In an effort to cut down France’s huge energy bill and
dependence on electricity in 2012 new building thermal regulations came into
force. These target 3 main areas : the
bioclimate of the building (thermal performance), primary energy consumption
and summer indoor temperature. To do
this constructors have to look at orientation, heating systems and building
materials – it is really a “fabric first” approach requiring high levels of
insulation.
On a practical level for us we, this meant we couldn’t have
our original hand drafted plans as the orientation towards the sun wouldn’t
work, we have a LOT of rockwool
insulation (on reflection in the pursuit of a healthy house I wish we had used sheep’s
wool) as well as blown cellulose in the loft space. We have triple glazing – something that was
integral to the build for my husband.
One part of our roof is a green roof, although that was more of an
aesthetic approach – the additional insulation was a bonus.
We had quotes for various kinds of heat pumps but felt that
as the house is super insulated we would not get the return on investment of
one. The regulations state that there
are certain appliances that you do have to have – for example you cannot just
have an ordinary water heater but one that is “thermodynamique” – it uses the
calories in the air around it to heat the water. In addition as we were creating a largely
airtight house (few windows open) we had to put in a heat recovery and exchange
system (VMC double-flux). These were
non-negotiable as they formed part of our heat survey (étude thermique) included in planning permission. The respect of the étude thermique is
paramount, as they show that the house
will be low energy consumption or BBC
(batiment basse consumption). We face
fines if it is not and also the non-allocation of our PTZ – 0% interest loan
from the government, which in our case is nearly 30,000€ so would be very hard
to find if we are not compliant.
At the end of the build you have to provide a certificate to
the planning department to show that the work that has been done is inline with
what was given in the étude thermique.
Initially it is a paper exercise,
our builder will send information regarding the construction methods and
material used to the company that provided the étude thermique who will say
whether it matches or if there is divergence.
In the case of divergence or just as a matter of random checks, the
planning department can implement a level 2 study – still a paper exercise but
carried out by them. They can ask for
full details on the build. Finally, if
they are still not happy they can demand a full inspection. Again our PTZ hangs on this certificate as it
is the proof that we have a BBC house.
Listed below are some websites that provide more information
regarding RT2012.
http://www.gasinfocus.com/en/focus/french-thermal-regulation-rt-2012/
