Which works are the most effective for my energy renovation?

The Climate and Resilience Act of 2021 aims to move towards an entire housing stock with better energy performance! With this in mind, and in the face of soaring energy prices and regulatory changes on energy sieves, energy renovation is no longer an option but a real necessity!

But first of all, how do you renovate well? Which works can you, as landlords, carry out to achieve the best gains in energy performance?

Why is a home's energy performance so important?

Energy performance is a bit like a health check-up for your property. It can tell you whether your home's ability to retain heat in winter and stay cool in summer is up to scratch, and above all without sending your energy consumption through the roof!

Because yes, an energy-efficient home also means savings. According to Ademe, a poorly insulated house can lose up to 30% of its heat through the roof*: that's huge! You only have to connect this loss with your heating bills… It's easy to see how important it is to insulate your property well to look after your finances.

(*https://www.ecologie.gouv.fr/sites/default/files/documents/guide-pratique-isoler-sa-maison.pdf)

The great benefit is also everyday comfort. No more draughts in winter, no more that suffocating feeling in summer. A well-insulated home is one that maintains a pleasant temperature all year round!

Note that, beyond these benefits, making your property more energy-efficient also means complying with the regulations in force! The bans are tightening for so-called energy sieve homes. G-rated properties have been banned from letting since January 2025, F-rated properties will be in 2028, and this will extend to E-rated properties in 2034.

New regulatory requirements are also emerging. For example, to access certain support such as MaPrimeRénov', providing an Energy Performance Certificate (EPC) will be mandatory. But other measures are already in place, such as for access to the Éco-PTZ: an energy audit is mandatory and must demonstrate a gain of at least 2 energy ratings!

Do you want to find out more about the Éco-PTZ? Feel free to read our article 'The interest-free eco-loan: what changed in July 2025'

Investing in an energy renovation means choosing to enhance your property assets over the long term, and to anticipate future legal obligations.

Aiming for effective works to improve your property's value

We mentioned it in the introduction: the Climate and Resilience Act enacted in 2021 changed the game for landlords.

The aim of this act is to remove energy sieves from the rental housing stock by making them impossible to let.

This regulation will directly affect the asset value of your property! An energy-intensive home will gradually become impossible to let (if it isn't already, as is the case for G+ and G-rated buildings).

A property with an A, B or C energy rating sees its value climb on the property market! Buyers and tenants alike are increasingly sensitive to energy issues, so stack the odds in your favour by offering a comfortable home with controlled bills.

Anticipate future legal obligations and enhance your property assets by opting for an energy renovation of your home!

The priority works for maximum gains

In order to transform your home into an energy-efficient property, you should know that not all works are equal.

The first piece of advice we can give you is to carry out an energy audit so you can benefit from prioritised and costed works scenarios.

Then, the key thing when carrying out your energy renovation is generally to aim to replace ageing equipment and improve the building's thermal envelope. With these two objectives in mind, you're sure to be heading towards a winning combination for optimal overall performance.

RITMODiag goes back over, in more detail, the works that will really make a difference:

Thermal insulation

Insulation really is the absolute priority for improving your home's energy performance. If your house or flat is not properly insulated, you may have the most efficient heating system there is, but you might as well be heating a sieve!

Among the effective works you can carry out to insulate your home thermally, there are:

• Insulation of the loft space or roof. As we briefly mentioned, a poorly insulated roof or loft causes up to 30% heat loss.
• Insulation of the external walls, which can cause up to 20 to 25% heat loss.
• Replacing joinery (doors and windows). One of the biggest misconceptions during energy renovation works is: 'changing the windows can change your energy rating!'. Compared with the roof or walls, joinery accounts for only 10 to 15% of heat loss.
• Insulation of the floor, the lower floor, to avoid further heat loss.

An efficient heating system

Once your property's envelope is insulated, you now need to optimise the air treatment and the heating system. For this, we can only advise you to replace the energy-intensive equipment you have: oil boiler, gas boiler… Opt instead for an efficient renewable-energy system:

• Heat pumps (PAC): the most widely used heating equipment! You can make real savings with an installation of this type. To find out more, as luck would have it, we have just written an article telling you everything about heat pumps !
• Biomass systems: pellet or log boilers or stoves.

Effective ventilation

Effective insulation is great! But it also makes your home more 'airtight'. To avoid damp, mould and other unpleasant surprises, remember ventilation, which is crucial!

• Dual-flow VMC (controlled mechanical ventilation), which ensures indoor air quality by constantly renewing it.

Renewable solutions

It is also entirely possible to go even further with energy performance using other installations such as:

• Photovoltaic panels to produce your own electricity and cover part of your needs.
• PVT systems (hybrid photovoltaic and thermal) to combine the production of electricity and heat.

All these renovation works will allow you to optimise your home's energy performance as effectively as possible. But of course, all this comes at a cost. Good news! Financial support exists.

The financial support you can benefit from for your home's energy renovation

You are not alone in financing your home's energy renovation works! The State, but also other organisations, offer support depending on your income and your renovation project.

The main forms of support to push you towards better energy performance are:

• MaPrimeRénov': available to all owners, the amount depends on your income and the nature of the works,
• Energy Savings Certificates (CEE): a bonus financed by energy suppliers; here too the amount varies according to your works and your income,
• The interest-free eco-loan (Éco-PTZ): lets you take out an interest-free loan to finance your works. This support can be combined with MaPrimeRénov'!

However, bear in mind that, like the regulations, the support schemes can change over time. This is particularly the case for MaPrimeRénov', which has undergone significant adjustments since 2025. The scheme focuses on the most energy-intensive homes (rated E, F or G) and the most modest households.

In 2026, certain types of works are set to be excluded and will no longer be eligible under the single-measure pathway. This is the case for façade wall insulation and the installation of biomass boilers. If you are considering these works, it's now or never!

To end on a positive note: the option of carrying out insulation works without being required to change your heating system at the same time in order to access the MaPrimeRénov' pathway has been extended until 31 December 2026!

Your renovation project: the expertise of a consultancy

Before any works, it is strongly recommended to have an energy audit carried out by a property survey consultancy with certified auditors. It is even mandatory for certain homes or to benefit from certain support schemes!

With this in-depth analysis, which precisely identifies the sources of energy loss and proposes a specific, prioritised and costed renovation works scenario, it is easier to visualise the works to be carried out and to get started!

The support of a qualified professional allows you to target the works that will have the most impact and that are best suited to your home and your budget.

Contact RITMODiag to find out more about the support we offer!

Energy renovation is a strategic investment for improving the value of your property assets. Between regulatory changes, the eligibility for support that can change, and all the technical choices, getting support is strongly advised.

Our certified surveyors and auditors support you through the stages of your renovation towards better energy performance.

Contact RITMODiag today to find out more about our services and offers.

Together, let's transform your home into an energy-efficient property!