A property project often commits you to several years of income. Whether you’re looking to buy a home, sell a property or renovate an apartment, every decision made upfront affects the final outcome—sometimes irreversibly. Understanding the factors that influence the price, financing and renovation work can help you avoid costly mistakes.
Energy ratings and co-ownership: two factors that can change a property’s value
Before discussing budgets or mortgages, one point deserves the full attention of both buyers and sellers: the energy performance certificate (DPE). This document is more than just a letter on a listing. It determines whether a property can be rented out and increasingly affects its sale price.
Notaires de France notes that the increase in sales of homes with better DPE ratings does not necessarily reflect a genuine improvement in the housing stock. Changes to the calculation method, particularly for homes under 40 m², partly explain this trend. If you compare an assessment carried out five years ago with a recent DPE, the ratings are not always comparable.
Thinking of buying an apartment in a co-owned building that needs renovation? Review the minutes of general meetings before signing. Energy-efficiency upgrades to a unit in a co-owned building depend on collective decisions about the roof, façade and shared heating system. A vote against the work at a general meeting can block a renovation project, even if the owner has the budget. Individual improvements to windows or internal insulation are not always enough to change the home’s DPE rating.
On Dekortikon’s real estate section, these issues are regularly explored through practical examples that help you anticipate this kind of obstacle.
Borrowing capacity and the true cost of buying property
Have you ever noticed the difference between a property’s asking price and what it actually costs? The purchase price is only part of the investment. Several additional expenses can significantly affect the final budget.
Work out your borrowing capacity before you start looking
Borrowing capacity is the maximum amount a bank is willing to lend. It is based on a simple calculation: regular income minus fixed expenses. The result determines the monthly payment you can afford and, in turn, the total loan amount.
Knowing this figure early in the process has two benefits. It helps you focus your search on properties within your budget. It also saves time by avoiding viewings for homes you can’t afford, in a market where acting quickly matters.
Costs to factor in beyond the sale price
The budget for a property purchase includes much more than the price agreed with the seller. Here are some commonly underestimated costs:
- Notary fees, which make up a significant share of the total cost for an existing property and are considerably higher than for a new-build
- Mortgage security fees (mortgage or guarantee), which vary depending on the provider and the amount borrowed
- The cost of any renovation work, which should be estimated before signing the preliminary sales agreement so you can adjust your offer
- Ongoing co-ownership charges and calls for contributions toward approved or upcoming work
A realistic budget includes these costs from the outset, not after the preliminary sales agreement has been signed.
Selling a property: how to set the right price
When selling, it is still common to be tempted to overprice a home. Notaires de France describes a resale market that regained momentum after the recovery began in autumn 2024, but that recovery has now levelled off.
Why does this matter? Because an overpriced property can sit on the market for a long time when the market has levelled off. Every extra week on property portals sends a negative signal to potential buyers. Setting the right price from the outset attracts more serious viewings than gradually reducing it after several months.
Comparing your property with recent sales in the same area remains the most reliable way to set a price. Notarial databases provide access to actual transaction prices, not asking prices. National trends say little about local market conditions: one neighbourhood may be gaining value while the city as a whole remains flat.
Energy-efficiency renovations: plan ahead for grants and changes
Property owners undertaking renovation work must navigate a system of grants that changes regularly. Eligibility requirements for grants can change while you’re planning a project. The amount estimated at the start may be reduced if the rates change between the application and the start of the work.
This risk is particularly relevant for lengthy renovations or projects in co-owned buildings, where several months can pass between approval of the work and its completion. To be on the safe side, don’t build a financing plan that depends entirely on a grant whose amount has not yet been confirmed.
Check that contractors’ RGE certification is valid
To qualify for most public grants, the work must be carried out by an RGE-certified contractor (Recognized Environmental Guarantor). The French government can now suspend this certification for certain professionals. Checking that the RGE certification is valid when you sign the quote can help you avoid an unpleasant surprise when you apply for the grant payment.
Three practical checks to make before starting renovation work:
- Check the grant amounts in effect when you submit your application, not when you receive your first quote
- Check each contractor’s RGE status in the official directory, even if the work is due to start several months after the quote
- In a co-owned building, make sure any necessary shared work has been approved before committing to additional individual expenses
A successful property project depends on carrying out practical checks at every stage. The DPE, borrowing capacity, sale price and renovation grants are four factors that, if misjudged, can turn an opportunity into a financial trap. Cross-checking local data against your personal circumstances remains the best way to assess any decision before you make it.
