Fittings manufacturers guarantee their products for a minimum of 25
years.

http://www.yorkshirefittings.co.uk/d...ks/tectite.pdf

I had three serious leaks in my brand new Barratt house in just over
a year, all due to plastic plumbing with push fittings. There must
have been 50-100 of them in the house, what's the statistical chance
that one will pop again in the next few years? Pretty high I think.
If I have to use one or two on retrofits then maybe, but I don't care
what Yorkshire Fittings say, personally I'd say no way in hell I'll
ever use plastic plumbing with push fittings again to any serious
degree.

In my previous new house build (France) the plumbers arrived with
rolls (rolls, not lengths) of copper pipes. Not a single connector
anywhere except for three distribution points and the taps/radiators.
And not a single leak in the four years we spent there.

Why plumbers in this country still insist on dodgy joins every ~2m of
plumbing installations in brand new houses is a mystery to me.