What about putting the two bedrooms next to each other/in line at the front but then creating a light well (see our beversbrook road project) next to the bathroom to light the second bedroom. Then the kitchen diner could sit full width across the back of the house with nice big doors to the garden/courtyard.

I see what you mean with a courtyard bit? the courtyard felt like it would take up too much space. I suggested a large skylight in the bedroom also but I understand your not allowed just a skylight in bedrooms due to fire access? this is the design I had suggested instead of a courtyard (attached) is there a way to do this without the courtyard?

Do you have a second floor (and floorplan)?

And I assume this is a terrace without any space on the sides? (long plot)

Looking at the measurements looks like you have almost 6 meters out to the rear and say the width is 5 meters wide now that space i quiet large space you can easily fit kitchen with skylights above it, would recommend flat roof(gives you a nice square room) but if you can not get it approved the pitched is fine too it means ceiling will be half vaulted to the left but towards the rear you can have a flat roof. All open plan play area, kitchen, living and dining possibly kitchen island fitted too. In this areas you also fit your services such as combi and systems this all can be built in part of the kitchen.

This will then allow you to have the existing areas reconfigured, using RSJ steels technology for support will help you achieve this, usual place for your bathroom would be under the stairs

and towards your left you can have a bedroom and maybe another formal living room area? this can all be part of the hallway so the kitchen area is separate to your entrance and hallway area basically existing house.

Hopefully we gave you some ideas.

Is 6 meters the maximum you can extend? Would it be an option to start your extension behind the current bathroom? How (deep) is your plot? Any chance for a two storey extension?

I would agree with the Architects here. The most important thing is creating a good quality space. Maximising your area is a good move as long as the quality does not fall. It is tough when there are options available, however make sure you are 100% happy with whatever you decide as you will have to live with it. Let us know if you need any help.

And I see only the single bedroom in your blue colored plan. No more double bed downstairs? Personally I like to keep my kid close, in case of emergency. Would never ever want a kitchen inbetween me and his room.

Still curious what your second floor looks like.

Your architect should check out all the legal/technical details for you but if the light well is too small there simply won't be enough of it to get much light and air or room for plants. I would say the one at Beversbrook road is about the minimum size.

Off the top of my head the Beversbrook space is just under 2m x2m

Could you post a photo of the back and the garden? Two bedrooms in the back would be ideal in width, but then you'd have to go through a bedroom to reach the garden, thus not ideal..