The volume builder's offer it cheap (or standard inclusion) because they bargain down the supplier and installer who will be suppling many (i.e.: volume) bench tops of pretty much the same size and specification..... Custom designed/bespoke/renovation dwelling's cost so much more because they're 'one off' rather than the same design being built many times over.

Thank you everyone for your responses. I’m still undecided - I have a few weeks to consider what to do. The bench top salesperson showed me some photos of the few people who have added a small amount of benchtop stone to add some height (and it’s always because of a busy 60 x 30 patterned tile that the owners want to keep perfect) and in her words it looks ‘dicky’. Not least because the tile sits flatter against the wall than a 2cm thick slab of benchtop. It leaves a pronounced lip of 1.5cm where tile meets benchtop addition Then there’s the safety concerns mentioned above about flames near stone which I had not considered. Big reader - I love your maths but I’m only 150cm tall. Even with a low bench and oven height of 94cm (my oven’s lowest height setting) plus 70cm of tile between the bench and overheads, the cupboards are already 14cm above my head. This barely makes them usable for me even now! Adding another 15cm instead of the 10cm, while looking lovely and keeping the pattern intact, means my short-arse self will have real difficulty reaching anything safely. Every cm counts when you’re short! But I do appreciate your input!

I have timber on island and laminate on rest and am happy with that. Would need to tonal,y match so it is your choice of timber or stain.

Hi there we went with a glass splashback in Haynes Minimalist #1. I can DM photo if you like? Learning for me is that the colour sample tile does not take into account a finished room, flooring, lighting, natural light etc. as glass is so reflective. I found it very difficult to find a glass colour that suited both the stone and cabinet. Cheers