When Mandy & I bought the house we knew that the very large (1.8 x 1.8) aluminium windows that had been put in sometime in the 80’s would have to be replaced. When we were renovating one of the two south facing bedrooms regularly had 1cm of ice on the inside of the window during the winter and condensation was a constant problem.
Would have loved to replace all the windows but the cost in Australia is still very high. The aluminium windows only had 3mm glass in them divided into one pane being half the window and then a double hung unit. The largest area shook and wobbled and eventually cracked so something needed to be done.
When we renovated our own home (www.greentasreno.wordpress.com) we looked at the possibility of installing double glazing and went through all the alternative framing available. Aluminium without a thermal break is nearly as thermally inefficient as single glazing as aluminium transmits hot and cold very, very easily; wood framed is an alternative but quite expensive to have made; aluminium with a thermal break is a ggo option and available; Upvc is also available.
Looking at the alternatives Mandy & I settled on Upvc as it is maintenance free and a little cheaper than aluminium thermal break. There were three suppliers of Upvc windows that I found in Tasmania:
We decided after getting quotes that we would go with Elite. They manufacture their windows in Tasmania from German mouldings and the double glazing is from Pilkington glass made in Australia at the time of writing this blog.
After coming to measure up the windows were made at their factory and then delivered and fitted. The main bedroom was done first and then after a little while the second bedroom. The units were Eoropean tilt and turn models. Very well sealed when closed they can open inwards fully when the handle is twisted one way and tilt outward for ventilation when the handle is twisted the other way.
The difference in the way the whole house behaved thermally was amazing. Come the winter there was no condensation and definitely no ice on the inside of the windows.
At some point we will look at replacing more of the windows.
A good starting point to understand the terminology such as U ratings etc is the Window Energy Ratings Scheme You can see if the manufacturer has their windows in the scheme and if they have how they rate.