Windows / Doors / Porches - Sustainable HomesSustainable Homes

The overall style of the window unit.
The type of glazing used - Checkout the u-value of the glazing units.
In fitting glazed window units to the house - thermal bridges should be kept to a minimum. Thermal bridges are small poorly insulated areas. Alert the potential installers that you are aware of this possible issue, prior to giving the go-ahead; ask, also, about the proposed insulation of the surrounding wall prior to the fitting. Also, insist that there should be no air-leaks between window and building envelope.
In the case of porches, any brick or block walls should be well insulated.

To get some idea of what you should be seeking from a glazing contractor here are some typical u-values for the different elements often used in the installation of Windows, Doors, or Porches:

- Cavity and single block walls (for Porches)- ranges from 0.15 to 0.38 W/m²K
- Air filled double glazing - ranges from 2.8 to 3.0 W/m²K
- Argon filled double glazing - ranges from 1.1 to 2.5 W/m²K
- Argon flled and low E double glazing - ranges from 1.6 to 2.3 W/m²K
- Argon filled triple glazing - ranges from 0.6 to 0.7 W/m²K

Advantages of Windows,Doors and Porches:

- - Lower energy bills.
  - Improved BER energy rating.
  - Reduce carbon footprint.
  - Reduced draughts if installed properly.

Disadvantages of Windows,Doors and Porches:

- - High installation costs.
  - Temporary disruption to your home during installation works, especially for windows.