sink waste to gutter drain?

[RegB]

I'm planning to install a new downstairs bog, shower, and basin and am considering drainage options. I've got two questions.
1. Can the basin/shower waste go into a gutter drain? (My house has separate drains for the gutter waste).
2. I believe basin/shower waste can go to the soil outlet but is this OK if the junction is at a point very close to the loo itself, eg 3 cm along the waste pipe from where it exits the wall? (I'm wondering if there would be a siphon effect).
Any advice much appreciated.

 

[Bahco]

1) No, unless it is a combined drainage system.

2) Will need an anti vac trap or other protection against loss of trap seal.

 

[RegB]

Thanks for that Bahco. It was very helpful. You wouldn't know where I could order that anti vac trap online would you?
Thanks again

 

[Bahco]

Go to a plumbers merchant. £5 tops

 

[kevplumb]

try the shop £ 2.59