Foundation for a canopy or garden house: footings or screw piles

Updated 26 October 2026 · 5 min read

For a canopy or garden house you usually choose between concrete footings (betonpoeren), screw piles, or a tile or strip foundation. What fits depends on the weight of the structure, the soil and whether you want to be able to remove the foundation later. Just as important: the whole structure must not lift in the wind or settle.

What must a foundation withstand?

A foundation does more than carry the weight of the structure. It also has to:

• carry snow and self-weight into the ground (the characteristic snow load in the Netherlands is about 0.7 kN/m²);
• resist wind, both sideways and upward. On an open canopy with a light roof, wind acts as suction that tries to pull the roof up;
• cope with frost, so the structure does not shift or tilt.

Wind load depends on where in the Netherlands you live and how open your surroundings are. If you want to know exactly, you need a calculation.

The three common options

Concrete footings

You dig a hole, add reinforcement if needed and pour concrete. A post base or anchor plate goes in, and the timber post is mounted on it. The post then does not stand in the soil, which helps prevent rot.

• Strong and reliable for posts with high compression and uplift forces.
• Needs digging, concrete and curing time.
• Hard to remove if you later move or renovate.

Screw piles

Steel piles that are screwed into the ground. They are installed quickly, need no concrete and can in principle be removed again.

• Fast and clean, handy in a small garden or hard-to-reach spot.
• You need equipment or a contractor to drive them.
• Suitable for many soil types, but stones or rubble in the ground can make it difficult. A trial placement gives certainty.

Tiles or strip foundation

For a lighter garden house or small structure, a tile or concrete strip foundation can be enough. A paving bed of load-bearing sand, possibly with a concrete strip, serves as the base.

• Simple and often the cheapest for light, small structures.
• Less suitable when there are significant uplift or settlement forces.
• For a garden house with a floor or heavy build-up the details matter, and they differ per design.

Comparison at a glance

How deep?

As a rule of thumb, frost-free depth for foundations that must not heave in the Netherlands is usually taken as 0.6 to 0.8 metres. This applies mainly to structures that must not lift or settle. For a light garden house on a flexible base a shallower solution may do, but the design must be able to cope with that. If in doubt, ask a structural engineer or an experienced contractor.

Anchoring against uplift

A canopy has little weight and a large roof area, so wind acts more like lift than pressure. Keep these points in mind:

• A post foundation must hold the post in place, not just carry it. Use a galvanised post base or anchor plate with the right bolts.
• Use plates or brackets between post, beam and purlin where needed, so forces travel through the entire structure.
• Do not simply place loose slabs under an open canopy; it can blow away.
• A polycarbonate roof sheet is light and catches a lot of wind. See polycarbonate or glass.

Note: a Hofplan drawing is not a structural calculation. If a permit is needed, it comes with a calculation by a structural engineer (constructeur), including the foundation.

Near the property boundary

If you build close to the boundary, remember that digging can affect your neighbour's garden or pipes. Talk about it; see neighbours and boundaries. Always have cables and pipes checked before you dig (a KLIC notification via the Kadaster).

What next?

Design your structure in the free configurator and see how many posts and what loads you need. What a foundation costs is in cost of building yourself, and what belongs on a good drawing is in what a canopy drawing contains.

Try it yourself