ᐅ Floor Plan Design for a 170 sqm Bungalow

Hello everyone,

We reserved a plot of land 8 weeks ago and started working on the floor plan. After a few days, we found an initial design that we generally like. Not everything is exactly how we imagine it yet, but I think we are on the right track.

Here is the questionnaire:

Development Plan / Restrictions
Plot size: 819m² (8,813 sq ft)
Slope: no
Site coverage ratio: 0.4 (allowable exceedance 25 per 100), so 0.5? -> This only applies to auxiliary buildings, right?
Floor area ratio (FAR): 0.6
2 full floors
Building envelope, building line and boundary: approx. 13m x 25m (after southeast enough space), see drawing
Minimum garage distance from the street is 5m (16 ft)
Roof type: gable, hip roof

Homeowners’ Requirements
We would like a large bungalow with a hip roof, which fits the development plan. We plan to build without a basement but want a storage room on the property. The roof structure should allow for future expansion. The attic shall be used for storage initially and later as a playroom for the children (storing a slot car track, table football, etc.). We are 4 persons: child 1 is 6 months old, child 2 is 2.5 years old, my wife (35) and I (37). Our family planning is complete. One of the rooms must serve as an office since I work from home. My wife shares the office with me, so it can be a bit larger. We prioritize a single-level design and sufficiently large rooms.

Space requirements: approx. 140m² (1,507 sq ft) net living space excluding circulation and utility room; (gross about 175m² (1,883 sq ft))
Office: for family use and home office
1 overnight guest per year, so no guest room needed
open floor plan
open kitchen with island
dining area for 4 (one dining space)
no fireplace!
terrace yes!
double garage and later 1 to 2 outdoor parking spaces

House Design
Who created the design:
- Designer from a construction company

What do you particularly like?
Nice living/dining area with kitchen and transition to the terrace.

What do you dislike and why?
Hallway / circulation area very large. It should be even larger if a staircase to the attic is planned in the entrance or rear area in front of the children's room.

Price estimate per designer: $216,000
Personal price limit for the house including fittings: $260,000
Preferred heating system: geothermal heat pump

If you had to give up something, which details or expansions
- could you give up: possibility of attic expansion, smaller bedroom would be okay
- could you not give up: everything else

Why is the design like it is now? For example,
Design created by the planner after several planning attempts and adjustments

What is the most important/basic question regarding the floor plan in 130 characters?
Are there other floor plans that meet our needs? (Alternatives) Is there enough space in the bathroom for a walk-in (barrier-free) shower? Is the office too narrow? (3.11 x 6.59m (10 x 21.6 ft)) If the attic is to be converted, where could a staircase be placed? Current design is 13m x 16.7m (43 x 55 ft). Would extending it to 13m x 17.7m (43 x 58 ft) affect the appearance negatively? I think it would look too stretched to the rear.