You have a wonderful opportunity to get what you want but your floor area looks very narrow, you might want to see how much space you need to access your washer and tumble dryer and how much space for folding sheets. Do you need all those doors if you have one into the kitchen and having the external door opening outwards would give you more space. Also to get rid of the corridor effect, you might want to think about moving the unit to left of utility entrance. Depending on your vacuum cleaner, you might be able to get away with a narrower unit than the standard 600. If you haven't already done so, it is worth measuring the cube of the equipment that you need to store. Hope this helps, good luck.

Much better layout and use of space. You need to work out “what do you want in your utility room?” I have a single run of work surface with cupboards over it. It houses the boiler in one of the cupboards but all manner of junk in the others! Underneath the worksurface I have a freezer, a wine cooler, and two washer / dryers. These are all in one row. By NOT having a return on the work surface I have a back door into the utility room. You could do the same and therefore your problem is resolved. If you were to move your doorway of the utility room onto the other wall you could have the return on your worksurface if you wanted it, or you could use that wall as shoe storage. Instead of a door you could have an open archway, as I have, making the room more spacious and accessible to the kitchen. Our dog sleeps in the utility room and we use a foldaway stair gate to keep him in, so easy access to the room during the day, when we need it, but able to lock him in at night when we want to. We also have a dog flap in the utility door so the dog has access to the garden whenever he wants, a very useful feature!

I’m confused about the layout. It looks like the entrance is directly into the kitchen area. Perhaps it would be useful to create a hall with storage. This then also means there is no access to the garden- would French doors from the lounge be useful? You say there are table in both rooms and the space is crowded. Presumably the plan is to reduce to one table- would you actually have to take down a wall to make that change? It seems like your parents are short of living space. Of course an extension would help but perhaps there are other possibilities such as converting the smaller bedroom into a full downstairs bathroom with laundry facilities. The cloakroom could be a new entrance in order to free up space in the kitchen area and create more space for dining. Since you are likely going to do some work to the house consider if there are things you could do now to future proof it. This means a walk in shower and a comfort height toilet, a raised washer and dryer, an eye level oven, door handles rather than knobs, innovative pull outs to make access to wardrobes and kitchen cabinets easier. If they don’t already use it consider smartening up the larger of the two downstairs bedrooms so it’s inviting rather than an inevitability. You might also consider outside lighting for security, relaying uneven patios to remove trip hazards, an electric garage door etc. And if your only concern about an open plan arrangement is cooking smells consider a really great extractor such as a Bora cooktop extractor.

thanks everyone for the suggestions. unfortunately the width on these rooms has now gone down to 1.8m instead of the 2.1m shown on the drawings so having a corridor in that space would leave us less than 1m to play with for 1 of those rooms. looking to utilise space from the toy/home office below. any suggestions welcome thanks