Dear dobbelhaus, don’t take it the wrong way, but a lot of people here are sharing their thoughts with you. All of them are people who deal with houses, floor plans, and site plans either as a hobby or professionally. The vast majority consider your previous ideas immature, and it’s not just about moving a wall a few centimeters to the left or right. Essentially, you can do whatever you want with your money – but you are asking for advice and you’re getting it here – for free! When I first showed up here with the initial designs for a semi-detached house project for rental purposes, there was also a lot of criticism and many thought-provoking ideas – especially the analysis of potential tenants and which tenant group I wanted to have in my house.
When I apply what I have learned to your house, I come to the following conclusion:
Apartment on the ground floor: 3 rooms with garden, singles or couples don’t need the garden, might find it nice but will be annoyed by the paths around the garden. Probably a family with one child would move into this apartment, who cannot afford a bigger flat – and would move out when there is a second child.
Apartment on the upper floor/attic: 4 rooms, narrow balcony (not enough for a deck chair or dining table), garden on the east side of the house (shade in the evening). Families won’t like the stairs to the garden; they would prefer a terraced house with similar size. To a well-paid couple, the east garden is useless because it’s in the shade of the house in the evening. Nothing can be placed on the nice sunny balcony, the rooms in the attic hardly offer any added value. Also, the question arises whether there are such yuppies at the building location? It is definitely a small town with good connections, but more a place where families or average earners live – the yuppies take the maisonette penthouse in the city center.
Hence the idea to divide a semi-detached house into 3 small apartments, one per floor. This might better fit the demand of the town and would have no difficult stair solution that every maisonette concept brings – so the potential later private half could be realized even better.
Perhaps as a last food for thought, here we have companies that act both as developers for apartment buildings, semi-detached houses, terraced houses as well as general contractors. For a project of this size it might be possible to get such a company on board as a GC and as a consultant regarding local demand.
Your house will easily exceed a million, probably rather 1.5 - 2 million in total. Professional project consulting would not be something I would save on.
Our architect is about 60 years old, a graduate engineer, a sworn expert, and has built a few thousand apartments and houses; his wife manages houses, daughter is a real estate agent. The family business owns dozens of rental houses and apartments and knows the city well and I have noticed everyone involved in construction in the city knows the family. I would not get better advice anywhere else. The idea of a semi-detached house with 4 apartments comes from the architect, originally I only wanted to build a semi-detached house. He explained the reasons to me and quickly convinced me. So much for that..
But here there are many practical tips and suggestions for me that are very helpful but unfortunately also a lot of nonsense, as is usual in internet forums.
You can look for floor plan ideas here but not conceptual solutions for a rental property, which depend on many factors. Nobody knows my city here, nor the town where the house is being built, the purchasing power, current rental situation, rent index, types of families who want to live here, and so on and so forth.