Enlarge and fully renovate a single-family house or demolish and rebuild?

Hello everyone,

the following situation:

We can get a plot of land (600sqm) with a house from the 60s with 105sqm of living space on 2 floors for €150,000. The land value (standard land price) alone is €130,000.

However, the house is too small for us. We would like to implement the following measures (the development plan allows everything):

1. Extend the house 3 meters to the back and 3 meters to the side.

2. Add floors.

3. New roof.

4. New exterior facade.

5. Complete interior renovation.

In other words: We basically want to redo everything.

Can this be worthwhile, or does demolition and new construction make more sense? Are there any tips for funding (KFW) etc.?

Please excuse me, but I am (still) an absolute beginner. I know that no cost estimates can be given here. But maybe there are people who have undertaken a similar project ;)

I am grateful for any information.

That cannot be profitable. A new building is most likely the significantly more economical solution.

1. Increase the house by 3 meters to the rear and 3 meters to the side.

You can't just widen a house by 3 meters. The old walls have to remain. At most, an extension is possible.

2. Increase the number of floors

Everything above one floor that is increased gets removed. So actually a new building.

Can this be worthwhile, or does a demolition and new construction make more sense?

You actually don't want to preserve anything. So demolition and new construction is clearly easier.

But maybe there are people who have undertaken a similar endeavor

Several, just in this forum. But more qualified information would be needed, especially since the 1960s were three decades when it comes to construction technology. Provide the exact year of construction, show photos, floor plans as-is and to-be, and also a section.

I am renovating a house, somewhat older (1914) on which the last work was done around the 60s (electrics, plumbing, the heating again at the beginning of the 80s). Everything is being redone except for the walls and the roof (renovated in 2010 due to an insurance case). The costs are at the level of a comparable new build (about 3000€/m2). If the house were not under [Denkmalschutz], demolition and new construction would have been the logical answer! Especially since then you would no longer have to make compromises in the room layout and orientation.

In other words: It feels like we want to do everything new.

Then you should do exactly that - demolition and new construction. In the case of a pure structural renovation, I would recommend preserving the existing building. But with extensions, etc., it will probably end up being more expensive than new construction.