A practical guide to understanding the issues and making the right decisions — before engaging your contractors.
Before talking technology, four fundamental questions must be answered. If you cannot answer them clearly, no contractor will be able to propose a suitable solution.
What is the occupancy profile? Hours? Heating, cooling and hot water needs? The presence of specific areas (server room, negative cold storage, production zone) changes the equation entirely.
The maximum power required and the duration for which it is needed determine sizing. An oversized system is inefficient. An undersized system fails to deliver on its promises.
RE2020 for new build, Tertiary Decree for renovation, CRREM for valuation, BREEAM or HQE if tenant requirements apply. Each constraint impacts eligible solutions.
What is the investment budget? What is the planned holding period? An owner selling in 5 years does not have the same rationale as a long-term investor. The optimal ROI changes entirely.
There is no universally superior solution. Each has its optimal application contexts.
| Solution | Investment | Operation | Constraints | Ideal context |
|---|---|---|---|---|
| Air-source heat pump | Low | Simple | Few | Standard renovation, constrained budget, limited performance |
| Borehole geothermal | High | Excellent | Ground, land | Long-term ownership, favourable ground |
| Aquifer geothermal | Medium | Excellent | Hydrogeology | Accessible aquifer, sufficient flow |
| Hybrid system | Moderate | Average | Adequate management | Investment/performance optimisation based on load profile |
An attractive subsidy does not justify an unsuitable solution. Operating costs over 20 years systematically exceed the subsidy benefit.
An overpowered system is inefficient at partial load. Engineering firms often oversize to avoid complaints — at the expense of your ROI.
The purchase cost of the system represents only 20 to 30% of the 20-year TCO. Energy, maintenance and replacements count for far more.
Signing a technical quote without understanding what you are signing. A decision-maker who does not understand the issues cannot ask the right questions — nor spot the flaws.
Not always. An independent third party brings most value in these situations:
An analysis tailored to your specific project — not a generic guide.