The Social Leap of Water

Key results

Key lessons learned

1. We developed a water recovery strategy applicable to the renovation of ground-based social housing units. We focused on feasible design and integration into existing systems. The desire for residents not to have to move during the works posed a challenge.
2. Based on our strategy, we developed a detailed design for a specific project, which was then implemented: the installation of rainwater and greywater recovery systems during the renovation of four old social housing units in Hoeselt.
3. During the project execution, some unforeseen constraints arose. The actual costs incurred were analyzed and, if possible, made future-proof to avoid them in case of scaling up.
4. We began the evaluation of the model on a larger scale. We observed that collective systems have a financial advantage over individual ones. However, on a large scale, underground installations become complex, making them difficult to reproduce.

1. Installing water recovery systems during the renovation of existing homes is not easy due to the (often undocumented) spaghetti of existing pipes. Thorough preparation is crucial, and even then, surprises are possible.
2. It only makes sense to recover water for lower-grade reuse such as for toilets, washing machines, the garden... Converting it into drinking water is too expensive and too complex.
3. It's regrettable how energy renovations of social housing receive attention, but little thought is given to other sources that could be managed more efficiently, such as water. In one of our pilot project homes, for example, an IBA system fit in the space of a removed oil tank.
4. The financial savings on the water bill are not sufficient for a viable business case. Only by working on a larger scale or offering additional services is there a chance of success. The benefits also lie in difficult-to-quantify gains such as reduced CO2 emissions, circular water reuse, etc.