How to improve your DPE rating in France

The DPE (Diagnostic de Performance Energétique) is France's energy performance certificate for residential properties. It rates buildings from A (excellent) to G (very poor) based on estimated primary energy consumption and greenhouse gas emissions. For property owners on the Côte d'Azur, two deadlines have made the DPE politically urgent: G-rated properties have been banned from new rental contracts since January 2025, and F-rated properties follow in January 2028. If you own a villa or apartment that sits below D on the DPE scale, improving the rating is no longer optional, it's a financial and legal imperative.

This guide explains how the DPE score is calculated, which improvement measures have the biggest impact on properties in the south of France, and how to prioritise your renovation spend.

Mediterranean villa on the Côte d'Azur typical of properties affected by DPE rental ban rules

How is the DPE score calculated?

The DPE is calculated using a standard methodology (the 3CL method) that models the property's energy consumption from fixed inputs: floor area, construction type, wall and roof insulation levels, glazing, heating system, hot water system, and ventilation. It uses reference climate data for each of France's eight climate zones rather than your actual consumption bills.

PACA sits in climate zone H3 (Mediterranean), which affects the reference heating and cooling loads used in the calculation. Because the H3 reference climate has mild winters, the heating load is lower than in northern France. This means the heating system has less impact on the DPE score in PACA than it would in Brittany or the Île-de-France, and other factors such as the quality of the building envelope (walls, roof, windows) often matter more.

The DPE letter is determined by the worse of two sub-scores: primary energy consumption in kWh/m²/year, and greenhouse gas emissions in kg CO2eq/m²/year. A property heated by oil or gas can score poorly on the emissions sub-score even if its energy consumption figure is acceptable. This matters when deciding which measures to prioritise.

What are the DPE letter thresholds?

A: less than 70 kWh/m²/year primary energy
B: 70-110 kWh/m²/year
C: 110-180 kWh/m²/year
D: 180-250 kWh/m²/year
E: 250-330 kWh/m²/year
F: 330-420 kWh/m²/year
G: more than 420 kWh/m²/year

Moving from F to C typically requires reducing the modelled consumption by 150-250 kWh/m²/year. For a 100m² property, that's 15,000-25,000 kWh of modelled savings. No single measure achieves this on its own in most properties, which is why the MaPrimeRénov' parcours accompagné scheme (which covers global renovation projects across multiple measures) offers higher subsidy rates than single-measure grants.

Which measures have the biggest DPE impact?

The impact of any measure depends on the starting state of the property. That said, for the typical older Riviera villa or apartment that currently sits at E, F, or G, the following hierarchy applies in most cases:

1. Roof and loft insulation

Roof insulation typically delivers the largest single DPE improvement of any measure, because heat loss through an uninsulated roof accounts for 25-30% of the total in the DPE model. If the property has an accessible loft space and no existing insulation (common in older Provençal construction), adding 200-300mm of mineral wool or blown-in insulation can move the DPE score by 1-2 letter classes on its own. The cost is relatively low compared to other measures: 1,500-4,000 EUR for a 100m² property depending on access difficulty. It is also eligible for MaPrimeRénov' and CEE subsidies.

2. Replacing the heating system

If the property is heated by an old electric resistive system, oil boiler, or gas boiler, switching to a heat pump makes a significant difference to both energy consumption and the emissions sub-score. An air-to-water heat pump with a SCOP of 4.0 delivers the same heat for 75% less electricity than resistive heating. For properties on oil or gas, the emissions sub-score improves substantially because electricity in France has a lower carbon intensity than fossil fuels in the DPE calculation.

The DPE impact of a heating system change alone is typically 1-2 letter classes for a property switching from oil or gas to a heat pump. Reversible heat pumps (air-to-air systems) improve the energy score but have less impact on the emissions sub-score than air-to-water systems connected to a wet heating circuit, because the DPE methodology applies a higher primary energy coefficient to electricity used for air-based systems. For the best DPE outcome, air-to-water is usually the right choice.

3. Wall insulation

External wall insulation (isolation thermique par l'extérieur, or ITE) is the most effective approach where it's possible, but on many Riviera properties it is either prohibited in ABF protected zones or unwanted because it changes the character of the facade. Internal wall insulation (isolation thermique par l'intérieur, or ITI) sacrifices a small amount of floor space but is typically permitted. The DPE impact is meaningful, particularly for single-skin stone construction which is common in older village houses and rural properties in departments 06 and 83.

4. Window replacement

Upgrading from single glazing to double glazing improves the DPE score, but the gain per euro spent is lower than roof insulation or heating system replacement. It's typically the third or fourth priority unless the existing windows are very old. Properties already fitted with modern double or triple glazing gain little from upgrading further.

5. Hot water production

If the property uses an old electric tank water heater (chauffe-eau électrique with a resistive element), switching to a thermodynamic water heater (chauffe-eau thermodynamique) or to solar thermal significantly reduces the hot water component of the DPE score. Thermodynamic water heaters work like a heat pump for domestic hot water and use 2-3 times less electricity than a resistive tank for the same volume of hot water. This measure is lower-impact than roof insulation or heating system replacement but can contribute usefully as part of a combined renovation programme.

Does solar PV improve the DPE?

The short answer is: it helps, but less than most people expect. The 3CL DPE methodology does account for on-site electricity generation from solar panels, which reduces the calculated primary energy consumption. However, the gain is capped at the self-consumption portion, not the total production, and the calculation methodology discounts the value of surplus exported. For most properties, solar panels alone will not move the DPE by a letter class. They're valuable for reducing energy bills but should not be the primary strategy for improving the DPE rating.

What is a global renovation and why does it matter for subsidies?

MaPrimeRénov' offers two funding routes. The par geste route covers individual measures (insulation, heat pump, etc.) and is available without a prior audit. The parcours accompagné route covers global renovation projects that improve the DPE by at least two letter classes, requires a prior audit énergétique, and offers higher subsidy rates, particularly for lower-income households.

For owners of F or G-rated properties who need to reach D or better before the 2028 deadline, the parcours accompagné is often the right route. The audit identifies the optimal combination of measures, the subsidy rates are better, and the resulting renovation is more likely to achieve the target DPE class than a series of disconnected single-measure installs. The audit generally costs 400-800 EUR and is itself partially subsidised. For an expat owner navigating the process, working with a mandataire who handles the ANAH application is strongly recommended.

What should I do first?

The practical starting point for any property sitting at E, F, or G is a proper DPE assessment if you don't already have a current one, followed by an audit énergétique if you're planning a multi-measure renovation. The DPE tells you where you are. The audit identifies the measures, in order of impact and cost-effectiveness, that will move you to the target letter.

Without the audit, there's a real risk of spending significant money on a measure that improves the score by one sub-letter without crossing a class threshold, while a less intuitive measure would have achieved the jump to the next letter. The audit removes that guesswork.

If you own a rental property on the Côte d'Azur that is currently F-rated or worse and you haven't started this process, the 2028 deadline leaves meaningful but not unlimited time. A multi-measure renovation with MaPrimeRénov' parcours accompagné typically takes 12-18 months from audit to completion, accounting for subsidy application processing and contractor scheduling. Starting in 2026 or early 2027 is feasible. Starting in late 2027 is a risk.

How to improve your DPE rating: moving a Riviera property from F to C