Gravel foundation for garden house/tool shed

Gravel with concrete slabs - that's roughly what our landscape gardener also advised us. Absolutely fine for small houses - especially since it would be strange if the foundation ends up costing more than the house.

Gravel costs €10 per cubic meter including delivery. We are talking about €50-70 for the garden house soil replacement. Of course, it can be done with less.

To be honest – hello, it’s a garden shed.

I can agree with you there
Our old garden shed (at the old house), back then of course new, had concrete slabs 50x50 as foundation. On solid ground, formerly lawn.
Nothing more! No gravel, nothing dug out. You’re not allowed to mention that in a forum
The shed was a common one from the hardware store, back then around €500 for 2.20 x 2.50 with floor panels. We paid more attention to the roof: good thick foil and welded, instead of the supplied one.
It’s probably still rock solid

What I want to say: everything will be fine!

My landscape gardener quickly dug the pit with the excavator, it must have been about 30cm. Gravel in, compacted, and gravel screed on top, then paving. More than enough for our house. My parents-in-law had dug out about 25cm for gravel and 6cm of paving, and the house still stands strong. Depending on the weight and possible wind exposure, I would consider a point/strip foundation and anchoring in it, which was not necessary for us due to the weight and the sheltered location.

The costs for gravel vary both regionally and from company to company, as with many things. Here with us, the gravel including delivery would cost about €100. Then there is the question of where to put the excavated soil. If there are no holes to fill on your own property or you know someone who will take it, the only option is to have a container delivered and then dispose of it. Here locally, a 3 m³ container costs about €200 according to the internet, and for a 7 m³ one, you have to pay about €300.

This ultimately means that, depending on the type of house, the ground of the house can be more expensive than the house itself.

You should, if possible, keep things reasonable and not build something more elaborate than necessary.

we also only laid the cheapest (but strongest) terrace slabs and then made the wooden substructure... No compaction blah blah