Bungalow floor plan design - ideas?

Then separate office and storage, with its own outside door. Then Schäuble can pay for it.....

Hello Yvonne

The toilet in the storage room is great: can you even still enter it when it's furnished?

Basically, the design might work if a wardrobe is still planned there. After all, this design did not reinvent the bungalow - it's just a series of rooms lined up.
It's good that the children have their peace "up there."
It's bad that the open-plan kitchen is more like a very dark cave and can feel very uncomfortable as a passage room with three doors.

You can do much more with a bungalow than a simple dark long corridor layout, which is accessed through a narrow vestibule.
I don’t like the house.

Regards, Yvonne

Bad that the open-plan kitchen feels more like a very dark cave and can seem very uninviting as a passage room with 3 doors.

That one high-set window alone really doesn't make much light – you could add skylights, but that wouldn't be optimal. Overall, the living-dining area still seems to have a lot of potential for improvement. If one of the French doors already hits the sofa in the drawing, it won't be any better in reality. Also, the ratio (both in room layout and area) between living and cooking/eating still seems a bit off to me.

The toilet in the storage room is great: can it even be furnished and still accessible?

This room also has a door to the outside. In my mischievous daydream, I see a film where a Herbalife representative wants a customer and staff toilet for his "farm shop," well separated from the private part of the house. That seems simple yet cleverly solved to me.

What is clever about that, ? Two walls in a storage room enclose a mini-room, called a WC, which would not be conveniently accessible for guests. If there was at least a connection to the living area, one could still work on the size so that it would be worthwhile to invest costs in a third WC.

I’ll make a suggestion: to start planning fundamentally anew. Possibly move the bay window upwards to create a southwest courtyard and allow the rooms to benefit from the light. By planning a children’s bathroom, one could arrange the children's rooms on one side and the parents’ wing on the other. Storage room close to the guest room with a toilet that could possibly serve as a connection so both areas benefit from it. Better structured living kitchen with a large south-facing front. The parents’ wing could then also be placed nicely “behind” the living room.

Best regards, Yvonne

What is clever about that, ? Two walls in a storage room limit a tiny room, called a WC, which wouldn’t be conveniently accessible for guests. If there were at least a connection to the living area, one could still work on the size so that it’s even worth investing costs in a third WC.

I would rather let private guests use the private toilet than build a fourth toilet just to separate private guests and occasional business toilet users (customers, sales or packaging or inventory helpers). Giving these two "foreign" user groups their "own" toilets is less important to me than keeping customers out of the private area.

Of course, one could also place the utility room in the corner and attach the guest WC to the vestibule. At first glance, that would be the solution that avoids an additional toilet just by changing the room arrangement. But then the business area would be the passage area, which is tax-disadvantageous. As drawn, I find it better solved there.

The parents' wing could then also be placed nicely "behind" the living room.

With the consequence of turning the roof shape from an "L" to a "T," right?

In terms of appeal, that wouldn’t be my house, but I only deduct points – though clearly – giving an overall grade of "three," due to the still clearly optimizable living-dining-cooking area.

I would rather let the private guests use the private toilet than build a fourth toilet just to separate private guests and occasional business toilet users (customers, sales or packaging or inventory helpers).

I am not talking about a 4th toilet in my post!

With the consequence of turning the roof shape from an "L" into a "T", right?

No, I am even staying with the basic dimensions of the L – a projection is not necessarily needed on the north side.
To explain: I am talking about a completely different floor plan.
Something like

Of course, you could also place the HAR in the corner and attach the guest WC to the entrance area.

does not improve the flaws of this floor plan in any way.

Ultimately, it is pointless to worry about this toilet room if the OP does not explain why this or that has to be the way it is.
Business, trade... all well and good. But why this room? Why this storage room in the south? Why the children’s rooms in the north?