Well, it is finally finished - See pictures.
Thank you
@Kad - I did layout the pattern pieces on the floor to work out properly how much material I needed and it was very useful. This showed me that I needed 3.5m of material at 1.6m wide. But, the towelling I had in mind could only be sold in half OR one meter increments so I had to buy 7 lots of 0.5m or 4 lots of 1m and as the price for 0.5m was more pro rata, the price went up again together with a large amount for postage!
In the end I bought 4 bath sheets from IKEA (SALVIKEN) which were 1m x 1.4m each for £10 each which was not only cheaper than the towelling material but thicker (500GSM) and has towelling on one side and a waffle pattern on the other - lovely material. Thank you to
@Sewbusy who suggested using towels instead of material. I went for Dark Beige colour and picked them up from our local shop (Gateshead).
Further, I used the edging of the towels to make the tie loops - the pattern said to make loops with several thread lengths and to cover using a button hole stitch knot which didn't seem to be so professional to me. I also cut down the washing info label and sewed it into the seam to remind us how to wash it. And I am also thinking of adding a hanging loop to the collar area using the loop provided with the towels - although the robe is pretty heavy.
Making it was a reasonable amount of work but as the pattern says it is super easy, so I can't complain. I did however have to look up what it meant by basting. Everything was basted and then sewed. I thought basting was something you did when roasting turkeys at Christmas! I did mostly baste the parts together but sewed direct from pinned in some easier cases. I'm sure I never saw my mum basting - she always sewed pinned pieces.
I am very pleased with how it turned out although it was a bit tricky sewing on the double layered hood to the body and the facings. 4 layers of material that I had to squash down with an iron to get it under the presser foot, even with the extra lift of the foot. The robe is really warm and the hood is lovely being two thicknesses but is huge and if I made it again, I might not do the version with the hood.
The material is actually two pieces connected together - it actually starts to come apart at the edges if it is left raw. The other thing about it is that the waffle side is quite easy to snag and I had to be careful when cutting out as the towels had several places where they were a bit damaged that I had to avoid. But I love the material and the finish - it seems like a bit of a step up from just towelling both sides.
Thanks to everyone who has offered help - it has all been very useful!