Moving/extending vanity waste drain

Welcome to the forum.
Unwritten rule of this forum is
pics tell a thousand words so give us a pic of the existing vanity with doors open showing existing waste.

You will then get the answer you need.
FWIW, what you propose is not all that easy as you have to cut the pipe down well below the top of floor to be able to cut it low enough to fit an elbow and still be below the top of floor
without damaging the pipe in the process
I would suggest you simply run the pipe as is through the base of the new cabinet, unless of course you want to run the pipe to the wall or into the wall ??

Thanks for the reply cyclic.
Please see photos below to assist.
In regards to simply connecting to the existing floor outlet it is not really an option as I need to move the outlet to at least on the wall preferably in the wall.
This is because the main reason for the ensuite mods is to make it wheelchair accessible and as such will need at least a slim wall mount vanity or probably a wall mount basin only.
As you can see the floor waste is a fair way out from the wall, probably about 400mm, so having a waste pipe in the middle of the area under the basin/vanity obviously will not work for the wheelchair access.
I do appreciate that the option I mentioned, to partly cut the floor and join to existing pipe, would not be easy to do but is potentially something I could do myself, if it does not break any codes/rules, where if it has to be the full slab cut I think this is something I would have to get plumber or builder to do to cover the building code work for the slab and membrane.

Should it be done by a plumber ? yes
But only the install of the pipe in or under slab.
Cutting and jack hammering can be done by anyone.
If the floor is waterproofed then that should be reinstated.

Every day people walk out of plumbing supplies, bunnings etc carrying plumbing materials and no one cares.

Thanks cyclic.
I appreciate the info and having done some previous reno work I understand the pipe connection should be done by a plumber, which to my thinking is a bit much to have to pay hundreds of dollars to get someone to glue two pipes together. If you think about it in terms of potential danger in relation to action then only a qualified mechanic should be allowed to change a car tyre as the potential danger of doing something wrong, eg. nuts to tight/loose, wrong wheel/tyres used, then the potential for serious outcomes is much higher than connecting a pipe wrongly.
Anyway enough of my rants. My main concern here was is it Ok to have the pipe running along inside the slab rather than a simple penetration as is currently the situation.
I will need a plumber for the complete reno work including new shower drain etc so could get them to do this work as well.

Do you happen to know what configuration is under the kick space ?
Reason being that we had plumbing they was run horizontal in the kick space, it also looks like there may have been an old connection further back in the cabinetry.

First step is find out what you are actually dealing with.

Originally Posted by jnlamb

Thanks cyclic.
I appreciate the info and having done some previous reno work I understand the pipe connection should be done by a plumber, which to my thinking is a bit much to have to pay hundreds of dollars to get someone to glue two pipes together. If you think about it in terms of potential danger in relation to action then only a qualified mechanic should be allowed to change a car tyre as the potential danger of doing something wrong, eg. nuts to tight/loose, wrong wheel/tyres used, then the potential for serious outcomes is much higher than connecting a pipe wrongly.
Anyway enough of my rants. My main concern here was is it Ok to have the pipe running along inside the slab rather than a simple penetration as is currently the situation.
I will need a plumber for the complete reno work including new shower drain etc so could get them to do this work as well.

To do it the correct way cut through the slab and hook onto the pipe below the slab.

Hi droog,
Yes i do know what is there.
The current vertical pipe you can see towards the front of the cabinet connects directly to the waste outlet that goes straight through the slab at that position.
You are correct that there was a previous connection further back in the cabinet.
This is because I temporarily moved the cabinet and wall back to allow for some level of maneuvering the wheelchair in the existing space and moved the basin outlet connection to still connect to the original waste.

Thanks cyclic. I thought that was probably the case.