ᐅ Large single-family house with 4 children’s bedrooms – adaptable into 2 separate living units

Hello everyone,

we are planning a larger house to eventually accommodate four children, with the option for grandparents to move in later. Since the space requirement won’t be this high permanently, the house should be divisible into two separate living units – for example, for subletting, for an adult child with family (as we ourselves grew up), or for flexible use and better resale value. My parents live on the neighboring property to the north; we are trying to respect that (they want to stay there but are still independent).

I welcome honest, well-reasoned feedback – the more detailed, the better.

Plot and framework conditions

• Location: infill development, no formal building plan → orientation based on heterogeneous surrounding buildings
• Plot size: approx. 740 m² (about 8,000 sq ft), slightly elevated (approx. 1 m (3 ft)) compared to the street, then level
• Site coverage ratio: 0.4
• Floor area ratio: not specified, 2 full stories typical in the area
• Setbacks: 3 m (10 ft) to neighbors, up to 6 m (20 ft) at property boundary possible
• Edge development: only carports allowed
• Parking spaces: 2 required (driveway counts as second space)
• Roof type: pitched roof 23°, allowed range 20–45°
• Neighboring houses: height 7.8–9.2 m (26–30 ft) → planned building 8.81 m (29 ft)
• Orientation: street to the east, entrance planned to the north

Client requirements

• Style: efficient rectangular volume with pitched roof, flexible in appearance
• Basement: no (too many rooms that don't fit well in a basement)
• Stories: 2 plus attic for storage
• Residents: currently 2 adults, 2 children → eventually 4 children plus possibly grandparents
• Space needs: 4 children's bedrooms, 1 home office, 1 guest/grandparents’ room, kitchen, living area, utility/technical room, sufficient storage
• Kitchen: open plan with island, seating for 6–8
• Fireplace: no
• Balcony/terrace: no upper terrace, focus on garden
• Garage/carport: carport
• Kitchen garden: present but not a priority
• Size: preferably under 200 m² (approx. 2,150 sq ft) living space (tax benefits, lower running costs)
• Goal: position house as far south as possible so parents’ house to the south still gets sunlight

Design status

• Planning: done by independent planner for a fixed price → to serve as a basis for builder offers
• Current status: mostly final, last optimization round planned

What we like

• Room layout meets all requirements
• Utility room right next to bathroom (laundry without stairs)
• Large, bright open kitchen with plenty of storage
• Attic compensates for no basement
• Good size children’s bedrooms
• Overall efficient floor plan

What is still not ideal

• Hallway width (1.25 m (4 ft)) is rather tight
• Minor compromises in furnishing, but overall satisfied

Budget

• Planner’s estimate: 550–600 thousand euros (outdated)
• Our expectation: about 650 thousand euros
• Upper limit: 700–750 thousand euros
• Heating system: heat pump with underfloor heating

Priorities

• Essential: 4 children’s bedrooms
• Dispensable: some space or number of windows if necessary

Design development
We planned ourselves for a long time before hiring a professional planner. The process was an iterative one with back and forth optimization.

Furnishing
The living room still needs a large sofa and a TV on a shelf. The large wardrobes in the rooms probably won’t be that long; instead, desks will go there, for example. The bed likely won’t be in the home office. The kitchen island contains the stove and sink with a worktop between, and storage areas at the edge.

Special features
If the wall between the two western children’s bedrooms is removed, a full 4-room apartment is created on the upper floor (open kitchen/living area + three rooms + 2 bathrooms). The division would then be, for example, along the red lines shown. This greatly increases flexibility – for a granny flat, rental, or grown-up children later on. Even in the worst case (sale), the floor plan remains value-stable and versatile. Overall, the house feels like a very efficient realization of a large program of space – but we are open to any well-founded criticism or improvement ideas.

Specific questions:

• Floor-to-ceiling window in the bedroom or not (possibly desk space)?
• Is the small window in the upper hallway sufficient?
• Would an additional south-facing window for the children’s bedrooms on the south side be useful?
• The house is positioned quite close to the southern boundary – is that reasonable from your perspective (considering parents’ house to the south)?
• Utility room directly adjacent to the bathroom with prepared connections for a washing machine enabling possible separation of living units – practical like this?
• Should the wall between living room and kitchen be optionally designed as non-load-bearing? Likely costs around 5,000 euros more.

We look forward to comments on:

• Room layout
• Lighting/orientation
• Proportions/furnishability/daily usability
• Rental potential and value development
• Anything else you find relevant

Thanks for your input!

[ATTACH alt="Bildschirmfoto 2025-10-05 um 00.52.59.png"]93026[/ATTACH]

[ATTACH alt="hausansicht-einfamilienhaus-mit-pv-anlage-baum-bank-hund.jpg"]93029[/ATTACH]
[ATTACH alt="hausansicht-einfamilienhaus-mit-pv-anlage-baum-bank-hund.jpg"]93029[/ATTACH]
[ATTACH alt="Bildschirmfoto 2025-10-05 um 00.47.06.png"]93027[/ATTACH]