What expense items distinguish a controlled renovation site from a project that goes off the rails? Between the recent developments of MaPrimeRénov’, the regulatory constraints on energy-inefficient homes, and the choice of craftsmen, the variables to assess before starting real estate work are more numerous than they seem. This article compares the key data to arbitrate each stage of a renovation or construction project.
MaPrimeRénov’ Reform September 2026: What Remains Fundable
Since September 1, 2026, decree n° 2026-822 of August 25, 2026, has refocused the MaPrimeRénov’ process by action. Several common works are no longer eligible when carried out alone: wall insulation, window replacement, ventilation, wood or pellet stoves, thermal solar equipment.
On the other hand, certain heat pumps, connection to a heat network, and the removal of an oil tank remain funded through this process. For individual homes, retaining gas or oil heating after work excludes any significant aid.
| Type of Work | Eligible for MaPrimeRénov’ by action (since Sept. 2026) | Eligible for extensive renovation |
|---|---|---|
| Isolated work (walls, attics, windows) | No | Yes, if integrated into a multi-item project |
| Heat pump (certain models) | Yes | Yes |
| Wood/pellet stove | No | Yes, under conditions |
| Connection to heat network | Yes | Yes |
| Removal of oil tank | Yes | Yes |
| Gas/oil heating maintained (individual house) | Not applicable | No |
Extensive renovation now requires a minimum gain of two energy classes in the energy performance diagnosis (DPE), a prior audit, and the involvement of Mon Accompagnateur Rénov’. In other words, step-by-step insulation loses its financial interest if it is dissociated from a global project.
To explore the different types of sites and compare the services offered by professionals, the sheets available on the Leader Immobilier travaux site allow for quick cross-referencing of quotes by item.
Real Estate Work Budget: The Most Significant Items
The budget distribution varies depending on whether it is a new construction, a partial renovation, or an extensive renovation. Three items account for most of the project overruns.
Structural Work
Demolition, foundation repairs, opening load-bearing walls: these structural interventions represent the heaviest part of a renovation project. They are also the most difficult to estimate before the diagnostic phase.
A precise inventory, coupled with a recent DPE, reduces the risk of late discoveries (moisture in the subfloor, asbestos, termites). Homes classified as G have already been prohibited from rental since 2025, and those classified as F will be from 2028: thus, the diagnosis also conditions rental profitability.
Networks and Insulation
Electricity, plumbing, thermal insulation: these technical lots frequently generate additional costs when addressed after the structural work without prior coordination. Planning a safety margin on the total budget remains the most documented recommendation based on project feedback.
Finishes and Secondary Work
Floor coverings, painting, interior carpentry, sanitary equipment. This item may seem secondary, but it consumes time and budget if material choices are not finalized before starting.
- Set product references (tiles, flooring, faucets) before signing the quote to avoid amendments during the project
- Check compatibility between existing supports and chosen finishes (a poorly anticipated leveling adds an entire lot)
- Order long-lead materials (custom carpentry, imported tiles) as early as the planning phase
Choice of Craftsmen and Site Monitoring: Practice Discrepancies
The price in the quote is not enough to differentiate two companies. Discrepancies are measured on three criteria that are rarely compared side by side.
The RGE qualification conditions access to public aid. Since the reform of September 2026, a non-RGE certified craftsman excludes the project from any MaPrimeRénov’ process, including extensive renovation.
The guarantee of perfect completion, often unknown, gives the professional one year to correct defects noted upon project reception. This period runs from the receipt report, not from the actual completion of the work.
- Compare at least three detailed quotes item by item, not on a global lump sum
- Require explicit mention of insurances (ten-year, professional liability) on each quote
- Check RGE certification on the official site before signing, as some certifications expire during the project
- Plan regular progress points to detect discrepancies before they become disputes
Logical Order of Work: Sequencing to Avoid Rework
A poorly sequenced site generates costly rework. The logic of progression remains the same regardless of the project’s scale: demolition, structural work, networks (electricity, plumbing, ventilation), insulation, partitions, coverings, finishes.
Reversing two steps, for example, laying a floor covering before finishing the plumbing, exposes one to damages that nullify the completed work. Each lot depends on the reception of the previous lot, and this chain of dependencies must be included in the project schedule.
For projects subject to administrative authorization (prior declaration, building permit), the instruction period adds to the construction schedule. A late submission delays the entire schedule, including delivery.
The reform of renovation aids reinforces this sequencing requirement: a prior energy audit is now mandatory for extensive renovation, which requires knowing the exact condition of the housing before estimating the items. Without this audit, no aid application can be submitted, and the risk of administrative refusal adds to the financial risk of the project.
