ᐅ Existing house floor plan with two residential units and an extension

Hello dear forum,

I am new here and have spent last week reading through many discussions about "building planning" and "floor plans."

My sister and I are planning to convert our family home into a two-unit house (after careful consideration).

The house was designed and built by our grandmother in 1967. Our parents took over in the 1990s.

It is a very large house and has been manageable so far, but few major investments have been made. It still has the original roof, the first windows, and heating and hot water are oil-based.

Since my sister and I are very attached to the house, we have decided to invest and adapt it for two households.

Due to the emotional value, a new build is ruled out. Both households plan for two children each, so there would be eight people living in this house in total (assuming life doesn’t throw us any curveballs).

An extension would only be possible on the north side.

The first floor plan drafts are available. Since we both have little building experience, we rely on the architect and other external consultants.

I would be really grateful if someone here might have the time and interest to take a look at the initial floor plans and provide comments or feedback.

At the moment, we are in talks with the architect and various tradespeople (window installer, master carpenter (roof/dormers/extension), heating engineer) to get a clear overview of the entire construction project.

About the floor plans:

• We are aware that the right unit has many bathrooms (this is due to the current layout).
• Left unit: kitchen and dining would be in the extension.
• The garage will be shared by both units.
• Ground floor: the entrance area and laundry would be assigned to the right unit. Access to the garage for the left unit would likely be from the outside to ensure two separate living units.
• Upper floor left unit: laundry/ironing/study is currently one large room, which would probably remain as is, and we would most likely turn it into the master bedroom.

Less ideal:

• The loggia on the upper floor, belonging to the left unit’s rooms, would be above the right unit’s terrace. It might be possible to omit this external access.
• The dressing room on the upper floor is currently assigned to the left unit but could also be allocated to the right.
• Both units currently lack a dedicated workspace. This could possibly be integrated into the guest area.
• The left unit has a bathroom upstairs and a guest toilet downstairs. The right unit has a total of three bathrooms and one guest toilet.

Maybe you have additional feedback for us.

Thank you very much in advance!

Attached are the “old/current” floor plans as well as the new ones.