Whether a rainwater tank requires a permit depends on its capacity, installation method, and local building regulations.

1. Above-ground tanks (freestanding)

✅ Do not require a building permit – if they are standard tanks with small capacity (e.g., up to 10 m³) and are not permanently attached to the ground.
⚠ May require notification – for larger tanks or when they affect the sewage system.

2. Underground tanks

✅ Tank up to 10 m³ – usually does not require a permit, but may require notification to the authorities.
⚠ Tanks above 10 m³ – may require a building permit, especially if they interfere with the ground on a larger scale.

3. When is a building permit required?

📌 When the tank has a capacity above 10 m³.
📌 If its installation involves expanding the rainwater drainage system.
📌 When the tank is part of a more extensive water installation on the property.

Summary

In most cases, a rainwater tank up to 10 m³ does not require a permit, but only notification to the appropriate authority. It is always worth checking local regulations, as they may vary depending on the municipality.

Do you have a specific location or type of tank in mind? 😊 We will answer each of these questions at tel.: (+48) 664 101 600