Long perceived as a mere formality, the Energy Performance Certificate (EPC) has become, following its 2021 reform and subsequent strengthening under the Climate and Resilience Act, a key criterion when valuing and selling a property. For owners of period apartments and heritage buildings, it is therefore essential to understand how to improve an EPC rating without compromising the architectural heritage. Here are the key factors to consider.
Improving your EPC: a game-changing factor when selling a luxury property
A poor EPC rating is not merely an inconvenience: it is a genuine obstacle to selling a property. Buyers, who are increasingly well-informed, factor energy performance into their financial decision-making, alongside location and the property’s overall condition. This shift in buyer behaviour has a measurable effect on the impact of EPCs on the property market, particularly in the premium segment, where buyers now negotiate prices based on the estimated cost of the work required.
The issue is all the more pressing given that the 2021 EPC reform made the assessment clearer and more relevant, while also imposing greater obligations on property owners: EPCs became legally enforceable and, for landlords, the reform paved the way for the gradual ban on renting out energy-inefficient properties. These are all reasons to consider improving your EPC before putting a property up for sale or rent.
Understanding the information on the EPC energy label before taking action
Before undertaking any work to improve a property’s energy performance, it is important to identify its current shortcomings and the most appropriate renovation options. In this respect, the EPC takes several technical criteria into account: the quality of the insulation (walls, roof, windows), the performance of the heating and domestic hot water systems, as well as the efficiency of the ventilation system.
It is worth noting that in older properties, thermal insulation is very often the most penalising factor, due to original materials that perform poorly by today’s standards – particularly in buildings constructed before the introduction of the first French thermal regulations in 1974.
A certified energy assessor (or a qualified architect, engineering consultancy, authorised RGE professional, etc.) can carry out a detailed energy audit, assessing each area individually and prioritising improvements according to their actual impact on the energy rating. This step helps avoid costly work that delivers little benefit in terms of the desired improvement in the property’s rating. In this respect, it is useful to refer to the current EPC regulations to understand precisely the energy consumption thresholds associated with each rating, from A to G.
The three key ways to improve your EPC
Thermal insulation as the top priority
In an older property, the roof, walls and windows account for most energy losses. These are therefore the areas to address first, even if the work needs to be carried out in stages to preserve original architectural features such as mouldings, parquet flooring and listed façades. A well-designed internal insulation solution can often combine improved energy performance with respect for the property’s character, while resulting in only a minimal loss of floor space.
A heating system suited to the building
Once the insulation has been addressed, replacing an outdated heating system becomes a sensible next step. Renewable energy solutions (such as heat pumps or wood-burning heating systems) are currently among those most highly valued in EPC calculations, subject to compatibility with the condominium or planning constraints that may apply to heritage properties.
Ventilation: an often-overlooked area for improvement
The final link in the EPC improvement chain, ventilation nevertheless plays a key role in ensuring the comfort and long-term effectiveness of the previous work. An efficient mechanical ventilation system helps limit humidity and the associated energy losses, while also improving indoor air quality. This can be a significant advantage for clients with high expectations when it comes to quality of life.
What budget should you allow for, and what improvement in EPC rating can you expect?
The cost of a comprehensive energy renovation varies significantly depending on the property’s size and initial condition, with costs potentially reaching several tens of thousands of euros for a full renovation. However, it is not always necessary to undertake a complete renovation: for some properties, a targeted intervention, such as replacing windows or upgrading the heating system, may be enough to move up one rating category and have a measurable effect on the property’s valuation.
It is also worth noting that financial assistance is available: several schemes (MaPrimeRénov’, the zero-interest eco-loan and reduced-rate VAT) can help reduce the overall cost, subject to eligibility conditions.
Once the work has been completed, a new assessment should ideally be carried out to officially confirm the rating achieved. The cost of this assessment is added to the cost of the property diagnostics required when selling or renting out the property.
Please note that even if you make no changes to the property’s energy performance, you must take into account the validity period of the EPC, which is set at ten years, before putting the property up for sale or embarking on a rental project.
Improving your EPC: results that make a difference in the property listing
Beyond enhancing the property’s value, an improved EPC rating has a tangible impact when the property is marketed. The EPC rating in a property listing is mandatory and provides an immediate signal to potential buyers, helping shape their decision even before arranging a viewing. For exceptional properties, where every detail matters, this information now complements other criteria such as architecture, location and amenities.
However, improving an EPC rating requires a good understanding of the specific characteristics of older buildings. If you are considering selling, do not hesitate to seek advice from our agencies to help you prepare your project effectively.
