EPC renovation: concrete impact on renting your property
Renovating to improve your rental property's EPC: impact on rent, indexation, deposit and yield. Figures and analysis by region.
Concrete impact of the EPC on rent
The EPC has become the second most important criterion for Belgian tenants in 2026, after price. A better energy score allows a higher rent to be charged while attracting better profiles.
| EPC class | Average rent 2 bed. (Brussels) | Difference vs EPC D |
|---|---|---|
| A-B | 1,020 EUR | +15% |
| C | 950 EUR | +7% |
| D | 890 EUR | Reference |
| E | 810 EUR | -9% |
| F-G | 750 EUR | -16% |
A landlord who renovates from EPC F to EPC C can increase their rent by 200 EUR/month in Brussels. Over a year, that is 2,400 EUR in additional income. Combined with the tenant’s charge savings, the renovated property is more attractive in every respect.
EPC renovation increases the rent AND reduces the tenant’s charges. This is a unique selling point: the tenant pays more rent but less in total (rent + charges).
EPC and the right to indexation
The EPC-indexation link varies by region and is a major financial issue:
| Region | EPC F-G | EPC E | EPC D or better |
|---|---|---|---|
| Brussels | Indexation banned | 50% of the index | 100% |
| Wallonia | EPC required (no minimum score) | 100% | 100% |
| Flanders | No restriction | 100% | 100% |
In Brussels, a landlord with an EPC F property at 850 EUR rent loses approximately 400-500 EUR per year in blocked indexation. Over 5 years, that is 2,000 to 2,500 EUR of lost income — often more than the cost of roof insulation.
The impact of inflation on rents shows that indexation is the primary driver of rental income growth.
EPC and rental deposit in Brussels
Since July 2026, the Brussels lease reform also links the rental deposit to the EPC:
| EPC class | Maximum deposit |
|---|---|
| A-D | 3 months’ rent |
| E-G | 2 months’ rent |
For a rent of 900 EUR, that is 900 EUR less in deposit. This is not a direct cost for the landlord but reduced protection in the event of damage or unpaid rent.
Which works to prioritise
Not all works have the same impact on the EPC score. Here is the ranking by cost/gain ratio:
| Works | Average cost | Average EPC gain | Wallonia grant | Payback |
|---|---|---|---|---|
| Roof insulation | 5,000 - 12,000 EUR | 1 to 2 classes | 4,000 - 6,000 EUR | 2-4 years |
| Boiler replacement (heat pump) | 8,000 - 15,000 EUR | 1 to 2 classes | 6,000 - 10,000 EUR | 3-5 years |
| Wall insulation | 10,000 - 25,000 EUR | 1 class | 5,000 - 8,000 EUR | 5-8 years |
| Double glazing windows | 5,000 - 15,000 EUR | 0.5 to 1 class | 3,000 - 5,000 EUR | 5-7 years |
| Mechanical ventilation | 3,000 - 6,000 EUR | 0.5 class | 1,500 - 3,000 EUR | 4-6 years |
Roof insulation is the first investment to make: best cost/EPC gain ratio and fastest payback. The renovation grants cover 30 to 50% of costs.
Roof insulation + boiler replacement = improvement of 1 to 2 EPC classes in a single intervention. This is the most effective combination for a budget of 15,000 to 25,000 EUR.
Profitability calculation: concrete example
Scenario: 2-bedroom flat in Brussels, EPC F, rent 780 EUR
| Item | Before renovation | After renovation (EPC C) |
|---|---|---|
| Monthly rent | 780 EUR | 900 EUR (+15%) |
| Annual indexation | Blocked | +2% (~216 EUR/year) |
| Maximum deposit | 2 months (1,560 EUR) | 3 months (2,700 EUR) |
| Tenant charges | ~280 EUR/month | ~160 EUR/month |
Investment: 18,000 EUR (roof insulation + heat pump) Grants: -10,000 EUR (Renolution Brussels) Net cost: 8,000 EUR Annual gain: +1,440 EUR (rent) + ~400 EUR (indexation) = 1,840 EUR/year Return on investment: 4.3 years
This is one of the best possible investments for a landlord. Calculate your own scenario with our rental yield method and explore the energy performance standards by region.
Frequently asked questions
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Yes. Immoweb studies show that an EPC B property rents for an average of 10 to 15% more than an equivalent EPC E property in the same municipality. This is the most direct return on energy renovation.
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In Brussels: yes. EPC F-G properties cannot index. Moving to EPC E unlocks 50% of indexation, EPC D or better unlocks 100%. In Wallonia: the EPC is required for indexation but there is no minimum score.
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On average 3 to 7 years depending on the works and the region. Roof insulation (best cost/gain ratio) pays for itself in 2 to 4 years via the rent increase and charge savings. Regional grants accelerate the return.
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