Yes of course - the unit was custom built for Tregoose by a company called Cheverell Wood. They're based in Devizes and did all the woodwork in the house, including all the vanity units, the kitchen, bar, wardrobes and built in beds. Here's a link to their website: https://cheverell.co.uk/ I hope that helps!

Thanks so much for taking the time to reply. I think bespoke seems to be the only way to go!

I was looking for something similar and came across Parker Howley online - they seem to do similar designs...
https://www.parkerhowleynco.co.uk/bathroom/

Sarah U-S, thanks a million. I was starting to think vanity units with drawers and a shelf rather than just a cupboard was a mythical item in the UK! All the pics I like with this design seem to come for the US or Australia for some reason (having viewed what feels like every bathroom showroom in the SW of England there is a real lack of diversity in design here).