Interreg Europe ABC · good practice

Underground Forest — carbon-storing wooden foundation piles

Underground Forest · NL

For centuries the Netherlands has carried its buildings on driven softwood piles. Below the groundwater table the wood never rots — the Palace on the Dam alone stands on 13,863 wooden poles, and roughly 25 million piles sit in Dutch soil, a dense "underground forest" that locks biogenic carbon away for centuries. Underground Forest (founded 2023, NL) revives and scales this technique deliberately for long-duration carbon storage: using wood instead of concrete for foundations both stores carbon and avoids cement emissions, pointing toward net-negative construction. Per cubic metre, solid timber stores an order of magnitude more carbon than bio-based insulation, and a foundation is a large, permanent volume of it.