Heat pumps — your most comfortable step toward lower energy costs

How does a heat pump work — the short version

A heat pump is essentially a reversed fridge. A fridge removes heat from inside and dumps it into the room; a heat pump extracts heat from outside air, the ground or groundwater, and pumps it into your home. Thanks to a thermodynamic cycle (evaporation, compression, condensation, expansion), the pump delivers several kilowatt-hours of heat per kilowatt-hour of electricity it consumes.

This ratio is called the COP (Coefficient of Performance) at a given moment and the SCOP (Seasonal COP) across an entire heating season. A modern air/water heat pump has a SCOP of 3.8-4.5 — every kWh of electricity it uses delivers 3.8-4.5 kWh of heat. A geothermal pump easily reaches 4.5-5.5.

The 4 decisive factors for your efficiency

• Emitter temperature — the lower the water circulating in your underfloor heating or radiators, the higher the COP. 35 °C underfloor is ideal; 55 °C old radiators works too but COP drops to 2.5-3.0.
• Insulation — in a poorly insulated home the heat pump has to work harder to compensate for losses. Below EPC label E/F this quickly becomes too expensive to be profitable without insulating first.
• Outside temperature — every degree of cold weakens the COP. Modern inverter-driven pumps compensate, but at -10 °C realistically expect a COP of 2.0-2.5.
• Unit sizing — an undersized pump runs at 100% constantly in cold weather; an oversized pump cycles on/off continuously, shortening its lifespan. Proper sizing is critical — our engineering calc accounts for your home heat-loss calculation (EN 12831).

Which heat pump fits your home?

This is our 2-of-3 rule at the on-site visit: a full heat pump works well if at least two of these three conditions are met: (1) your home has EPC label D or better, (2) your emitter system can run at 45 °C or below (underfloor heating, or oversized radiators with > 0.6 kW/m² output), (3) you have solar panels to cover the electricity consumption. If only one is met, a hybrid solution is usually smarter — you keep the gas boiler for peak cold and let the heat pump run most of the year.

Compared head-to-head: air/water, hybrid or geothermal

Technology-agnostic advice. We pick what fits, not what earns commission.

Prices include VAT (6% for homes older than 10 years through 2029). Subsidies per Mijn VerbouwPremie 2026, category 4. Figures are realistic market estimates for the Brussels/Mechelen/Leuven area; your actual quote may vary based on capacity, complexity and labour rate.

From site visit to commissioning — our 5 steps

Subsidies and VAT in 2026 — what do you actually get?

Federal VAT rules and regional subsidies changed substantially in 2025-2026. Here is the realistic table we use for a Brussels/Flemish renovation in 2026:

VAT rate

• 6% VAT for homes older than 10 years, through 2029 — remains in place for heat pumps, hybrids and geothermal systems.
• 6% VAT also for new-builds since 01/01/2026, for 5 years — a significant change.
• 21% VAT applies to gas boilers in homes 10+ years old since 01/07/2025, and to nearly all oil-boiler replacements. The heat-pump component of a hybrid stays at 6% VAT.

Mijn VerbouwPremie (Flanders) — heat pump

The subsidy amount depends on your income category and heat-pump type:

• Cat. 4 (modest income): up to €8,000 (geothermal) / €6,000 (air/water) / €4,000 (hybrid)
• Cat. 3: up to €6,000 / €4,500 / €3,000
• Cat. 2: up to €3,000 / €2,250 / €1,500 (halved vs. 2025)
• Cat. 1 (high income): REMOVED since 01/03/2026 — no longer possible to act after that date if you had not yet started.

Income thresholds 2026: Cat. 4 single ≤ €24,750 / household ≤ €35,300. Cat. 3 up to €43,240 / €61,680. Cat. 2 up to €55,020 / €78,500. +€4,420 per dependent.

Brussels (Prime Renolution / Homegrade)

Brussels addresses benefit from Prime Renolution with amounts between €1,800 and €7,500 for heat-pump installations, depending on income and home type. Specific application via Bruxelles Environnement; we help you assemble the full file.

Wallonia (Primes Habitation)

For clients in Walloon municipalities (e.g. Brabant Wallon borders): Primes Habitation offers similar support, with since January 2026 a replacement ban on oil boilers when they fail — a heat pump or gas boiler becomes the legal successor. Specific amounts: up to €6,000 depending on income.

Combinability

Mijn VerbouwPremie + EPC Label premium (until 01/07/2026, up to €2,500 extra) + reduced VAT (6%) + tax deduction for energy-saving expenses: all combinable. Our subsidy calculator does the math for you and gives a realistic net cost in 2 minutes.

Heat pump FAQs

The 12 questions we get most often on site visits. Have a different question? Send us a message or call 015 62 70 80.