Just a quick response to your layout and proposed ideas. Moving the sink to the end of kitchen could be OK. The waste pipe would go horizontally behind the base units in the service gap that most units have (except Ikea units). Then outside to join back onto existing drainage. Personally I would leave the sink as is. If you really want to add more base units under the window and do not want to do any wall removal then the cooker could stay on the same wall as it is. Just nudge it along and reduce the existing draw unit to the left of the cooker to a 300mm Then maybe a 150mm unit to the right before the new corner. If you did fancy taking down the wall and replacing the Range cooker. Then I would recommend a down draft induction hob with built in extractor. I've specified Bora hobs with great success in the past. https://www.bora.com/gb/gb/cooktop-extractor/bora-basic/ More storage could be had at the other end of the kitchen with a couple of tall larder units. Maybe reduce the depth of the stand alone unit in the far corner so its not to overpowering. Next real step is to find yourself an independent designer and arrange for them to visit and run through your options. Happy designing.

Daisy I don’t know if you remember my previous posts on sinks and worktops? I think I’m going to go with Quartz worktop (gulp ££££) but I’m still dithering over the sink. I have a white ceramic sink which is now 10 years old. It hasn’t aged well. Firstly, the plug started leaking, draining out the water. We bought a replacement and that leaks too. Because of this we’ve had to use a washing up bowl (hate them!) which has added to the scratches at the bottom. Even after a good scrub with bleach it looks a mess. That’s my experience, but they do look lovely when new! I think I’ll go for under mounted stainless next time. Here’s a pic of mine now.

What is the builder's reasoning? Doesn't really make a lot of sense IMHO! I've had a Franke white undermounted sink for years which has been fab, but does get grubby - it needs a regular bleach to keep it looking nice, which I'd rather not do for environmental reasons. In our new kitchen and utlity we're having Franke undermounted brushed steel sinks which I'm hoping will be easier to keep clean. The kitchen one went in yesterday and feels really nice and sturdy. I think sinks are important in a kitchen and therefore worth spending the most you can afford - they are workhorses, and you don't want a flimsy workhorse! With undermount you do need to pay a bit of attention to cleaning the bit under the rim of the worktop, but that applies to cheap or expensive!

Are you having a boiling water tap? lf so don’t have a ceramic sink as they are prone to cracking. I have a stainless steel. Easy to clean. Just one large bowl in mine. l do have drainer grooves, but they’re not effective.