Re the layout - I didn’t think there would be much space in front of the WM if I had them all across the back. Seemed a bit cramped and can’t bend over to get to things? Maybe not - will have to have a think on that! It’s not the concrete outside that was an issue as that was all dug up for drains to go in and has now been put back. I think it was on the other side of the wall in the floor? So if they put the pipe under the floor, the wall there was too thick to core out. He was at it for some time and gave up, ha ha. Will re investigate though! Re radiator - I put one there (standard rad and not a towel warmer) because ... there is no heating that side of the kitchen at all and the small one puts out quite a lot of heat. So we could leave the sliding door open to keep that area warm (and especially in winter if the dogs sleep in that room) That was it really. Why wouldn’t it work there though? The thickness of it?

In your kitchen plan the space between the wall run and the island is massive - maybe 1.3 or 1.4m? It should be more like 1m otherwise you will find the two surfaces are inconveniently far apart. That also means there is more space for a dining table than it looks like from your plans. Do you have a cellar? If not then the understairs space is available for a WC, you might need to carve a small corner out of the kitchen to add to the understairs space depending on its size. Or if you do have a cellar the wc can go where Jonathan has put it (entrance can be from the understairs area if you have the height, or from the kitchen if not). Is there somewhere upstairs you could put a laundry room/area? In or near a bathroom perhaps?

For option 2 , I would get rid of the sink or at least get a much smaller sink (maybe a mini butler) in the 2nd plan. It takes up far too much space. Alternatively, you could move the sink to the opposite wall. Either way it makes the utility room really cramped. Especially if you're trying to fit a boiler, sink, stacked units, cleaning products and a radiator in there. Is there a separate door to the toilet? Option 1 gives you a bit more wiggle room to fit all the items you want inside. You'd lose about a meter from the garage but I think it'd be worth it. If the door swung outward or a pocket door was installed, you could have a mini corner sink in the toilet. Go for a narrow width door in either situation 680mm.

We're just fitting this one in our small utility cupboard. https://www.diy.com/departments/cooke-lewis-sagan-polished-inox-stainless-steel-1-bowl-sink-drainer/1310477_BQ.prd  It's not the prettiest or most designer sink but I wanted a small drainer and have also bought a small basket drainer to keep in the sink as needed. I wanted some space to soak items of clothing, clean paint brushes, wash stuff I want to keep away from the main kitchen area.