The Content Of The Article:

Replace an old window

A change of window is a good way to gain thermal and acoustic comfort and save energy. Nevertheless, this type of work can quickly represent a significant expense, and it is good to know what subsidies and help to ask. Up to 15% of heat losses are through windows, so it is one of the first poles to take into account in the context of work to improve the energy performance of a home.

Why change your windows

Even though the windows of a dwelling may still appear in good condition, it may be worthwhile to consider replacing them if their thermal performance are weak. Indeed, a home loses a large part of its heat through windows, especially if it is large windows that are not exposed to the sun. The installation of new windows, double or triple glazing can save substantially the energy spent to heat the house. These windows will retain the heat inside (the gain is estimated at 3° C) and thus allow to reduce the heating bill. It will be necessary to take into account solar gains that windows can bring, as well as theilluminance of rooms that they can improve. Replacing windows is also a great way to improve the sound insulation of a dwelling.

Enjoy the thermal quality of a window

In case of doubt, a professional can calculate a heat transfer coefficient (Uw) in place. This will give a good indication of the energy performance of the windows. Plus Uw coefficient is low (the lower the number is), the better the insulation of the window.

For which type of window to opt for?

To choose new windows, you have to decide for a type of glazing (double or triple) and for a type of carpentry (PVC window frame, wood or aluminum). The space between the glazing layers and the glass treatment (laminated, treated or tempered) will also have an impact on its energy performance.

Wood, PVC or aluminum for windows?

Between wood, PVC or aluminum, the criteria of choice will often be the aesthetic qualities of the materials and their price. However, everyone has its advantages.

  • For the woodExotic species (cheaper and more resistant to moisture and pests) will be preferred only if they are PEFC or FSC certified (labels that ensure that the wood used comes from a sustainably managed forest).
  • PVC (great winner of the price / quality ratio) will be chosen with partitioned profiles to several isolated rooms, to maximize the energetic performance of the frame of the window.
  • aluminum for its part, will be chosen primarily for large windows because of its strength and rigidity (its price, however, is in the most expensive solutions), and for the extended range of colors proposed.

Coefficients to evaluate thermal performance

Thermal insulation coefficient
Plus Uw coefficient of a window (expressed in W / m2.K) is weak, the more it is efficient from the point of view of thermal insulation. It is good to know also that this coefficient is calculated from the coefficient of glazing (U g) and the framework (Uf). We can therefore play on the coefficient of one and the other to obtain a sufficient number.

The light transmission coefficient
It is also necessary to take into account the TL coefficient of light transmission of glass (TLW for the entire window), which impacts its ability to recover calories from the sun. The higher the solar factor of the glass, the higher its TL or TLw is and the more it lets solar radiation pass.

The solar factor
The solar factor of carpentry (sw) has an impact also and intervenes in the general calculation of the thermal performances of a window.
These coefficients are of paramount importance, since they are taken into account in the regulatory texts which detail the conditions of access to the various state subsidies and subsidies for the energy transition, to which the window change work can be done. eligible.

Financial aid for a window change

In the context of energy renovation works, a window change may be eligible for grants and subsidies from the State if it fulfills certain conditions, according to the current budget law. The first condition is to have the work carried out by a craftsman with the mention RGE (Recognized Guarantor of the Environment): it is absolutely necessary for the work to be eligible for certain aid.

Eco-PTZ (Eco Ready Zero Rate)
It is granted for the implementation of double glazed windows (for dwellings built before 1st January 1990 only) and for the replacement of at least half of the windows facing the exterior. It is granted to the landlord or the occupant of an old dwelling and the syndicate of co-owners (until December 31, 2018).
VAT reduced to 5.5%
As with all energy renovation works, the 5.5% VAT is allocated to the replacement of windows until 31st December 2018. It is not necessary for the company to be an RGE.
The Energy Bonus
It is a direct financial aid for energy renovation works (including windows, up to once per type of work) resulting from the system of energy certificates. This premium may relate to main residences as secondary. The file must be assembled before the start of work and before signature of the estimate. The premium takes into account the geographic location of the house, the number of windows replaced and the heating method of the dwelling.
CITE (Tax Credit for Energy Transition)
Windows are no longer eligible for ISCED from 1 July 2018. For 2018, window replacement work has been signed quote and a advance payment versed between the 1st January 2018 and June 30, 2013 remain eligible for 15% tax credit, the declaration to be done in 2019.

Warning: for windows, performance criteria are taken into account for eligibility for aid.

  • Windows or French windows: Uw ≤ 1.3 W / m².K and Sw ≤ 0.3 or Uw ≤ 1.7 W / m².K and Sw ≥ 0.36
  • Replacement glazing with reinforced insulation: Ug ≤1,1 W / m².K
  • Double windows (second window on the bay) with reinforced double glazing: Uw ≤ 1.8 W / m².K and Sw ≥ 0.32
  • Roof windows : Uw ≤ 1.5 W / m².K and Sw ≤ 0.36

On the same topic

  • Questions answers
    • The installation of double glazing on old windows in 5 questions
    • Are PVC windows covered by the decennial?
    • What tax credit for replacing windows?
    • Is there a tax credit for air conditioning and double glazing?
  • DIY tips
    • Changes in taxes and deductions in 2019
    • What are the conditions to benefit from the energy bonus?
    • Benefit from aids for energetic renovation in 2018
    • Install a window to better isolate: how to make a choice?
    • Replace an old window with a PVC window
    • Mounting a roof window
    • To put a double glazing in renovation

This may interest you


Video Instruction: Why It's So Hard For Millennials To Buy Homes