ᐅ Demolition of Property and New Construction at a Different Location – Soil Contaminated with PFCs

Hello everyone,

We have been searching for a house or land for quite some time and have now found a suitable plot. It is a corner lot of just under 700 sqm (7,535 sq ft). On the property there is an existing building from around 1950 with about 100 sqm (1,076 sq ft) of living space and a double garage; the building has no basement. The house has severe moisture damage, so our preferred option would be demolition.

Since the house currently sits in the southern part of the lot, we would like to demolish it and build the new house in the northern section. However, there is a special condition with this site. The soil has been contaminated with PFCs. The lot was remediated in 2018, and since then, any excavated soil must be disposed of as hazardous waste.

Is it possible, after demolishing the existing building, to refill the open area with the excavation soil from the new construction? This would avoid disposal costs. The local building authority at least has approved this approach, as the excavated soil would not leave the property.

But is this also feasible in practice? In your opinion, what else should be taken into account when relocating the building site in this way? Currently, electricity and telephone connections are overhead on a pole, and these will be switched to underground cables.

Thank you very much in advance and best regards

Contaminated sites... a sensitive topic!

Before you proceed, I would recommend obtaining a written approval for reuse from the relevant authority, which is usually the environmental agency if one exists in the municipality. I could imagine there being an issue with the groundwater.

All excavation material must definitely be tested in such cases and then disposed of properly. You will face the same issue when landscaping the garden.

This requires a lot of patience and, above all, a deep wallet. Costs can quickly reach six figures.

I would avoid that. Especially the issue with the groundwater can hang over you for a long time. In the worst case, years later an authority might require a complete replacement of the soil if they find that it is seeping into the groundwater.

sysrun80 schrieb:

I would advise against it. Especially the issue with the groundwater could hover over you for a long time. In the worst case, an authority might demand a complete soil replacement after a few years if they find that contaminants are seeping into the groundwater.

This concerns an entire area that is contaminated. The pollution has already reached the groundwater. That is why there is a restriction prohibiting the use of groundwater for irrigation.
In principle, no further actions from the authorities are expected. This issue has actually been known for over five years.

louis.wois schrieb:

What else do you think should be considered when relocating the building site like this?

Does the building envelope / construction boundary allow for this?
Basically, the same rules apply as with a new build: floor area ratio, setback distances, building envelope / construction boundary, building permit / planning permission, and so on.