Window Specs

The plan is to spec double-glazing for the RT2012 survey but budget for triple glazing on the basis that it’s much nicer to have triple but to meet the spec we need to under-promise and over-deliver! Here are the window specs and prices from Fenetre24.fr (German made :-))

Triple Glazing

For all these triple-glazed uPVC windows and doors, Uw = 0,87.

1800 x 1200 mm Triple-Glazed 3 Vantaux Window
  • Matière: PVC
  • Profilé: IDEAL 5000 (5 chambres avec 3 joints)  18,70 €
  • Couleurs: Blanc
  • Type de fenêtre: 3 vantaux – modèle de base
  • Sens d’ouverture: 3 vantaux – gauche fixe, centre OB-DIN droit, droit fixe
  • Largeur totale: 1800 mm
  • Hauteur totale: 1200 mm
  • Répartition Hauteur 1: 1200
  • Répartition Largeur 1: 500
  • Répartition Largeur 2: 800
  • Répartition Largeur 3: 500
  • Ferrures: Sécurité de base
  • Vitrage
  • Vitrage: Double vitrage Ug 1,1 selon DIN EN 673
1600 x 2100 mm Triple-Glazed French Door
  • Matière: PVC
  • Profilé: IDEAL 5000 (5 chambres avec 3 joints)  23,50 €
  • Couleurs: Blanc
  • Type de porte-fenêtre: 2 vantaux – modèle de base
  • Porte-fenêtres à deux vantaux: 2 vantaux – oscillo battant gauche, oscillo battant droit avec meneau central
  • Largeur totale: 1600 mm
  • Hauteur totale: 2100 mm
  • Répartition Hauteur 1: 2100
  • Répartition Largeur 1: 800
  • Répartition Largeur 2: 800
  • Seuil bas pour porte balcon: Non
  • Ferrures: Sécurité de base
  • Vitrage: Triple vitrage Ug 0,6 selon DIN EN 673 92,78 €

Double Glazing

For all these double-glazed uPVC windows and doors, Uw = 0,91.

Hardly any difference in price, which is surprising.

1800 x 1200 mm Double-Glazed 3 Vantaux Window
  • Matière: PVC
  • Profilé: IDEAL 4000 (5 chambres avec 2 joints)
  • Couleurs: Blanc
  • Type de fenêtre: 3 vantaux – modèle de base
  • Sens d’ouverture: 3 vantaux – gauche fixe, centre OB-DIN gauche, droit fixe
  • Largeur totale: 1800 mm
  • Hauteur totale: 1200 mm
  • Répartition Hauteur 1: 1200
  • Répartition Largeur 1: 400
  • Répartition Largeur 2: 1000
  • Répartition Largeur 3: 400
  • Ferrures: Sécurité de base

  • Vitrage: Double vitrage Ug 1,1 selon DIN EN 673

Choosing Windows

How Many

To meet RT2012 we need 1/6 of the floor space of the house to be windows. Our current plan is about 120m2 so that means about 20m2 of windows.

U-Values

The two important U values for windows are:

  • Ug for the glass
  • Uw for the entire window

What Material

I really like the look of wood and aluminium, but since the plan is to build a mortgage-free home within our budget, they are out of our reach financially. As is triple glazing. So we’re looking for double-glazed uPVC.

Luckily the U values for uPVC seem to be better than for wood (pine, anyway. Oak is way out of our reach.) Given our remit is to build the warmest most insulated house we can on our 100K budget, uPVC it is!

There’s some good info about that on this website.

What Size?

We want the biggest windows we can afford! It looks like there are some standard sizes (based on price) so it may be that we have to base our decision around that. 

Window Suppliers

Much research to do on this front as the prices and u-values vary widely.

Also want to see what price a 3-pane window with a central opening pane (the two outer ones fixed) compares to a 2-pane one.