Transforming an interior is no longer just about choosing flooring or a paint color. Since September 2026, the rules for financing renovation work have changed: public aid now favors comprehensive renovations over isolated interventions. This shift alters the way a renovation project is conceived, requiring a blend of aesthetics, energy performance, and regulatory constraints from the sketch phase.
Major Renovation and Energy Performance Certificate (DPE): What Inspirational Projects Don’t Show
Before-and-after project galleries highlight volumes, light, and materials. They overlook a crucial parameter that has become structural: the energy rating of the home before work. A major renovation journey requires a home rated E, F, or G, an improvement of at least two DPE classes, and at least two categories of building envelope insulation.
In practice, a project that combines the removal of partitions, kitchen refurbishment, and window replacement can become eligible for significant aid, provided it includes effective insulation. Conversely, a purely decorative project, no matter how ambitious, will not trigger any public funding.
This framework encourages simultaneous consideration of insulation, heating, and hot water production rather than focusing solely on aesthetics. To explore renovation projects on Murmures Déco, this holistic logic is clearly evident in the documented achievements.
Interior Work Eligible for Aid: Comparative Table by Project Type
Not all interior renovation projects are equal in terms of funding. The table below contrasts common interventions based on their potential eligibility for the schemes in place since September 2026.
| Type of Interior Project | Impact on DPE | Eligibility for Major Renovation |
|---|---|---|
| Kitchen reconfiguration with insulation of peripheral walls | Potentially significant | Yes, if coupled with at least two insulation measures |
| Removal of partitions without touching the envelope | None | No |
| Window replacement and attic insulation | Measurable gain | Yes, subject to initial rating conditions |
| Bathroom refurbishment with change of hot water production | Variable depending on the chosen equipment | Possible if integrated into a bundle of work |
| Painting, coverings, decoration only | None | No |
The reading of this table reveals a clear gap: projects that affect the building envelope open up funding possibilities, while others do not. An interior designer who incorporates this data from the design phase can steer the project toward a funded scenario without sacrificing aesthetic ambition.
Gas Heating and Interior Renovation: A Game-Changing Constraint
Retaining gas or oil heating can now block a funded major renovation. This point, often overlooked in decoration magazines, has direct consequences on the budget of an interior renovation project.
Specifically, a homeowner wishing to renovate an apartment rated F with a gas boiler will need to plan for the replacement of this equipment to access the funding scheme. The heating system becomes a lever for financing the rest of the project, not just a technical issue relegated to the end of the program.
This constraint redistributes priorities. In a complete reconfiguration project, the choice of heating system comes before that of the kitchen layout or bathroom tiling. The best-designed projects integrate this sequence from the preliminary study.
Three Criteria to Check Before Launching a Mixed Decoration and Energy Project
- The current DPE rating of the home: without an E, F, or G label, the major renovation journey is inaccessible, and the project relies entirely on self-financing
- The nature of the existing heating system: a gas or oil appliance requires its replacement to unlock aid, which alters the overall project budget
- The date of submission: regulatory changes apply to applications submitted from September 1, 2026, the date of signing the quote is not enough to preserve the old conditions
Successful Renovation Project: Articulating Decorative Ambition and Measurable Performance
The most convincing achievements do not choose between a transformed interior and an improved energy balance. They overlap both objectives within the same project. A reconfiguration of a living space that integrates internal insulation of the peripheral walls gains thermal comfort without losing habitable volume, provided that thin, suitable insulators are used.
The replacement of joinery, often considered for aesthetic reasons (switching to thinner windows, adding sliding glass doors), directly contributes to the gain in DPE classes. A well-sized sliding door improves both brightness and thermal performance.
The bathroom renovation illustrates this dual logic well. Replacing a bathtub with an Italian shower falls under interior design. Coupling this intervention with the installation of a thermodynamic water heater transforms the project into an eligible operation, provided that the rest of the program meets the required threshold.
What Distinguishes a Coherent Project from a Catalog of Good Ideas
- An energy diagnosis conducted before any design decisions, to identify priority areas to address
- A timeline that places the submission of the aid application before the start of the work, not the other way around
- A budget envelope that includes energy-related items from the outset, rather than adding them as optional variants
- Monitoring by a certified advisor, required for the major renovation journey
Renovation projects that leave a lasting mark on an interior are those that have been conceived as a whole. A well-sequenced project can finance part of its aesthetic transformation through energy savings. This articulation between what is visible and what is measurable remains the main lever for transforming a home without increasing the final bill.
