I am confused that different plumbers are saying different things. Is there an objective basis that I can use to determine if I should upgrade or not. Also does anyone know how much it costs to upgrade a lead pipe?

Thanks so much for your help

Yes get some facts and figures, dynamic pressure and flow rate from the mains, your plumber will be able to get these for you. Once you have these you can move forward.

Thanks - what are the guidelines for each that would be acceptable. Also, any guidance of costs would be much appreciated.

Pressure isn't the only thing you need to consider, it's flow rate too. Check your flow rate complies with whichever unvented system you choose, alongside your pressure, and go from there. If the flow doesn't comply, then maybe the advice you've been given is correct, but don't take advice on a hunch, make sure tests have been carried out before shelling out

Costs imposible to say, only that if the footings are to be dug for the extension, the digger can dig the trench whilst it is there. MDPE Pipe is fairly inexpensive, however ask your builder to supply a seperate quote.

Minimum you require is 22lpm and 1.5bar dynamic - Minimum.