Applicable rules for rainwater in Denmark
All our systems are VA-approved and meet the requirements of the Danish Building Regulations and DS/EN 16941-1. Here are the rules that you and your contractors need to be aware of.
It must be in place in every facility
Wastewater approval
All components touching the rainwater installation must be VA-approved so that they cannot be mistaken for or connected to the drinking water installation. We only use approved components, and the approvals are included with the documentation.
Permitted use
Rainwater may be used for toilet flushing, machine washing clothes, and outdoor purposes such as garden watering and car washing. It must never be connected to drinking water taps, baths, kitchen sinks, or dishwashers.
Backflow preventer
Re-filling with potable water may only take place through an approved backflow prevention device with a free air gap, typically category 5. A direct connection between rainwater and potable water is illegal regardless of the valve type.
Labeling
Pipes, taps and tank lids must be clearly marked to indicate that the water is rainwater and not drinking water. Outdoor taps must also be secured against unintended use.
The Danish Building Regulations (BR18)
The facility must comply with BR18's requirements for drainage, water installations, and operation. The work must be carried out by authorized companies in sewerage, plumbing, and electrical work.
Complaint to the municipality
Establishment must be reported to the municipality, which also sets requirements for overflows and any drainage. We provide the documentation your sewer master and plumber must submit.
Standards and Orders
The rules are spread across several sets of regulations. Here are the four that are most frequently in play when a rainwater harvesting system needs to be approved and documented.
- DS/EN 16941-1
European standard for non-potable water systems – design, installation and operation of rainwater harvesting systems.
- BR18, Chapter 21
Requirements for water and drainage installations, including protection against contamination of drinking water.
- The Authorisation Act
Sewerage, plumbing, and electrical work may only be carried out by authorized companies within each respective field.
- Wastewater Order
Regulates drainage and overflow from the tank to the sewer, soakaway, or SUDS solution.
About regulations and approvals
Do I need to apply for a permit if the system is only used in the garden?
An installation that exclusively supplies outdoor taps and is not connected to the house's installations usually does not require notification. However, if there is an overflow to the sewer or a soakaway, this must be agreed upon with the municipality.
Is the annual inspection mandatory by law?
Yes. Facilities for toilet flushing and laundry must have an annual inspection with a corresponding service report, so that filters, fuses, and labeling are documented as being in order. This can be covered by a service agreement.
May I install the system myself?
No. Sewer connections, water installations, and electrical connections require authorization. You are welcome to handle excavation and preparations, but the connections must be performed and documented by authorized professionals.
Can rainwater be used in commercial and office buildings?
Yes, and the potential is greater because toilet flushing and cleaning account for the majority of consumption. The same rules regarding VA approval, labelling, and security apply.
The guidelines here are general. Municipalities may impose supplementary requirements for overflow or drainage, so the final set of rules should always be clarified with your municipality and your authorised craftsmen.