An F-rated apartment has just been purchased for a rental project. The renovation costs are estimated, the energy performance certificate (DPE) needs to improve, and the budget is already tight. Optimizing renovation costs for a rental investment in 2026 does not mean skimping on the quality of materials. It involves making choices between different work areas, aligning the schedule with available aid, and avoiding expenses that do not change either the rent or the attractiveness of the property.
MaPrimeRénov’ Reform September 2026: What Changes for Landlords
As of September 1, 2026, the “by gesture” pathway of MaPrimeRénov’ has been restricted. Isolation alone, ventilation alone, replacement of a single piece of equipment: these small projects are no longer eligible individually for landlords. Decree No. 2026-822 of August 25, 2026, now requires going through a comprehensive renovation to access the aid.
In practical terms, a landlord who planned to change the windows this year and then insulate the attic the following year loses the grant for each separate action. They must group the work into a single comprehensive project to remain eligible.
Another constraint: in single-family homes, retaining a gas or oil heating or hot water system may block access to MaPrimeRénov’ for the comprehensive pathway. Exploring renovation alternatives with tousrenov.be allows for comparing comprehensive project scenarios before finalizing a work plan.
This reform changes the budgetary logic. Spreading the work over several years now costs more than concentrating the investment, because each isolated action is 100% self-financed.
Priority Work Based on Their Impact on the DPE and Rent
Not all renovation areas are equal. Some can improve the DPE rating by one letter, while others enhance comfort without changing the energy class.
Properties rated F or G are subject to rent freezes under the Climate and Resilience law. As long as the DPE remains at F or G, there is no revision to the IRL, and no increase between two tenants. A DPE that improves from F to D unlocks the ability to set a rent consistent with the market.
Here are the areas to prioritize:
- Thermal insulation (walls, roof, windows) takes up the largest part of the budget, but it is the main lever to gain one or two letters on the DPE. Without proper insulation, changing the boiler is not enough to move out of class F.
- Replacing the heating system with a heat pump or a high-performance unit complements insulation and is a condition for accessing MaPrimeRénov’ under the comprehensive pathway since September 2026.
- Controlled mechanical ventilation (VMC) is often overlooked. It represents a modest cost, but its absence can degrade the recalculated DPE and cause humidity issues that drive tenants away.
- Interior modernization work (painting, flooring, kitchen) has no effect on the DPE. They make the property more attractive but do not unlock any aid or regulated rent increase.
The simple rule: first the work that changes the DPE letter, then those that attract tenants. Reversing this order means spending on visual comfort without being able to adjust the rent.
Case of Properties in Tight Zones
In tight zones, rent increases after renovations are regulated and subject to strict conditions regarding the amount of work done. In regulated areas (Paris, Lyon, Bordeaux), the rent cannot exceed the increased reference rent, even after significant renovations.
Before budgeting, it is essential to check the zone of the property. An investor who spends heavily on renovations in Paris without consulting the increased reference rent risks never recouping their costs through rent increases.
Work Schedule and Cost of Delaying for a Rental Property
A project delayed “to spread the expense” often ends up costing more. In rental investment, the cost of delay is not limited to material inflation.
An F or G-rated property can no longer be rented starting from the deadlines set by the Climate law. Delaying the renovation of a G-rated property means accepting a total vacancy period, with no income. The loss of unpaid rent for several months often exceeds the extra cost of starting a project earlier.
For F-rated properties, the deadline is approaching. An investor who waits until the last moment to start work finds themselves competing with all other landlords pressed by the same timeline. Qualified RGE artisans, already in demand, increase their lead times and sometimes their rates.
Group Work Areas to Reduce Fixed Costs
Each mobilization of a project generates fixed costs: scaffolding, project setup, coordination between trades. Grouping insulation, heating, and ventilation into a single project reduces these fixed costs and simplifies the MaPrimeRénov’ application.
A grouped project also allows for ordering only one DPE after the work, instead of having to redo a diagnosis at each stage. The cost of the DPE is modest, but the administrative time savings are significant.
Property Deficit and Deduction of Work from Rental Income
The property deficit remains an underutilized tax lever by investors who renovate. The principle: when deductible expenses (including maintenance, repair, and improvement work) exceed rental income, the deficit can be deducted from global income up to a certain annual limit.
For a landlord undertaking significant work, this deduction can absorb a significant part of the net cost of renovation. The work eligible for the property deficit is not the same as those covered by MaPrimeRénov’. Combining public aid and property deficit on different work areas increases the reduction of the actual cost.
Note: combining MaPrimeRénov’ and tax deduction on the same work area is not allowed. Expenses must be allocated between the two systems, item by item, with separate invoices. An accountant or wealth manager can structure this allocation before the project begins.
The renovation budget for a rental investment in 2026 is not read line by line on a quote. It is read by cross-referencing the DPE gain, the potential rent increase, the available aids, and the net tax cost after deduction. A well-structured project, launched at the right time, costs less than a project divided into phases under the guise of caution.
