Building regulations - do we need a manhole?

[dodgem]

We have moved the bathroom and it's not possible to connect to the existing soil stack which we share with upstairs flat.

We can connect to the underground waste pipe (clay) between the soil stack and existing shared manhole 1m away.

Current options we are considering:
1) add a branch to the existing underground waste pipe between the soil stack and the existing manhole.

2) connect directly to the existing manhole and add a new soil vent pipe.

Question:
- do both options meet building regulations?
- does option 1) need a new manhole over the new branch? I assume option 2) wouldn't need a new manhole.
- the new waste pipe from the toilet to the outlet is 3-4 meters. How many rodding points do we need? I assumed 1 every 3 meters?

Thanks in advance.

P.s. we want to avoid building another manhole, especially when there's one within 2 meters of the property and accessible!!

 

[oldbutnotdead]

You need sufficient rodding points so that you can clear blockages (usually by rodding with the flow)
Your option 1 would be iffy- underground branches aren't best practice.
Option 2 would be ok but usually you have to meet the existing pipes at invert level (ie not just shove a pipe in halfway up the hole).
The whole job is complicated by you sharing drains with the upstairs flat- you might have to get permission from yr water company as well as building regs