Foundation.

Every greenhouse starts in the ground

It is easy to think of a greenhouse as its glass and steel, but every structure ultimately stands or falls on what is beneath it. The foundation transfers all the loads the greenhouse will ever carry — its own weight, the crop hanging from the gutters, and the wind and snow pressing on the structure — safely into the ground, and it has to do so without settling unevenly, because a foundation that shifts distorts the whole frame above it.

A typical Dutch greenhouse foundation is efficient rather than massive. It consists of boreholes drilled at the column positions, a non-structural perimeter tie-beam that frames the footprint, all filled with concrete, and prefabricated steel foundation posts set precisely to receive the columns of the structure. Prefabrication matters here: because the posts are made to exact tolerances off site, the steel structure lands on a grid that is already true, which speeds erection and improves accuracy across the whole building.

Crucially, the foundation is scaled to the site rather than over-built as a matter of course. In most cases, and on reasonable ground, a lightweight foundation is entirely sufficient to carry a greenhouse, which is comparatively light for its footprint. Where the soil is poor — soft, made-up or high-water-table ground that cannot bear the loads directly — piling is applied instead, driving support down to competent strata. Matching the foundation type to the actual ground conditions avoids both the risk of under-building and the cost of needless over-engineering.

Which of those is required is not guessed at but calculated. Foundation design follows directly from the structural calculation and a proper assessment of the site: local wind and snow loads on the one hand, and a geotechnical picture of the soil on the other, together determine the depth, spacing and dimensions of the posts and beams. It is the least visible part of the greenhouse and one of the most important to get right. DutchGreenhouses® engineers the foundation from the structural loads and the site's soil data. Get in touch to discuss the groundwork for your project.