ᐅ Floor plan of an accessible bungalow

Hello everyone,
we have received a preliminary design and a quote from our builder. I would like to get your opinion on it.
It is planned as an accessible bungalow (about 131 sqm (1410 sq ft)) with 3 bedrooms and possibly a study room. Previously, instead of the study, there was a slightly larger kitchen and a somewhat bigger living room.
My opinion:
I would make the house a bit narrower on the street side, which would make the bedroom and child’s room 1 slightly smaller. Instead, the living room and kitchen would be extended, allowing the kitchen to be a bit larger (it currently feels too small to me).
On the other side, I have the option to make the carport a bit wider. I am trying to achieve an internal width of 3.5 m (11.5 ft) for the carport (because of wheelchair access).
I will also ask the builder what price difference it would make to have a concrete ceiling with insulation instead of a wooden beam ceiling, a knee wall height of maybe 30 cm (12 inches), and a roof pitch of 40 degrees, so that it would be possible to convert the attic space in the future (maybe after 25–30 years).
I would like to have a carport for two cars parked in tandem with a storage room planned, but I want to handle the construction myself or have it done elsewhere. The builder is asking €14,000 for a single carport with storage, which I think is too expensive.

We would really appreciate your suggestions.
Thank you