Thank you everyone, your thoughtful advice was very welcome. I'm attaching a photo as its all finished. I selected Olive Reserve for the splash back and painted the wall above it the same colour. As its a big room with lots of light and a large window it doesn't dominate. The glass is so easy to keep clean and I love the way it reflects the garden and light. Have to say though some people are stunned into silence when they see it, but as the cupboards and bench tops are quite bland I knew something bright was needed

There is no specific regulation but it would not be recommended behind a gas cook top. If there is a concern you could install the timber behind a glass splash back for protection. There is also a really nice tile that looks exactly like timber as another option.

Hi Lorza101, You're kitchen looks lovely! The white cabinets will really brighten the space and when combined with an oak floor, will not be stark. Timber is always a good way to add warmth - though this can be done using large chopping boards (particularly round ones leaning against the splash back) and other accessories. I'm only reluctant with timber bench tops around sink areas. If you go with a dark stone top, try to tie it in with your splash back, possibly through tiles. If you like patterned tiles, this is an opportunity, though avoid encaustic tiles, as these are too porous for a kitchen splash back. Is your overhang 400mm on the long side for seating? If it is 40mm, I would think a 20mm stone top will be fine, though at 400mm I would take the advice of the stone guys and go with a 30mm top, particularly as it won't be supported with waterfall ends. Good luck with the rest of your renovation. Cathy

The rangehood looks rather disjointed from the whole look - did it come with a flue extension that could go up to the ceiling? I don't know if it's because it doesn't have top cupboards near it as well that adds to the problem, so if you tiled up to the rangehood and put the floating shelves just above the tiles like in the pictures in the last post, it might help to visually join everything together.