ᐅ Basement Construction – Costs for Shoring the Excavation in Cases of Boundary Adjacency?

Dear forum community,

We will be building soon (like many others here).
Our house will be constructed as a boundary wall build next to a garage that was supposedly founded deep enough for a neighboring structure. Unfortunately, no one from the construction company still remembers exactly how it was done – we will probably find out once the excavator starts work.

I am trying to get an idea of how high the costs could rise if it turns out that the garage has to be supported or shored up. Our adjacent house wall will be 10m (33 feet) long, and the garage is about 6.5m (21 feet) long plus a 2m (6.5 feet) path in front of it.

Thanks and best regards!
hptaccv

Hello,

hptaccv schrieb:

I’m trying to get an idea of how much the costs could increase if it turns out that the garage needs to be supported or secured? Our adjacent house wall will be 10 m (33 feet) long, the garage is about 6.5 m (21 feet) long plus a 2 m (6.5 feet) pathway in front….

Are you building on a concrete slab or with a basement?

Regards, Bauexperte

Hello,

hptaccv schrieb:


Our house will be built on a property line adjacent to a garage, which is supposedly founded deep enough for neighboring construction. Unfortunately, no one from the construction company remembers exactly how it was done – it will likely become clear once the excavator starts.

I’m trying to get an idea of how high the costs might rise if it turns out that the garage needs to be supported or shored up. Our adjoining exterior wall will be 10m (33 feet) long, the garage is about 6.5m (21 feet) long plus a 2m (7 feet) access path in front of it...

with basement!

I can’t think of any logical reason why the existing garage would be founded at basement depth, unless it actually has a basement.

Your house – specifically the basement slab – must be founded on undisturbed soil. This means you’ll need to excavate at least 3.00m (10 feet) deep, depending on the basement height clearances, plus clearance around for working space, based on the geotechnical engineer’s recommendations. If the garage is only a shallow structure, meaning it has no basement, it must be prevented from settling. These supports should ideally be integrated starting from your basement slab and extending upward.

For a house that requires underpinning, I would generally expect additional costs in the range of 8,000 to 9,000 euros (approximate). This includes earthworks. The garage is not as heavy as a house, but I would recommend budgeting around 1,000 to 1,500 euros (approximate) for this.

Best regards, Bauexperte