A property project hinges on three technical trade-offs that general guides rarely address together: choosing a construction method that meets thermal requirements, sequencing financing around available grants, and planning the stages between new construction and renovation of existing buildings. Every decision made upfront affects the property’s overall cost and energy performance for decades to come.
RE2020 and the 2028 milestone: anticipate thermal requirements from the design stage
The 2028 RE2020 milestone is in preparation, but its parameters have yet to be confirmed. For a new-build project launched today, the risk is delivering a building that meets current thresholds but already falls short of future carbon requirements.
We recommend asking the designer to compare two scenarios: one based on the current RE2020 thresholds, and another that builds in a safety margin for the Ic construction indicator. This margin mainly concerns the choice of structural materials (low-carbon concrete, timber framing, or clay brick with integrated insulation) and the heating system.
Air-to-water, water-to-water and geothermal heat pumps remain eligible for grants, which naturally guides the choice of heating system. If the thermal system is undersized on a new-build project, this could lead to additional compliance costs if the 2028 milestone tightens requirements for non-renewable primary energy.
A project manager or thermal engineering consultancy able to provide a dynamic thermal simulation (STD) from the preliminary design stage remains the best investment at this point. The cost of this study represents a fraction of the overall budget, while helping secure all subsequent technical decisions.
Energy renovation: choosing between individual upgrades and a comprehensive renovation
Buyers taking on an older property that needs work face a major decision. Individual upgrades cost less in the short term but limit access to the most generous grants. A coordinated, comprehensive renovation can deliver an improvement of several EPC rating bands and qualify for higher grant amounts, but requires more cash flow and more extensive project management.
Grants for individual upgrades have been refocused. Some measures, such as high-efficiency gas boilers (THPE), are no longer covered by MaPrimeRénov’. Professionals involved in construction and property development with Cyber Immobilier track these regulatory changes to guide technical decisions from the outset of the application process.
Combining funding schemes for renovation work
Other schemes may still help fund work not covered by MaPrimeRénov’. Energy savings certificates (CEE) remain available for several measures, including loft insulation, window replacement and the installation of high-performance ventilation systems.
- The zero-interest eco-loan can finance up to a variable limit depending on the number of measures carried out, with no income requirements, and can be combined with MaPrimeRénov’.
- Reduced VAT applies to labour and materials for homes completed more than two years ago, lowering the out-of-pocket cost of measures that do not receive a grant.
- CEE certificates can be negotiated with different obligated parties (energy suppliers), and the amount varies depending on the provider selected. Comparing several offers before signing the quote is a step that is often overlooked.
This combination should be assessed on a case-by-case basis. An energy audit carried out by an RGE-certified professional, which is mandatory for comprehensive renovations, helps quantify the expected savings and optimise the financing plan.
Land and budget: costs to weigh up before applying for planning permission
Land accounts for a varying share of the total budget depending on the location. Two technical factors are often underestimated when searching for a plot: soil conditions and access to utility networks.
A G2 AVP geotechnical survey, carried out before submitting the planning application, determines the choice of foundations. On clay soil subject to shrink-swell movement, the additional cost of suitable foundations (reinforced footings, a raft foundation or micropiles) can account for a significant share of the structural work budget. Leaving this out of the initial budget creates a gap between the forecast and the actual cost.
Prioritise features with lasting value
When the budget is tight, three technical features offer the best return on resale and everyday comfort:
- The thermal envelope (wall and roof insulation, windows and doors): this is the most difficult and expensive feature to upgrade after handover. Getting it right at the design stage avoids the need for energy renovation in the medium term.
- The ventilation system: a correctly sized heat-recovery ventilation system (MVHR) improves indoor air quality and reduces heat loss, but requires ductwork to be planned from the outset.
- Electrical wiring and home automation: installing conduits and provisions for a smart electrical panel costs little during construction but becomes expensive during renovation.
Decorative finishes are easy to update: they can be changed later without affecting the structure or reducing performance.
Information requirements and choosing renovation professionals
Energy renovation professionals must inform their clients about the France Rénov’ public service. This requirement provides a practical way to check regulatory compliance when selecting contractors.
A contractor or project manager who does not mention France Rénov’ as part of their sales process is not meeting their obligations. This simple criterion can help screen providers before you even compare technical quotes.
The professional’s RGE certification determines eligibility for public grants. Signing a quote with a company that is not certified for the relevant type of work rules out access to MaPrimeRénov’ and CEE certificates for that work, even if the work itself is technically identical. Checking that the certification is valid in the official directory before making any contractual commitment is a basic precaution, yet its omission leads to rejected applications every year.
Planning the stages between new construction and renovation, combining multiple funding schemes, and choosing compliant professionals form a three-part technical framework. Any weak link can mean extra costs or lost grants. Structuring these three areas from the outset remains the best way to keep the budget under control and ensure lasting performance.
