Extension Design - input/advice/suggestions please!

Hi all.

Wondering if there would be an appetite for reviewing & comment on our design for an extension we are planning. I should point out that we are meeting architect to work on drawings, but this is our preferred option before we do so.

It's a 1920's red brick, end of terrace with a garage on the gable end (west). Sitting & dining rooms 10ft ceilings. I've tried to sketch to scale, attached current.png is the layout. The following is what we're trying to achieve:

- bigger kitchen (does not need to be massive)
- utility room
- ideally an additional room to be used as office/snug/den for kids
- upstairs en-suite and walk-in wardrobe

We're planning to knock the garage, and build 2 storey extension accessed on ground floor by knocking the wall in the dining room, see extension.png for GF layout. The upstairs en-suite and walk-in wardrobe are accessed by knocking an opening from the front (master) bedroom.

We like the idea of having a south facing front patio, where the garage doors were we'd put up some sort of wooden fence to make it private and plant heavily.

We'll split the current kitchen on the return into a study (off the new open plan kitchen/dining), and a utility room (plumbing already on the north wall).

We'll also block access to the return from the hallway to allow us to build storage into hallway section. We could adapt this to include a hall facing cloakroom, and storage accessed via sthe den.

We don't use the garage for much apart from bikes, washer/dryer, garden stuff and some storage. So we'd build a small well designed shed in the North East corner of the garden to store garden things etc, and remove the flowerbed in the front to make way for a bike store. The washer dryer would go in the utility section of the return.

I'm pretty confident that the option we're taking is the only option that ticks all our requirements, but I'd welcome input.

I would particularly welcome advice into open plan area, including:

- kitchen layout: we don't want to build any bigger than we really need, so how far out should we go & how wide does it "need" to be?
- Considerations I suppose are that the units will all be on the west wall, and that we'd like enough room for a large island & kitchen table. I think about 3.5 to 4 metres east/west and 6 metres north/south would be good for the actual extension element.
- there is a height difference between garage and dinging room, I think it would be best to bring up the level of the extension so the floor & ceiling are flush, we still have 10ft ceilings
- I like the idea of a floating ceiling, do you think this could work?

Sorry for the long post, hope some creative types have the time to read & respond. Thanks!