Cost savings on new build with plastic piping questions.

[Mottie]

On a 3 bed, one bathroom, one en-suite, three storey new build house with a combi system, are there any cost savings to be made in time and materials by using plastic piping throughout for the heating, hot and cold water supplies. Would probably use copper where pipes are visible. If so, is there one make of plastic pipe that is better than the others and why?

 

[John D v2.0]

For plastic the pipe is cheaper but the fittings are a lot more expensive. That means for long runs your plastic is cheaper because you can just bend it all the way. But complex junctions would add up in fittings
Plastic is also about as easy as Lego so no faffing with spanners or fire. So labour is very cheap.
You can use push fit fittings with copper pipe if you like where needs be.
The absolute cheapest way for materials would be plastic for long runs, but switch to copper soldered whenever you have plenty of joins together.
Plastic fittings are also bulky and ugly.
Plastic pipe has slightly higher resistance then the equivalent copper but less fittings helps mitigate that.

Summary is plastic should be cheaper to buy and much cheaper to fit. PS I use speed fit because it's readily available and cheap enough online.

Hope that helps, good luck with your build.

 

[SandyLyon]

Nearly all new build will use plastic, as above, pipe will work out cheaper than copper, but the fittings more expensive.
If designed correctly you should use less elbows and couplings, you will need the same amount of tees.
It’s the labour that represents the biggest saving and the “installed cost” will work out far cheaper, also have you ever tried threading 3 metre lengths of copper through “I” Beam / Engineered Joists.
We only use Hep2o on our installs with copper on show and airing cupboards.

 

[OvertonPlumber]

Remember to pressure test to 18bar lol

 

[Aquaheat]

Remember to pressure test to 18bar lol

Wet test not air!

Jon

 

[John D v2.0]

Remember to pressure test to 18bar lol

10 bar!!
Edit: for speedfit

 

[SandyLyon]

Remember to pressure test to 18bar lol

18 bar on “O” ring first fittings (PolyPlumb etc)
1.5 times working pressure on Hep2o etc