Window shopping has never been so important

If you about to embark on renovating or building a new home you will need to consider going window shopping.  Yes, literally.

The correct choice of windows, their size, style, placement, and configuration can influence the energy efficiency of your home, so window shopping has never been so important. 

This is because windows can allow more heat loss/gain and be more susceptible to air leakage than the walls, ceiling or floor of your home.  It is no wonder then that window selection and placement are such an integral part of building an energy efficient home.  With their cost often in the order of 15% of the price of a new home, making the right decision is important to reap reward on what should be seen as a long-term investment. 

Who would have thought there would be so many decisions to make when window shopping?  







Lets try and simplify the decision making process to six main considerations:

1)     Purpose of the window; each window must have a purpose in your home, and any decision needs to take this purpose into account, this may be:

a.     Function: light, views, ventilation, energy efficiency (eg solar heat gain in winter); or

b.     Appearance

2)     Style of the windows, including the layout of flyscreens and window openings, will ultimately come back to the purpose of the window, however when it comes to the style of the window you are spoilt for choice:

a.     There are eight main window styles to choose from; sliding, awning, single hung, double hung, casement (side hung), louvre, fixed, or bi-fold.

b.     You should also consider air leakage potential, as hinged style openings may be better for air tightness, and window seals will also be important and will vary amongst manufacturers (elastomeric gaskets may be better than brushed or foam gaskets).

3)     Frame material is important from an energy efficiency, fire rating, and maintenance perspective.  Once again there are a selection of frame materials from which to choose:

a.     Frame material options include aluminium, timber, uPVC, or composite (eg aluminium on the exterior and timber on the interior).

b.     The insulation value of the frame material should be considered for energy efficiency, this includes products that offer thermal breaks within framing systems.

4)     Glazing options are abundant and the decision is important as the selection will influence the overall energy efficiency, privacy, noise reduction, and security the window may provide.  Glazing should also consider safety of home occupants.  Energy performance of glazing is made up of Solar Heat Gain Coefficient (SHGC), Heat Flow (U Value), Infiltration (Air Leakage), and Visible Light Transmission; more information on these terms and their meanings can be found here: http://www.afrc.org.au/ConsumerInfo.htm

a.     The first glazing decision is whether to have single glazed, laminated, or double glazed.  (Double glazing or Insulating Glass Units (IGU) usually have air gaps of around 12mm (optimal) filled with either air or argon gas).

b.     Glazing options include float glass, patterned glass, laminated safety glass, toughened safety glass, toughened laminated glass, coated glass, mirror, screen printed glass, formed glass, security glass or self cleaning glass and different combinations of these may be installed on double glazed units.  Glazing products vary too and include VFloat; high performance tones such as SuperGreen; Low E glass such as ComfortPlus, Evantage, EnergyTech, SolTech; and thermal insulating glass units such as ThermoTech IGUs.  More information on these glazing options as well as glazing products can be found here: www.viridianglass.com

5)     Locking mechanisms vary between windows styles and manufacturers, and security and air tightness may be considered when making this decision.

6)     Colour; last but not least is the colour of your window frames, and the colour of the glazing element in your windows.  These options may vary between manufacturers.