A load-bearing wall that was thought to be removable, a poorly marked evacuation column on the plan, a quote that skyrockets because the ground hides a non-compliant slab: most failures in interior design do not stem from bad decorative taste, but from a lack of technical preparation. Successfully renovating your home with qualified craftsmen requires framing the project well before the first demolition.
Ten-year insurance for craftsmen: the trap of incomplete checks
It is often checked whether a craftsman has ten-year insurance. It is almost always forgotten to verify that this insurance specifically covers the activity planned on the site. A plasterer insured for the installation of drywall is not necessarily covered for waterproofing under tiles or the load-bearing structure.
The ten-year certificate must correspond to the exact activity performed, not just to the existence of a contract. This certificate must be attached to the quote and the invoice. If it is missing or if the title of the covered works does not match the ordered service, the project owner finds themselves without recourse in the event of structural damage.
In practice, before signing, request the up-to-date certificate, read the “guaranteed activities” section, and compare it with the quote description line by line. By entrusting the renovation of the house with craftsmen listed on specialized platforms, this verification is often facilitated by the centralization of documents.
Energy renovation and MaPrimeRénov’ aids: what has changed in 2026
Many interior renovation projects include an energy component (replacement of windows, attic insulation, change of heating system). The calculation of the budget directly depends on the available aids, which have been significantly refocused.
Works still eligible for aids
As of September 2026, the actions still covered by MaPrimeRénov’ remain limited. Heat pumps, certain connections to a heating network, energy audits, and the removal of an oil tank are among the items maintained. Amounts are significantly reduced compared to previous years.
The blockage related to gas heating
One point that competitors do not address: keeping gas heating can now block a subsidized major renovation. If the overall project includes a request for MaPrimeRénov’ funding in a supported pathway, the presence of a gas boiler kept in service can render the file ineligible.
Before launching a project combining interior renovation and energy renovation, check the compatibility of the existing heating system with the targeted aid pathway. This may change the order of work or require a boiler replacement not initially planned.
Site coordination among multiple trades
Demolishing a partition, moving a water point, redoing the electrical installation, and laying a new floor covering: four interventions, potentially four different craftsmen. The real risk is not the individual competence of each, but the sequence of interventions.
A plasterer who intervenes before the electrician has run their conduits forces the walls to be reopened. A tiler who lays tiles before the screed is completely dry creates cracks within three months. The order of intervention conditions the final quality as much as the choice of materials.
For a project affecting the structure or layout of several rooms, time and money can be saved by appointing a single contact person to coordinate the schedule. This can be a project manager, an interior architect, or a general contractor. The coordination cost is recovered through reduced rework and delays.
- Establish a sequenced intervention schedule with drying margins between each batch (screed, plaster, paint) to avoid rework
- Plan a weekly site meeting with all craftsmen present on site, even for five minutes, to realign any discrepancies
- Require each craftsman to sign an interim reception report before the next trade’s intervention
Interior renovation quotes: reading beyond the total amount
Comparing three quotes based solely on the final amount is the most common and least reliable reflex. A low-priced quote that does not detail the supply, labor, and waste management almost always hides additional costs during the project.
An exploitable quote must separate each item: demolition, debris removal, supply of materials (with precise references), labor by batch, and possibly equipment rental. A quote without material references prevents any real comparison.
- Check that the quote mentions the brand and exact reference of the main materials (tiles, joinery, electrical equipment)
- Check for a line “site waste management” with the planned disposal method
- Ensure that execution deadlines and penalties for delays are clearly stated
- Ask whether the quote includes or excludes the preparation of supports (screeding, moisture treatment, stripping of walls)
Feedback varies on this point, but the preparation of supports often represents a significant part of the total budget. A quote that omits it is not cheaper: it defers the expense to an amendment once the project is underway.
Living space and work declaration: do not forget the administrative aspect
Modifying the interior layout without affecting the floor area generally does not require prior declaration. However, as soon as one converts attics, creates a mezzanine, or transforms a garage into a living space, the living area increases.
Beyond a certain threshold of created area, a building permit replaces the simple prior declaration. And in some municipalities, the use of an architect becomes mandatory. Starting work without this verification exposes one to a work stoppage and costly compliance.
Before any intervention modifying volumes or the purpose of a room, a visit to the town hall or a consultation of the local urban plan avoids this type of blockage. The qualified craftsman knows these constraints, but the administrative responsibility remains with the owner.
