We recently double-glazed our entire house. Our north side is mostly windows, floor-to-ceiling, for the passive heating (we live exposed at 1300m in the Snowy Mountains). The windows cost $30+ (we had some converted to double-glazed sliding doors). This winter the temperature outside might not often be getting above 5C and obviously drops big at night, but with our storage heaters the temperature inside is at least 20C. When we switch the fan off the heaters overnight, the temperature might drop to 17C at the far, coldest end (whereas last year the coldest inside we got to was 6C). Double-glazing isn't the only insulation need (good wall and roof is important), but for our needs it has made this a comfortable, cosy winter house. We'll have to wait and see what summer is like though.

Look at using a Heat Pump type of hot water system. Very efficient for an electric unit. Not as good as solar such as Evacuated Tube so look at these as well. Solar power with a Heat Pump or Evacuated Tube would be fine. These aren't the cheapest options but the extra costs in the whole scheme of things is minor. A reverse cycle heating and cooling using solar power would be a good option. Wood heating is still very good if you have access to cheap dry wood otherwise its not really worth the trouble. Using a wet back type of heater for hot water would be good but again wood fuel can be a problem. Adelaide summer and needing hot water also not ideal.

We installed a skylight over shower (velux fixed) in a tiny ensuite and I would highly recommend. It looked absolutely amazing and was heavenly to shower under the sky. We only had the house for a year and sold it (about to install another skylight over shower in our new house), so I can't comment on the long term, but no mould problems or condensation drips. I think if anything the sunlight was actually helpful to dry up moisture. We live in Tasmania so I'd doubt condensation dripping would be a problem elsewhere. We had a fan installed not in the cavity with the skylight but just on the ceiling next to it. In the second bathroom we put in a skylight over bath and put an extractor in the skylight cavity as the ceiling was higher. Could not feel a draught- so I think the question of where to put fan really depends on ceiling height. Do the skylight over shower!! You will not regret it. It really takes your bathroom to another level and there are really no maintenance problems if installed properly with custom flashings. I found velux quite repellent of dirt etc, we did not need to clean after a year (one flat roof skylight, one very large sloped) and I have seen velux skylights looking great with no cleaning for 7 years plus.

Single glazed vs double glazed windows As its name suggests, a single glazed window is made using one pane of glass. This means the only thing between your home and the outside temperature is a pane of glass which doesn’t give adequate insulation. A single glazed window is not very efficient when it comes to heat loss or gain. Double glazed windows use two panes of glass with a vacuumed air gap between them which creates an insulated barrier. Double glazed glass is laminated or tinted, but is similar to single glazed window glass otherwise. What are the benefits and disadvantages? Benefits The most obvious benefit of double glazed windows is the increased thermal efficiency. This means it is easier to maintain the temperature inside your house. This is important if you use air conditioners or central heating or cooling systems. Other benefits include: Energy-efficient Sustainable and environmentally friendly Reduces outdoor noise Durable with low maintenance Increases the value of your house Less condensation on your windows Disadvantages As double glazing is so efficient, any heat that enters your home during the hotter months is easily stored. This means you should take extra measures to alleviate the problem in summer. Two options include applying UV protective coating or using window films. Remember, these additional protective layers will increase the cost of your installation.