It's easier to retrofit than you think
Over 1,000 Danish homes have had rainwater harvesting systems installed after moving in. You decide the scope — from garden irrigation to full supply for toilets and washing machines.
Choose the scope based on your home and budget
You can start outdoors and expand later — as long as the tank is sized for it from the beginning.
Garden and outdoor use
Tank with pump for garden watering, car washing and outdoor taps. No modifications to the house's installations and no notification required for indoor use.
Toilet flush and washing machine
Underground tank, pump with top-up and a separate, marked rainwater circuit for toilets and washing machine. This is where the big savings lie.
Full integration
Combined with bathroom renovation, new flooring, or sewer separation, where the pipes are already exposed. Lowest additional cost per tap.
Check the prerequisites before proceeding
Fixed awning with downspout
Tiles, concrete, roofing felt, steel and eternit can all be used. We calculate with an effective collection area, not the full roof area.
Space in the garden
A buried tank requires access for an excavator and approximately 2 × 2 meters of clear space above the tank for the manhole cover and inspection.
Utility room or scullery
The pump, filter, and control unit must be kept frost-free with access to a drain and a dedicated electrical circuit.
No access to downspout
If all downpipes are located inside the structure with no access, setting up a collection system often becomes too expensive.
Very little roof area
Below approx. 60 m² effective roof area, the coverage becomes so low that the payback period becomes long.
From first glance to facility in operation
We advise, dimension, and supply. The excavation work and connection itself are carried out by authorized craftsmen — see the requirements under installation and authorization.
- 1. Non-binding review
We assess the roof, downpipes, garden, and technical room—either through pictures or a site visit—to determine what is possible.
- 2. Calculation and proposal
You will receive tank size, estimated coverage and savings, as well as a component list with prices including VAT.
- 3. Craftsmen on site
The sewer master excavates and installs the tank, the plumber connects the rainwater circuit, the electrician runs the circuit. You can use your own — or we can recommend some.
- 4. Startup and operations
We review, adjust, and test the system and train you in its daily operation. After that, you are responsible for the mandatory annual inspection.