EPC label and rent indexation in Flanders: the correction factor explained

Last reviewed on 2026-06-10 · reading time ± 3 min

Between 1 October 2022 and 30 September 2023, Flanders froze rent indexation for energy-inefficient homes: with EPC label E or F (or without a valid EPC) you could not index, with label D only for half. That freeze is over, but it carries on permanently through a correction factor.

Who does the correction factor apply to?

To leases that entered into force before 1 October 2022 where the home has EPC label D, E or F (or no valid EPC). Contracts that started later, and homes with label A+, A, B or C, simply index according to the standard formula.

The formulas

For every indexation from 1 October 2023 onwards, you multiply the outcome of the standard formula by a correction factor:

• Label E or F (or no EPC): correction factor = index 2022 ÷ index 2023
• Label D: correction factor = (index 2022 ÷ index 2023) × (1 + 0.5 × (index 2023 ÷ index 2022 − 1))

"Index 2022" and "index 2023" always mean the health index of the month before your contract's anniversary in that year. The factor therefore differs per contract: a contract with a July anniversary uses the index figures of June 2022 and June 2023.

A worked example

Contract in force since 1 July 2021, basic rent € 800, EPC label F, indexation in 2025. Standard formula: 800 × index June 2025 ÷ index June 2021. Correction factor: index June 2022 ÷ index June 2023 = 121,02 ÷ 127,09 ≈ 0,9522. The indexed rent thus comes out more than 4% lower than without the correction factor — permanently, year after year.

How do you get rid of it?

The correction factor only lapses when you can present a new EPC with label A+, A, B or C (after renovation), or when an entirely new lease starts. Note: the Flemish coalition agreement announces that homes with label E or F would no longer be allowed to index at all from 2028 and could no longer be re-let from 2030 — renovating is becoming financially ever more important.

Calculate your indexation with correction factor

Our calculator automatically applies the right factor based on your EPC label and contract date, shows the full calculation and turns it into a legally correct letter.