I'd do exactly as Jonathan has done on the ground floor. The first floor can be re-configred in a miriad of ways depending on whom you wish to afford it to ie;- The boys and the Nanny, I'd still try for 3 bed, and En-Suite and a main bathroom. I think that whomever is using it, then you'll need an En-Suite either for yourselves or your Nanny. So something like this may work well. The loft is a whole different kettle of fish. 2 metres is okay - you can stand up in there. I'd certainly get rid of the pointless utility room and turn it over to storage as you have 3 boys, you're bound to need quite a bit. It's possible that you could re-arrange the entrance slightly and donate the long thin area over to a playroom, giving them more space to play indoors.

Thank-you very much for the comments. I hope it will be a great space, but playing around with it and changing the design at the last minute is getting a bit stressful! This is the design that the build company showed us initially - just their initial thought as it how it would look. I found feeling the area where they had positioned the fridge/freezer very tricky. We want a free-standing french larder style fridge and the doors and level of matching with the rest of the units didn't seem like a good fit. The support pillar for the steel that crosses the island in the attachment below has also been a real annoyance. It sticks out 23cm, so it can only really go through empty-ish cupboards. Clearly anything to the left of that steel is difficult to vent. On the design in my intitial post, I was intending to have a dropped ceiling element that stretched just beyond the steel. This would let me have a powerful extractor and exit the flew onto the flat room (hidden by the drop ceiling 'box'). I like the idea you describe of a full wall of units, then island, then table. I guess Jonathan's proposal is similar to that. While I love the efficiency of the "4 double door" hideaway I just don't like the aesthetic, so will need to think about something else. Bringing it back to what we need... Utility room: enough to stash the washing machine, store the vacuum cleaner and hang a few clothes. No need for a sink. Free Standing, 90cm wide fridge, nicely framed either by wall of kitchen units. Waist height oven with an additional "top oven / grill (broiler)" - so at least one full height column. Good size kitchen island with at least two seats. Approx 90cm induction hob, plus a gas domino hob. Powerful, externally venting extractor over hob. I'm relatively open to moving the kitchen/living area to wherever it works best. I'm also not desperate to have the hob on the island (but that would be nice). As far as I know, the builders haven't done anything that can't be easily adjusted at this stage - but I think that will change in a couple of days - and they are planning for the kitchen to be in the old part of the house. As for rooflights - I thought, perhaps wrongly, that it would be light enough with the big bifold doors. It is an east facing room, and the old room had some sliding paitio doors and it felt bright enough. So I have left roof lights out on the basis that - but I'm also concerned about noise. (Cheaper too!). The biggest window we can gave without incurring significantly more cost is 1800mm x 1000mm - I'm minded to be 2 or 3 of these in that middle section. Thanks!

Thanks for your comments! The first plan has general dimensions but until we get the keys thats all we’re working with unfortunately. Yes definitely agree with you that the new extension will have space for a dining table, just wanted to mention that we personally will be using it as a lounge space 🥰 We’ve done so much research on similar properties so understand what we need in the space to get the most value partiucularly within our local market, it’s just a matter of working out the best means to achieve it. I think I forgot to mention that the house is essentially derelict so the old extension needs to come down in place of a new one and everything internally (including plumbing and electrics) need to be replaced so we have a blank canvas!! Really appreciate you sharing your thoughts!

Love the catflap in your internal door! I see what you mean about the door opposite the fireplace but it can be overcome. How many people do you need to seat? This style of room lends itself to a tv watching area maybe with an L shaped sofa and a supplementary armchair and the other end could be two armchairs with a bookshelf or sideboard against the right hand wall. If the door really bothers you, you could change it to sliding as there is room. You might have to move it up or down slightly. With nearly 5m across you should have room for the sofa and the door to open behind it.