ᐅ Renovation or new construction? Which is more cost-effective and efficient?

Hello forum members,

Here’s the situation: a former kindergarten building. The land currently belongs to the city but will be sold in a few years. I am very interested in this plot, so I roughly measured its outline using Google Maps and created a complete 3D design based on that outline. My idea is to remove the entire roof of the existing two-story building and convert that floor to create three apartments.

To start with: according to Google Maps, the building is approximately 500 m² (5,382 sq ft) in size. After deducting space for stairs and so on, about 480 m² (5,167 sq ft) would remain. Theoretically, four apartments could be created. Then, I plan to add another floor on top with the same layout as the ground floor. Since the ground floor will have terraces, I thought the first upper floor could have roof terraces, each accessible from the respective apartment. I am also considering parking, so I want to build eight garages on the north side of the building.

Now my question to you, especially the professionals: is it more reasonable to renovate and convert the existing building, or would it be cheaper and more efficient to demolish and rebuild from scratch?

Best regards, your new colleague 😀

I doubt that the structural engineering will support that.
It is questionable whether residential buildings are allowed on "municipal land for the common good." Until the property is actually sold, I wouldn’t worry too much about it.
Often, "old kindergartens" and similar buildings are repurposed as clubhouses and so on. In other words, nonprofit organizations lease or buy the land. Are you sure it will be sold into private ownership?
Is there a zoning plan or is one currently being developed? What is the surrounding neighborhood like?
Google Maps is a very unsuitable tool for surveying and planning houses,...

Hello Wastl,

Yes, it is true that this is a municipal plot, but our area is very small. Within a radius of about 1.5 meters (1 mile), there is only one bakery and one supermarket. There is also a primary school and elementary school, plus two kindergartens. Otherwise, there are no clubs or associations. A retirement home wouldn’t fit anyway, since everything is far from the next opportunity. So the city only offers it for sale to private buyers. In the neighborhood, many houses have a ground floor plus one upper floor, with an attic and a 45-degree pitched roof. There are also bungalow-style buildings on the same street, with only a ground floor. And what do you mean by the structural stability? Why do you think it wouldn’t hold up? It’s only one floor being added on top, and the roof terrace does not count as an extra floor. I estimate that my design will exceed the current building height by no more than 4 meters (13 feet).

Hello,

Denizli89 schrieb:

I am so interested in this plot that I roughly measured the outline using Google Maps and created a complete 3D plan based on this outline.

I keep learning new things 🤨

Denizli89 schrieb:

I imagined removing the roof of the single two-story building entirely and converting that floor so that it becomes three apartments...

You can imagine many things. Have you considered that the structural design of the existing building was calculated solely for its use as a kindergarten and is by no means suitable to support additional floors?

I remain curious to hear what the building authority / planning office will say about your ideas 😎

Regards, Bauexperte

Oooooppps,

I hadn’t considered that at all. The structural stability—whether the walls can support an additional floor—is a very critical issue, especially since the walls there are quite thin. So, is it better to go for a new build?

New construction is always better, and it seems you don’t have to worry about money if you want to build an 8-unit residential building without much knowledge.