Hi @Lottle do you mind offering pointers to another clueless person too please? 
Our kitchen hasn't even been built yet as it is also in a new rear extension... all I know so far is that it will hopefully be a 5.4 m x 3.7 m rectangle (internally).
Facing down the garden with the 5.4 m wall at the back of the extension, it will be south-facing, with one/two windows in that wall and French doors in the left hand 3.7 m wall somewhere.
The door into the kitchen will be on the left hand side of opposite 5.4 m wall, which backs onto the new bathroom and leads off a hallway (created from existing cloakroom plus space outside the new bathroom).
Our plan is to have the main water supply coming into the right hand corner of new kitchen, on right hand 3.7 m wall, near to bathroom for easy access, and to have the gas coming in there too, so the boiler and gas hob/oven/range (?) will be on that wall.
The sink, dishwasher, washing machine, and tumble drier will hopefully all be along the back 5.4 m wall/in the peninsular bit, with water supply under new floor/behind cabinets. Drainage exits under left hand side 3.7 m wall to join up with new bathroom drainage.
I am looking at either an L-shaped kitchen, or a peninsular/G-shaped kitchen in the right hand half of the rectangle, with enough space for a 6-seater table and chairs in the left hand half/what's left of the kitchen, and to be able to access the French doors leading onto the patio...
Oh, and if possible I'd like to fit an American-style double door fridge-freezer in there somewhere - but it won't need a water connection as it won't have an ice maker!
I think that's as far as I've got so far... and I'm looking at DIY lichens and self-fitting the cabinets, and either self-fitting a laminate worktop or getting a granite worktop from DIY kitchens if the (small!) budget allows . Any pointers would be great, thank you 
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