In case you've made your mind up to replace your doors and windows, you are most likely looking at many businesses locally on the internet, maybe jointly with one or even two of the large national companies that advertise on tv a good deal.
Evidently, your intent is to receive top-quality merchandise at the best possible cost, and that is fair enough. Of course, you'll have to make an appointment to get a salesperson to call so he can measure your windows and give you an accurate cost. That is where things can begin to get complex. You can choose double glazed windows and noise reduction windows in Sydney through the internet.
A semi-detached home would save between 65 and 80, and a mid-terrace would save between 50 and 60, a detached bungalow the same, and a mid-floor flat would save 30 to 35. So yes, you will make savings, but they are not vast amounts of money.
And remember that this is replacing single glazing with double glazing: if you already have an older type of double glazing, the savings would be less. So, don't believe a salesman who promises that you will save a small fortune on heating bills, because you won't. Then there is the question of the type of material from which you want your windows made.
uPVC windows are inexpensive, lightweight, very low maintenance, and can be made in any colour you like. However, some designs have thick, chunky frames, and welded frames can also distort over time if they are not reinforced.