Water Storage & Paving Rules: How Much Can You Pave Over?

Yes, but it rarely affects ordinary private gardens. The Hoogheemraadschap van Rijnland applies this rule under its "Keur" (water bylaw), Policy Rule 4 on compensating hard surface:

• Less than 500 m² increase in hard surface (paving, buildings, etc.): exempt from the compensation requirement. Note: successive smaller projects that together exceed 500 m² do count.
• 500 m² or more: you must compensate 15% of that new hard surface with extra water storage (preferably open water), and you need a water permit from Rijnland for this.

For an ordinary back garden, 500 m² of new paving in one go is, in practice, very large - this mainly applies to large plots, commercial sites or major new-build developments, not an average patio or driveway.

That is climate advice, not a legal requirement. Organisations such as Milieu Centraal and local greening initiatives recommend paving no more than 40 to 50% of a garden, so rainwater can soak into the ground instead of running off to the sewer, and the garden doesn't heat up further in hot weather. Sensible to follow, but there is no permit requirement or penalty for exceeding it - unlike Rijnland's 500 m² rule above.

Yes: the municipality runs the "Elke tegel telt" ("every tile counts") awareness campaign and organised the Haarlemmermeer tile-lifting championship, in which participants removed 30,000 kg of paving slabs from their gardens in the first round. This is voluntary, with no mandatory target percentage. Haarlem and Amstelveen also take part in the national NK Tegelwippen, with a free collection service for removed tiles. Want to swap paving for a permeable alternative yourself? A gravel garden is often a practical middle ground between full paving and full planting.