ᐅ Demolition of Single-Family House, Land Subdivision, and New Construction

Hello dear forum members,

I am currently considering purchasing a plot of land of about 1000 sqm (10760 sq ft), including an existing building. The house, built in 1970, is a prefabricated house and, in my opinion, it is no longer worth renovating.
I am now thinking about demolishing the old house and dividing the plot, as I don’t need the full 1000 sqm (10760 sq ft) and the proceeds from the sale would naturally benefit the budget for building a new house.

Now to my questions:
Does anyone have experience with demolishing prefabricated houses or houses from around 1970? Were many materials used at that time that are now considered hazardous waste? What are typical cost ranges for demolition?
The old house has a basement – could the excavation pit created by the demolition possibly be reused for the new construction?
Would a new or additional utility connection (e.g., water, electricity, sewage) be required due to the demolition and division of the plot, if another single-family house is built on the other half or if a semi-detached house is built together with the new owners?
Does the purchase price I pay for the entire plot including the existing building have to be disclosed to the buyer of the second half of the property, or is this publicly available somewhere?

Perhaps someone has already managed a similar project and can answer my questions.

I look forward to your responses.

Best of luck
Matze

Does the floor area ratio and the zoning plan allow for a larger building or subdivision of the property, or even a semi-detached house?

Yes, a subdivision is allowed according to the local authority, and this has already been done for a neighboring plot. Since this is an old district, there is no zoning plan. Construction must follow the style of the surrounding buildings. Nearby, there are already semi-detached houses and detached single-family homes, which we would use as a reference. I might still submit a building pre-application, if necessary. But now, please back to my questions.

Good, because before I take the time to answer your questions, it should at least be ensured that more than just the basic idea is in place.

1. Yes, a demolition company has experience. They can also provide you with cost estimates. Regarding asbestos, a specialist should inspect the house. They should be contactable through the demolition company, or the company may even offer this service themselves.
2. The basement must meet structural requirements – you should hire a structural engineer.

There may be experts in your area who can assess points 1 and 2 together.

3. Of course, when building behind an existing structure, utilities as well as the access road need to be extended to the new house. The waste (or debris) has to go somewhere. Providers usually include a standard length in their calculations.

4. No, why? Payment is based on market value. You can also get your price for a small gem.
However, I cannot help you with speculation.

Hello Matze

Removing an old basement and constructing a new one is a labor-intensive and costly undertaking. Why not use the existing basement, renovate it a bit, and build the new house on top of it? That would save a lot of money. Even in the 1970s, concrete work was sometimes done quite well.

Steven

Steven schrieb:

Removing the old basement and building a new one is a labor-intensive and costly undertaking. Why not use the existing basement, upgrade it a bit, and build the new house on top of it? That would save a lot of money. Even in the 1970s, concrete was sometimes done quite well.

In most cases, a simple "upgrade" is not enough; no contractor will build on an existing basement without a professional expert assessment and structural engineering evaluation. Besides, a new build would have to align with the existing staircase location, which might work but doesn’t necessarily have to.

Best regards, Bauexperte