Are you open to moving the toilet to another part of the house? If so, can you post the plan of the entire floor?

You said you need to keep the door at the bottom of the utility, but could it be moved to the wall on the left?

Thanks @HU-924188966 for your feedback.

I'd like to keep the toilet in this area/room ideally to keep the costs down.  Also there's a bathroom at the top of the stairs towards the front of the front of the house so distance/access wise this feels about right.

In terms of moving the door (out to the side of the house) to the other side of the wall, the boiler is just outside, so unfortnately wouldn't work without relocating the boiler.

The colourful square is the boiler at the side of the house.

Also a 3d layout.

In that case, the simplest ideas might be as follow:

Thanks for your comments @hu-924188966.  I did wonder about this as the fireplace is faux but wondered if it would be weird to go through the living room space into utility.  Definitely food for thought.

@minnie101 I'd never seen the sink over toilet unit.  Jumping in the car to see if I can see one IRL at a showroom to see how it would feel.  Thank you

I did wonder about this as the fireplace is faux but wondered if it would be weird to go through the living room space into utility.

The most direct path between the hall and the conservatory is effectively a corridor that is open to the living room, so I don't see why it would be weird to have a door to the utility there. Many people seem to hate having a WC open directly into a diner/living/kitchen, but in this case the utility acts as a buffer.

Otherwise, if you want to keep the existing entrance to the utility/WC space in the conservatory, you could put the WC by the door that leads to the boiler. But then it seems weird to me to have to pass through the WC to go outside, especially if this secondary entry is used a lot (if you like to hang your laundry outside, for example).