EU Energy Performance Certificate (DPE) Renovation Auditor

Energy-inefficient homes: rental ban dates, works and grants

The tool rates the home from its primary energy use, recalls the French rental ban deadline (G since 1 January 2025, F in 2028, E in 2034) and estimates works, grants and payback. For 85 m² at 380 kWh/m²/year (class F) aiming for class C, it prices the works at €35,275, the net cost at €22,929 for a middle-income household and the payback at 5.2 years.

Calculations

• Class: from the consumption entered, using the official thresholds: A below 70, B from 70 to under 110, C 110 to under 180, D 180 to under 250, E 250 to under 330, F 330 to under 420, G from 420.
• Bill: consumption × floor area × price per kWh; the target is the middle of the chosen class (145.5 kWh/m² for C, the average of 111 and 180).
• Works: loft insulation €45/m², walls €90/m², heat pump €13,500, windows €7,500, ventilation €2,800.
• Grants: 70, 50, 35 or 15% of the total cost depending on income.
• Payback: net cost ÷ annual saving, without inflation. Green value = floor area × €3,200/m² × 10%.

Worked example

85 m², 380 kWh/m²/year, €0.22/kWh: a €7,106 bill against €2,721 in class C, i.e. €4,385 saved a year. The five items cost €35,275; a middle-income household receives €12,346 in estimated grants and pays €22,929, recovered in 5.2 years. Green value: €27,200.

Limits

The real French DPE keeps the worse of two ratings, energy and greenhouse gas; the tool only reads energy. Applying the price to primary energy overstates the bill of an electrically heated home. Grant rates are indicative, and the target class is assumed to be reached whatever items are ticked. For a quote you already have, use the energy renovation payback calculator. This is an estimate and does not replace an energy audit.

Sources and dates: French Act of 6 July 1989, article 6: a decent home must be rated F or better since 1 January 2025, E or better in 2028, D or better in 2034, timetable unchanged at 14/10/2026; order of 31 March 2021 on the DPE, thresholds in force since 1 July 2024; order of 13 August 2025: electricity conversion factor of 1.9 since 1 January 2026; Anah 2026 guide: MaPrimeRénov' at 80, 60, 45 or 10% of the pre-tax cost, within caps (checked on 14/10/2026).

Frequently Asked Questions

When will a class F home no longer be rentable in France?

In mainland France, from 1 January 2028: article 6 of the Act of 6 July 1989 then requires at least class E for a home to count as decent. Class G homes have not qualified since 1 January 2025, and class E homes will stop qualifying on 1 January 2034. This timetable was unchanged as of 14 October 2026.

From what consumption is a home rated G?

A home is rated G from 420 kWh of primary energy per m² per year, or from 100 kg of CO2 per m² per year: the worse of the two ratings applies. The tool only reads energy consumption.

Has my electrically heated home's DPE changed in 2026?

Possibly: since 1 January 2026 the factor for converting electricity into primary energy has dropped from 2.3 to 1.9 (order of 13 August 2025), and it will fall to 1.7 on 1 January 2027. An electrically heated home therefore shows lower consumption, sometimes one class better. Enter the figure from your most recent DPE in the tool.

How much do works cost to upgrade an energy-inefficient home?

Using the tool's unit prices, insulating the loft and walls of 85 m², installing a heat pump, replacing the windows and fitting ventilation comes to €35,275. In 2026, MaPrimeRénov' for major renovations covers 10 to 80% of the pre-tax cost depending on income, within a spending cap of €30,000 or €40,000 excl. VAT, provided the home gains at least two classes.

Is this tool really free?

Yes, all tools on Kristools are 100% free and accessible without registration.

Is my data protected?

Yes. All processing is performed directly and securely inside your browser. No personal data is sent to our servers.