Energy certificate problems faced by owners of homes built before 1948 – including many stone-built and character properties – could be eased by a bill that has received support in the Senate.
The
proposal aims to revise rules governing the diagnostic de performance
énergétique (DPE) audit and address a perceived bias against older homes.
DPE
certificates, rated from A (most efficient) to G, assess a property’s energy
use and greenhouse gas emissions.
When initially introduced in 2006, they were based on the
previous year’s energy bills.
However, concerns over accuracy and suspected
fraud led the government to adopt a new calculation method in 2021.
Older homes penalised
The current
system, based on building regulations in place since 1948, involves inspectors
filling out computerised forms, listing factors such as the types of heating,
amount of insulation in the roof and on walls, and whether windows are
double-glazed.
However, as Gilles Alglave of Maisons Paysannes de France told
The Connexion, the software fails to account for features common in older
homes, such as thick stone walls and traditional insulating materials including
mud, lime and straw.
As a result, many rural homeowners feel their properties
are unfairly given low ratings.
Buyers are placing growing importance on these
scores, with homes rated F or G – often called passoires thermiques (‘heat
sieves’) – viewed as costly to heat and environmentally unfriendly.
A study by
property website SeLoger.com found that homes rated F or G sell for, on
average, 15% less than those rated D. Sellers of poorly rated homes are also
more likely to face price negotiations.
In addition, G-rated properties are
already considered unfit for rental.
This is set to expand to F-rated homes
from 2028 and E-rated from 2034 DPE certificates, valid for 10 years and
costing around €200, are mandatory for selling or renting a property.
In
addition, owners of homes rated E, F or G must commission an energy audit –
costing approximately €700 or more – to outline the improvements needed to
raise the rating.
Mr Alglave said that owners of older homes are often advised
to put insulation in the roof and on the interior walls.
However, this can
cause problems with rising damp, and subsequent mould infestations in these
types of property.
“Lots of the charm of old houses is lost if their stones are
covered with polystyrene insulation foam, which itself is very bad for the
environment,” he added.
Maisons Paysannes de France helped sponsor research,
conducted by statelinked agencies, into the real energy efficiency of older
homes across various regions of France.
The findings revealed that some
properties rated F or G had energy use and emissions comparable to more modern
homes rated C or D.
“These homes are often energy efficient, but in a very
different way from newer buildings,” said Mr Alglave.
“For instance, the thick
stone walls of older houses have thermal inertia, meaning they resist
temperature changes – something thinner concrete walls don’t offer. In summer,
these homes stay cool longer, and in winter, the stored heat keeps them warm.
But this inertia isn’t factored into the DPE at all.”
He also gave the example
of a preference in the current laws for replacing old wooden windows with new
ones made from PVC.
“Afterwards, I have heard people say suddenly their houses
are damp and they do not know why.
“Wooden windows made by craftspeople who
know what they are doing always have some ventilation to let humidity out but
factory-made PVC windows are airtight. Installing them in old buildings can be
disastrous.”
Drive to insulate old homes is 'absurd'
The proposed law calls for DPE assessments to take into
consideration heat insulation factors unique to old houses, ensuring
recommended upgrades respect their specific constraints and preserve
traditional construction.
It also states that rental bans on low-rated
properties should not apply if improvements are technically, architecturally or
financially unfeasible due to heritage or cost concerns.
One of the senators
who helped push the bill through the Senate, Sabine Drexler (Haut-Rhin) said
old buildings made up much of the “charm and beauty of France as we know it.
“It is absurd that we are now giving grants to stick polystyrene panels on
stone walls, which will cause so much humidity that in 15 years there will be
no choice other than to demolish the buildings,” she said.
“This is an
important battle. Your readers should talk about it and ask their elected
representatives to act.”
Since the bill was handed over to the lower house, the
Assemblée nationale, it has not been put on the agenda for further discussion.
A scheduling clerk could not confirm when this might happen but Mr Alglave is
optimistic about the political will for change.
“Parts of Paris are now
uninhabitable during heatwaves such as the one we experienced earlier this
summer, even in flats with good DPE certificates. But people owning old
buildings in the countryside with terrible DPE ratings were comfortable because
of the way these houses were built.
“Party politics in the Assemblée nationale
is now destructive, but this is one area where everyone can be constructive.”
Senator Drexler said local initiatives sometimes exist in which architects give
free advice on energy renovation to owners of old buildings, so DPE ratings can
be raised without damage.
Maisons
Paysannes de France also advises members on respectful renovations
(maisons-paysannes.org).
Ways of boosting a DPE can include eco-friendly
heating systems, such as air to water or geothermal heat pumps, or
high-performance wood or biomass burning stoves, as well as controlled
mechanical ventilation systems.
Help towards renovation includes the
MaPrimeRénov’ grant, interest-free eco-loans from banks, and the coup de pouce
chauffage scheme that can help towards replacing old heating systems.
Free
advice on funding can be obtained from the France Rénov network.
From January, DPE rules are expected to be
modified so homes heated by electricity are no longer penalised compared to
gas-heated homes. In some
cases their rating should rise.
