New Bathroom for semi detached away from external walls

[RedesignReg2]

I am looking to redesign my new home but due to its proportions i am forced to move the bathroom from the outside face of the house to be between bedrooms at front and rear and backing onto party wall. This will require that i route waste from a toilet, basin, bath and shower across the width of the property (5.5m).

I have read the part H regs and understand that in an unvented system i meet the regs regarding fall (18mm/mtr) and max distance of 15m..

As regards the basin, bath and shower i see that i am looking at a max of 3m for 40mm and 4m for 50mm pipe with a fall of 18-44mm/mtr.. i need a longer distance for these so the question is how? should i be looking at vented solutions? if vented then where would i vent to bearing in mind that pipes will be crossing the width of the house (yes this will be the shortest distance to an outside wall..)

Novice amatuer Plumber gratefullt requests expert guidance

 

[kevplumb]

strap them into a stub stack on the toilet drain

 

[bengasman]

I would strongly suggest that in a situation like this, and not having any plumbing experience, you engage a pro, if it turns out there is a problem after you finish the job, you are in deep ........
Are you aware that this project is notifiable to lba?