Property value: how much does geothermal add when you sell your house?

Investing in a 150-metre geothermal borehole with WellDoneDrill means a bigger initial budget than a conventional boiler or an air-source heat pump. However, it is one of the few renovations whose return on investment (ROI) is immediately visible in the market value of the property. In 2026, geothermal has become the "gold standard" of prestige, high-performance real estate. Here is why.

1. The "energy guzzler" effect: the market's new dividing line

The Belgian property market is now split in two: energy-efficient homes (rated A and B) and "energy guzzlers" (rated D, E, F, G).

• The discount: A house heated by gas or oil now suffers a "green discount". Buyers systematically deduct the cost of future energy renovation work from the sale price.
• The premium: Conversely, a house fitted with geothermal probes benefits from a "green value". On average it sells for 10 % to 15 % more than an equivalent property without, because it gives the buyer financial peace of mind for the next 30 years.

2. An "invisible" but indestructible asset

Unlike a fitted kitchen or a trendy bathroom that looks dated after 10 years, a geothermal borehole is a structural asset.

• In a property valuation, HDPE probes at 150 metres count as a lasting improvement to the land, just like reinforced foundations or high-end roof insulation.
• Since the probes last more than 50 years, their value barely depreciates. Even 20 years after drilling, the underground infrastructure keeps 100 % of its usefulness and value.

3. The "four-season comfort" argument (geocooling)

Cooling has become an essential luxury criterion. Buyers dread houses that turn into "greenhouses" in Belgium's increasingly hot summers.

• A house that stays at 22 °C inside when it is 35 °C outside, at a negligible running cost thanks to geocooling, is a knockout selling point.
• It is a far more attractive alternative to noisy air-conditioning units on the walls, which are often seen as an eyesore.

4. No more energy uncertainty for the buyer

The 2026 buyer is anxious about energy prices. By showing them a WellDoneDrill installation combined with a few solar panels, you are selling them a controlled budget.

• A house whose heating and cooling bill is divided by four reassures banks when granting a mortgage (higher repayment capacity).
• That direct financial comfort translates into the buyer's ability to raise their offer to buy your property rather than another.

5. A WellDoneDrill installation: a mark of trust

The quality of the drilling and of the geothermal grout seal is crucial. By providing WellDoneDrill's complete technical file (geological log, drilling report, probe data sheets), you prove the quality of the work. That transparency removes the buyer's doubts and speeds up the signing of the sale agreement.

Conclusion

Geothermal is not a comfort expense; it is capitalisation. Every euro invested in your vertical borehole is "stored" in your property. By choosing WellDoneDrill, you are not just heating your home; you are building a financial asset that will make your property unique and highly desirable in tomorrow's market.