the walk in robe will be an extension from the current WIR on the left side.

do you tink it will be too much work since there is no plumbing near the area am proposing to make a powder room?

Nothing is to much work, just depends on your budget!

They will need to cut your concrete slab and extend your plumbing form your ensuite, assuming you are going to redo the ensuite, you may as well do it at the same time.

Only a plumber could give you a real idea of prices and difficulty. As above anything can be done if you spend enough money. Depending on where the plumbing is externally it may be able to come through the bedroom where they would only need to pull up the carpet and go through a couple of walls before they start digging up a trench in the concrete. There are set depths for sewer and it needs to have a fall so waste drains away so not simple.

Some dimensions of all the rooms and hall would help. You may get more storage by building a wardrobe into the hall leading into master. But this all depends on dimensions. I’d budget 10-15k for a simple fit out assuming just shelving in pantry, no new electrical or cabinets. But get quote for I’m plumbing first.

The following is a basic idea of a possible layout, working with rough dimensions and allowing 900 x 2m for the powder, and wall depths. My approximate dimensions 2990 x 3880 give or take a few CM's

Placing the powder room as such brings it closed to the existing plumbing

The 2m measurement is the Powder room stepped back which will also include a small vanity.

I'd be thinking about extending kitchen into dining area and closing off access to bedrooms where it is and moving doorway so it's more opposite laundry.
You could still extend pantry and WIR where they are but wonder about benefit of additional powder in that location.

A four bedroom house has demand for a 3rd toilet and placing this 3rd as a powder room which services the large study/ MFR perhaps working from home and having clients needing access to a toilet, arriving home via the garage, plus a better placement for guests not having to use the toilet that services the 3 bedrooms.

Try and get toilet access off hall not opp dining

thanks everyone. i will contact a plumber and get information on how it will be best to move forward