Most homeowners want to know what they are actually investing and what they can expect to save. Here, you'll get an honest overview of prices, savings, and payback periods.
Finances are a natural part of the decision-making process when considering a rainwater harvesting system. It's an investment in your home, and it's perfectly reasonable to want to understand the numbers before taking the next step. Here, we give you a realistic picture of what a system costs, what you save, and when the investment pays for itself.
What does the system itself cost?
The price of a complete rainwater harvesting system for a typical household depends on the size of the home, the roof area, and the chosen equipment. As a rule of thumb, you can expect the following price ranges:
The basic package typically includes an underground tank (3,000–5,000 liters), a pre-filter, a pump with automatic switchover to drinking water, and the necessary pipes and fittings. For the products alone, the price typically ranges from 25,000–45,000 Danish kroner, depending on tank size and component quality.
Installation comes on top and varies with local conditions. Excavation, connection to gutters and downspouts, and the establishment of a separate pipe network inside the home are the primary expenses.
In new construction, installation is simpler and cheaper, as the pipes can be laid from the start. For existing homes, it requires adaptation, and the price depends on the building's structure and access conditions. A total installation price of 15,000–35,000 Danish kroner is a realistic range for most projects.
The total investment for a complete, installed system thus typically falls within the range of 40,000–80,000 Danish kroner for an average household.
It is important to emphasize that prices vary — and that it is always a good idea to get a specific quote based on your particular home.
How much do you save on your water bill?
A rainwater harvesting system can replace up to 50 percent of your drinking water consumption, because toilet flushing, laundry, and garden watering together account for a large portion of a household's total water consumption.
Let's look at a specific example. A typical Danish household with four people uses about 140 cubic meters of water per year. If the rainwater harvesting system replaces half, you save approximately 70 cubic meters of drinking water annually.
The total price for water and drainage varies from municipality to municipality, but typically ranges between 50 and 80 Danish kroner per cubic meter. This results in an annual saving on drinking water in the order of 3,500–5,600 Danish kroner.
In addition, many municipalities charge a separate rainwater drainage fee. If you disconnect parts of your rainwater from the sewer — because it is instead collected and reused — you may, in some municipalities, achieve a reduction in this fee. This varies from municipality to municipality, so it's worth researching the rules in your specific municipality.
When does the investment pay for itself?
The payback period depends on three factors: the total investment, the annual water savings, and any savings on rainwater drainage fees.
With a conservative calculation — an investment of 60,000 Danish kroner and an annual saving of 4,000–5,000 Danish kroner — the system pays for itself in 12–15 years. If you include savings on the drainage fee, the payback period can decrease to 8–12 years.
This may sound like a long time, but it's important to put it into perspective. A rainwater harvesting system with quality components has an expected lifespan of 25–30 years or more. This means that after the payback period, you have many years of pure savings. At the same time, water prices in Denmark are continuously rising — a development that makes the savings greater with each passing year.
The hidden savings
In addition to direct water savings, there are some benefits that do not always appear in the calculation but are worth mentioning:
Less limescale in the washing machine. Rainwater is soft water and contains almost no limescale. This extends the life of the washing machine and reduces the consumption of detergent and descaling agents.
Less strain on the sewage system. By collecting rainwater, you reduce the amount of water sent directly into the sewer during cloudbursts. This is an advantage for both the sewer network and the environment — and a point that several municipalities are beginning to recognize in their fee structure.
Value for the home. A well-functioning rainwater harvesting system is an improvement to your property that can be attractive to future buyers — especially as sustainability and water savings gain increasing attention.
An investment in security — and common sense
A rainwater harvesting system is not a quick win — it is a long-term investment in your home and your water consumption. Like insulation or new windows, it is an improvement that pays for itself over time, reduces your fixed expenses, and makes your home more robust.
The most important thing is to choose quality components from proven manufacturers and ensure correct installation. Then you'll have a system that takes care of itself for years and saves you money while doing good for water resources.
Are you ready to find out what a rainwater harvesting system would cost for your home? Contact us for a no-obligation chat — we'll help you find the right solution.
0 comments